Science Horizon

Volume 5 Issue 12 December, 2020

President, Odisha Bigyan Academy Editorial Board Prof. Pramod Chandra Mishra Prof. Niranjan Barik

Editor Prof. Ramesh Chandra Parida Er. Mayadhar Swain Dr. Choudhury Satyabrata Nanda Managing Editor Dr. Rajballav Mohanty Er. Bhagat Charan Mohanty Secretary, Odisha Bigyan Academy Dr. Nilambar Biswal

CONTENTS Subject Author Page 1. Editorial : Energy Security of India Er. Mayadhar Swain 2 2. Energy Resources Prof. Balaram Sahoo 5 3. Harnessing Nuclear Energy Dr. Mridula Mishra 12 4. Thermal Power Plant: Theory & Mechanism Ansuman Dash 16 5. Hydropower Resources Er. Jaya Prakash Chand 20 6. The Need For Renewable Energy Sources Dr. Sanjeeb Kumar Das 25 7. Solar Energy Satyaranjan Jena 31 8. Wind Energy Subhendu Kumar Santra 34 Dr. Banishree Mishra 9. Waste to Energy: An Ecofriendly and Effective Municipal Prof. Pramod Chandra Mishra 42 Solid Waste Management Strategy 10. Energy From Sea Dr. Arjyadhara Pradhan 46 Dr. Babita Panda 11. Geothermal Energy: A Never-Ending Energy Soumyashree Nanda 50 Source Beneath Our Feet Shreerup Goswami 12. Geothermal Springs of Odisha - A Renewable Energy Resource Sahid Ummar 59 13. Hydrogen Energy Er. Ramesh Chandra Sahoo 61 14. Biodiesel - Fuel For Thought Dr. Manas Ranjan Senapati 64 15. Fuel From Carbon Dioxide Dr. Ramesh Chandra Parida 66 16. Towards Clean Energy Dr. Nikhilananda Panigrahy 68 17. Energy Scenario in Rural Area - Tips for Renewable Sources Dr. Bijay Ketan Patnaik 71 18. Contents of the ‘Science Horizon - 2020’ 75 The Cover Page depicts : Nuclear, Thermal and Hydroelectric Power Plant Cover Design : Kalakar Sahoo DECEMBER, 2020

// EDITORIAL // ENERGY SECURITY OF INDIA

Energy is one of the most important has created a great environmental problem. building blocks in human development, and as Carbon dioxide is a greenhouse gas which such, acts as a key factor in determining the causes global warming and climate change. economic development of any county. Future India has committed in the Paris Agreement to economic growth of a country depends on the reduce greenhouse emission by 30-35% from long-run availability of energy from sources 2005 level and to have 40% of electricity that are affordable, accessible and from renewable sources by 2030. So naturally environmental friendly. the share of thermal power will decrease. But India, one of the fastest growing major it is not possible to drastically reduce thermal economies, is also the fastest growing energy power generation because renewable energy consumer of the world. With over a billion is not highly reliable. people, a fifth of the world population, India India, with 17% of the world population, ranks sixth in the world in terms of energy has just 0.8% of the world’s known oil and demand. The demand for energy is growing at natural gas resources. As on 31.03.2018, India about 10% per year and in coming years it will has total reserves of 594.49 million tonnes accelerate further if ‘Make in India’ programme (0.5% of global reserve) of crude oil and is carried out earnestly. At the time of 1339.57 Billion Cubic Meter (BCM) of natural independence, the installed capacity of electricity gas. Today, oil accounts for 30% of India’s generation in the country was 1362 MW and as primary energy use and it is increasing year by on 31st October 2020 it has reached at 373436 year. India’s domestic production is not MW. Similarly in 1947, the per capita sufficient to meet its demand and it imports consumption of electricity in the country was 16 70% of its crude oil needs. Natural gas currently units and by March 2019 it was 1181 units. provides 8% of India’s primary energy supply India’s more than 50% of energy needs and most of it comes from domestic sources. is derived from coal, mainly for electricity. Nuclear power is clear and environmental There is plenty of coal available in India. As on friendly. India has 22 nuclear reactors in 31.03.2018 the estimated amount of coal and operation with installed capacity of 6,780 lignite reserve was respectively 319.04 billion MW. Further 6 reactors with capacity of 4,800 tonnes and 45.66 billion tonnes and it will MW are under construction. The share of remain India’s most important energy source nuclear power is less than 2% in India’s total for the decades ahead. However, the percentage electricity generation. India has planned to of coal in India’s energy mix will decline in increase the capacity to 64,000 MW by 2032. future. It is due to the emission of carbon The main obstacle for growth of nuclear power dioxide from the combustion of coal which

2 Science Horizon DECEMBER, 2020 in the country is the availability of uranium, Apart from hydropower other renewable the fuel for the reactor. sources are solar, wind, bio-energy and small After India-US nuclear agreement, we hope hydel, on which India is emerging as a new to import uranium for our nuclear plants. In fact, normative player. The total potential for this agreement has pushed the energy security to renewable power generation in the country as on the core of India’s foreign policy. After this, 31.03.2018 is estimated as 1,096,081 MW. This India has also made civilian nuclear agreement includes solar power of 748,990 MW (68.33%), with a number of other countries including wind power of 302,251MW (27.58%), small- France, Russia, Canada, Australia, Japan and U.K. hydro power of 19,749 MW (1.80%), biomass Further, thorium is another energy metal power of 17,536 MW (1.60%), 500 MW which is available in plenty in India. Research (0.46%) from bagasse-based cogeneration in is going on in the country to harness nuclear sugar mills and 2,554 MW (0.23%) from waste- power from thorium. to-energy. Keeping in mind our commitment to the Paris Agreement, India is pursuing hard to India has immense amount of hydro- increase the share of renewable power. It has electric potential. As estimated by Central fixed a target of 175,000 MW to be installed by Electricity Authority, the hydroelectric potential 2022. Out of this share of solar, wind, bio- of the country is 148,700 MW at 60% load energy and small hydel is respectively 100,000 factor. The present installed capacity of MW, 60,000 MW, 10,000 MW and 5,000 MW. hydropower is 45,699 MW which is 12.25.% of total electricity generation capacity in the country. India has a great potential to generate Although India has tremendous potential, there solar power. Most part of India have 300-350 are many difficulties and obstacles for its sunny days in a year, which is equivalent to development. Most of the remaining hydro over 5000 trillion kWh per year-more than potential lies in the Himalayan region with difficult India’s total energy consumption per year. The terrain for access. Further, as large hydro projects daily average solar energy incident over India 2 submerge large areas, particularly forest land, varies from 4 to 7 kWh/m / day with about there is opposition from environmentalists. For 1500 - 2000 sunshine hours per year grid stability, the share of hydropower should be (depending upon location). India had launched about 40%. But in our country it has gradually Jawaharlal Nehru National Solar Mission in decreased from 40% in 1980 to 12.25% in 2020. 2010 with the target of installing 20,000 MW Government of India has taken initiative to install of solar power by 2022 and it was upgraded to large hydro projects with total capacity of 50,000 100,000 MW in 2014. As on October 2020, MW. Although, the program was launched in the installed capacity of solar power in the 2003, no appreciable progress has been made till country is 36,317.57 MW and considering the date and only one project of 96 MW capacity has projects under construction, it can be assured been commissioned in Sikkim. Hydropower is a that we may exceed our target. It is to be noted renewable and conventional source of power which that the two largest solar power plants in the should be encouraged. world are in our country at Bhadla in Rajasthan

Science Horizon 3 DECEMBER, 2020

(2,250 MW) and Shakti Sthala in Karnataka mills. Further, electricity is generated from urban (2,050 MW). municipality solid wastes called waste-to-energy. India is endowed with a large, viable and At present, the installed capacity of bio-energy economically exploitable wind power potential. is 10,146 MW and waste-to-energy is 168.64 At present, India’s installed capacity of wind MW. power is 38,263.05 MW, mainly spread over There is potential of 40,000 MW ocean Tamilnadu (9,304 MW), Gujarat (7,542 MW), energy along the 600 km of coast. This is in Maharashtra (5,000 MW), Karnataka (4,791 form of tidal energy, Ocean Thermal Energy MW), Rajasthan (4,300 MW), Madhya Pradesh Conversion (OTEC) and wave power. Although (2,520 MW) and Andhra Pradesh (4,093 MW). research for exploring this type of energy has India ranks 4th in the world in wind power started in 1980s, we have not progressed much. generation after China, USA and Germany. According to the estimate of the Indian Small hydel plants, have become government, the country has a potential of necessitated to avoid the submergence by large 8,000 MW of tidal power. This includes about hydro power plants. Present installed capacity 7,000 MW in the Gulf of Combay in Gujarat, of small hydel in the country is 4,740 MW. 1,200 MW in the Gulf of Kutch and 100 MW Geothermal power is generated from in the Gangetic delta in the Sundarbans region the conduction of thermal energy in the form of West Bengal. It is not being developed due of heat from Earth’s interior to its surface. The to high capital cost ranging from Rs.30 Crore heat comes alongwith water or steam, which to Rs.60 Crore per megawatt. are called geyser. Although it is cost effective, Coal bed methane (CBM) is the new reliable and environment friendly, it is limited source of energy explored recently. Having to areas near tectonic plate boundaries. In India, the 5th largest proven coal reserves and being the potential sites for geothermal power are the 4th largest coal producer in the world, India Puga (Ladakh), Manikaran (Himachal Pradesh), has significant prospects to harness this type Tattapani (Chhatisgarh), Cambay (Gujarat), of energy. Estimated CBM resources in India Surajkund (Jharkhand) and Chhumathang is 2600 BCM in 12 states of India. (Ladakh). India is establishing a geothermal In coming years, India has to generate power plant of capacity 3 MW experimentally more electricity from renewable sources mainly at Puga Valley. The estimated potential of from solar and wind. Further, India aims to geothermal energy in India is about 10,000 increase its nuclear power capacity and reduce MW. The contribution of geothermal power its dependence on thermal power. Oil and natural will not be impressive in near future. gas exploration will help India reduce its imports. Biomass is an important energy source Achieving 90 percent self-sufficiency on energy contributing to more than 14% of the global resources will enhance our economic growth. energy supply, mainly in rural areas. India is „ generating electricity from agriculture and forest Er. Mayadhar Swain residues and from bagasse cogeneration at sugar Editor

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ENERGY RESOURCES

Prof. Balaram Sahoo Without energy, there would be no life, to form the hydrogen atom, and two electrons nor would anything work at all. Energy is to form the helium atom, and thus the very available everywhere; it can be neither created, first building blocks of matter were born. nor destroyed. In 1905, Albert Einstein One atomic mass unit (u) is defined as 1/ published five important papers. One of these 12th the mass of a carbon-12 atom = was on the theory of relativity where he stated 1.66x10-27 kg. that the speed of light is constant, mass is a A common household flashlight uses a 1.5 form of energy, and derived the equation he is V battery which provides to each electron 2 celebrated for, E = mc , which signifies the an energy equal to 1.5 eV. relationship between energy and mass. E is the 1 eV = 1.602x10-19 Joule; 1MeV = 106 eV change in energy, c is the speed of light, and m is the corresponding mass. As an example, 1 atomic mass unit would, by this equation, release The first atomic bomb used in warfare and an astounding 931 MeV of energy. This dropped over Hiroshima, used about 1 kg remarkable revelation by Einstein changed how of fissionable uranium, and generated 63 scientists had been thinking about energy. TJ of energy, or 17.5 GWh, the peak energy of a powerful hurricane or enough energy About 13.7 billion years ago, space, time to power a town for a year. and matter, came into being in a momentous event, an extremely dense and hot explosion, By the time the hydrogen and helium called the Big Bang. The UNIVERSE, in the atoms were formed, the heat generated by the first few millionths of a second, involving Big Bang had cooled down, and the dense highly complicated events, expanded rapidly gases had thinned and spread out as the taking on a tangible form. This process lasted Universe expanded. About 1000 million years for a very small fraction of a second, and is later, the huge clouds of gas, held together by called inflation. Thereafter, the process slowed, gravity, collapsed to form galaxies and clusters and many different particles, such as quarks of galaxies. Gradually, as time passes, stars and electrons came into being. These very began to form inside these galaxies. About 5 quarks clumped together to form particles, billion years ago, our very own galaxy, the known as protons and neutrons. In turn, these Milky Way, and the Sun were born. Planets protons and neutrons combined to form the began to form around the Sun. Our Earth is the atomic nucleus, which captured one electron third planet from the Sun. This brief

Science Horizon 5 DECEMBER, 2020 introduction will be used to show sources of In the earliest stages, man used his usable energy on our Planet. muscle energy to do work. In time, he tamed Fundamental Sources of Energy animals to do this work, and gradually used stone to make simple tools to assist this. 1. Gravity: In space - formation of galaxies, Once fire was discovered, he burnt wood to stars, planets, other celestial bodies and cook his food, keep his cave warm, which led to their motion in space. On Earth - charcoal being burnt to provide greater amount formation of clouds leading to rain, tides of heat, and also attain higher temperatures in the ocean giving rise to hydroelectric thereby leading to extraction of metals. His power projects. Fact - without gravity, energy requirement was modest. Gradually neither force nor work would exist. civilization progressed; by the eighteenth 2. Nuclear fusion: In space - nuclear century the steam engine was invented leading syntheses of chemical elements in stars, to an industrial revolution, and a greater need supernova explosions, intergalactic for energy. Modern human uses 150 times as reactions; On Earth - nuclear fusion much energy as his ancestors did. reactors like Tokamak. Fossil Fuels 3. Nuclear fission: radioactivity that keeps The origin of fossil fuels and biomass the interior of the Earth warm, nuclear began with the most spectacular photosynthetic power plants. chemical reaction carried out in nature. 4. Radiation: solar energy, solar battery, Without photosynthesis, no life on earth would wind power, photosynthesis in plants exist. Photosynthesis is the reaction where 5. Chemical bonds: fossil fuels, petroleum, carbon dioxide and water in the atmosphere natural gas, hydrogen production, combine in the presence of sunlight to form semiconductor materials, hydrogen the organic molecules of sugar, and nature’s storage. most important, complex product chlorophyll. Energy Resources: Present and Future Sugar nourishes plants, and oxygen supports Perspective life on earth. For example, consider the The Sun provides nearly all energy on following reaction:

Earth. The sun’s radiation travels through 150 6CO2 + 6H2O o C6H12O6 + 6O2 million kilometers of space to earth. The This reaction is endothermic, i.e., it energy in the interior of the earth is not from absorbs heat energy from the solar radiation this radiation; it is instead produced by the and is reversible. In the reverse process, it radioactive disintegration of heavy elements, produces heat energy, water and carbon dioxide. such as thorium and uranium, which keep the Endothermic reactions store energy in the core in a molten state called magma. form of chemical potential energy.

6 Science Horizon DECEMBER, 2020

Organic matter, plants and animals buried dioxide, methane and water, absorb the infrared under the surface of the earth, in the absence radiation, preventing it from escaping back of air, undergo slow chemical reactions, and into space, and reradiate it in all directions, over millions of years convert into including the earth. Methane is released from hydrocarbons, oil and natural gas. Under high paddy fields, domestic animals, cows, termites pressure and at varying temperatures, organic and certain bacteria in large quantities. Human matter forms bituminous and anthracite coal activity has increased the amount of also known as fossil fuels. At still higher greenhouse gases in the atmosphere, and the temperatures, graphite, a more pure form of amount of heat reflected back to the earth has carbon is formed. With the exception of caused the temperatures to rise across the graphite, these fossil fuels are used to generate globe. electricity that run our factories, transportation The present level of carbon dioxide in needs, roads, buildings and bridges, and are the earth’s atmosphere is 400 parts per million also used in various household requirements. (ppm) which is much higher than it was the last The use of fossil fuels has been a major step 650,000 years. It is estimated that it will in raising the economic standard of countries, surpass 500 ppm by the year 2050, unless and in general, made the world richer and there is some kind of radical intervention. prosperous. Fossil fuels provide about 70% Almost all of the 25 hottest years on record of the energy consumed by us today, however, have occurred in the past 40 years. Stabilization the major disadvantage is that they are not a of carbon emission requires a tangible renewable source. While it appears that these blueprint to nurture economic growth while resources are inexhaustible, in reality, with also building a decarbonized energy the current rate of consumption, they will be infrastructure. depleted in about 200 years. Another Toxic emissions: Besides carbon potentially hazardous effect of burning fossil dioxide, coal-fired power plants emit fuels is the danger they pose, by rising considerable amounts of sulphur dioxide and temperatures, to all of the living world. The nitrogen dioxide. Sulphur dioxide forms biosphere, home to all living beings, plants, sulphate particles in the atmosphere causing animals and humans, is suffering greatly due acid rain and particulate pollution, a to this greenhouse effect. contaminant leading to thousands of premature The Greenhouse effect is a prerequisite deaths from lung disease. Nitrogen dioxide for life on earth. It occurs when infrared combines with hydrocarbons causing smog (heat) radiation is retained within the which results in increase of ground level ozone. atmosphere. Most of the sunlight reaching Coal fired power plants produce tons of the earth is absorbed at the surface. mercury. Mercury is highly toxic, it oxidizes Atmospheric greenhouse gases, namely carbon to form methyl mercury which accumulates in

Science Horizon 7 DECEMBER, 2020 the tissues of fishes. Methyl mercury in food, the Italian physicist, Enrico Fermi, predicted such as fish, is a particular health hazard as it that if various heavy elements are bombarded is easily absorbed in the body though the with electrically neutral neutrons, they could stomach and intestines. penetrate the nuclear of the heavy element and Mining and transport: Coal mining is far new elements would form. In 1930, (prior to from perfect. Miners suffer from coal mine these two discoveries above), physicist Lise floods, cave-ins, fire and explosions. Meitner and chemist Otto Hahn working in Transportation practices damage the landscape, Berlin, bombarded a uranium solution with pollute water, harm people and the ecosystem. thermal neutrons. Otto Hahn and his student, In spite of all these disadvantages, coal is Strassman, discovered that uranium, instead plentiful and inexpensive, so its usage is of absorbing neutrons, broke down into two burgeoning in developed as well as developing lighter elements, one of those being barium, countries. The new power generating facilities with a release of energy. This discovery is that are going to be installed within the next historically profound because two nuclear decade will introduce enough carbon dioxide bombs were dropped over Hiroshima and into the atmosphere to cause unimaginable Nagasaki in the Second World War with catastrophes. Therefore, efforts are underway devastating effects. The war ended in 1945, to retain the carbon underground. and scientists focussed on using a nuclear reaction to harness a source of power. Frozen gas: Methane hydrates are found along coast lines around the world. Scientists Nuclear Fission: have estimated that if technology could be 235 1 144 80 1 92Uo 0 n 56 Ba  36 Kr  3 0 n  210 MeV developed to harvest them without an Nuclear power stations provide slightly explosion, they would provide energy at the more than a sixth of the world’s electricity. current rate for two thousand years. The gases Along with hydroelectric power, which provides emitted by microbes that digest organic matter about one-eighth of electricity, it is the major form sediments which remain encapsulated in source of carbon-free energy. With the rapid ice crystals. In comparison to carbon dioxide, industrial growth of developing countries, methane is about 10 times more efficient in global electricity needs are going to double by trapping heat. Japan and USA have made some 2050. Constructing hundreds of nuclear power progress towards harnessing methane from plants is expected to meet the need without the sea bed. However, more research is needed additional emission of carbon dioxide. Growth before it is collected on a large scale. of nuclear power plants suffered a setback in Nuclear Energy Options the public eye due to the devastating In 1932, the English physicist, James consequences of nuclear accidents at Chernobyl, Chadwick, discovered the neutron. In 1934, Three Mile Island and Fukushima. However,

8 Science Horizon DECEMBER, 2020

world has implemented a fool-proof system for storing nuclear waste products. They contain highly radioactive materials which are harmful to humans as well as the rest of the living world. The common method being used now is storing the waste products in steel- reinforced concrete chambers hundreds of meters below the surface of the earth. This storage should also be leak-proof for nuclear power plants have demonstrated marked millennia. reliability and efficiency in recent times. Renewable Energy Though there is an ample supply of uranium, Solar cells, wind power and bio-fuels: construction of power plants has proved costly. Solar energy, windmills and bio-fuels are No country is willing to consider nuclear considered to be renewable sources of energy. installations without an economic viability. Until now, coal and gas-fired power stations, With intensive research and technology followed by nuclear energy and hydroelectric development, nuclear power plants will be projects dominated the energy scene in the competitive, and many will be built. world. Hydroelectric projects provide about Nuclear Programme of India: Homi 7% of energy demand. Though it is clean, Bhabha formulated India’s three-stage nuclear cyclical, it has limited scope of expansion programmes in 1950. It was a long-term plan since most of the rivers have already been for the country to achieve a secure power tamed for generating energy. Industrial growth supply. The plan was based on the use of and economic progress continues, demand for uranium and thorium reserves found in energy based on coal, oil and natural gas also monazite sands of coastal regions of India. keeps growing. As a result, carbon emissions Probably, India has the largest deposit of will also keep rising. monazite sand in the world. Currently, there We live in an era of new opportunities. are 11 power plants, but there is a great need Solar cells, wind power and bio-fuels are no for more nuclear energy. The first power longer fashionable as they were in the 1970s. plant was built at Tarapur, near Mumbai. Demand for these sources of energy is a Currently, there are 22 operating reactors with reality now. an installed capacity of 6,780 MW. Solar cells: Solar cells are also known as Nuclear waste disposal: Apart from the photovoltaic cells. They use semiconductor cost of building nuclear power plants, safe materials to convert sunlight into electricity. waste management of the byproducts is a Currently, the global generating capacity is difficult hurdle. As of now, no country in the quite tiny, less than about 0.2% of global

Science Horizon 9 DECEMBER, 2020 power generated. Nevertheless, it is the most saving power from thermal power stations for promising field, with the capacity to produce industrial and manufacturing uses, and reducing 10,000 times as much as the world needs. the carbon emission at the same time. Solar cells are made from a wide range of Windmills: Wind power is growing at a materials. Traditionally, multi-crystalline similar pace as solar energy, and it is being silicon wafers have dominated the world use. promoted in India where wind flow is reliable Now, thin-film silicon cells and other and can provide power throughout the year. devices composed of plastic or organic The only drawback is they need a wide area to semiconductors are available in the market. operate and pose some risk to aircraft. These are cheaper to produce than silicon Green fuels: Development of bio-fuels will cells. Though these are less efficient in replace a part of the oil consumption by motor converting light to electricity than crystalline vehicles. The most common bio-fuel is ethanol silicon wafers, research and developments which is usually made from corn and blended promise an improvement in the ability. with gasoline. The impact of ethanol on the Resurgent photovoltaic cells are gaining environment is ambiguous. Though substituting popularity. Solar thermal systems which ethanol for gasoline reduces greenhouse gases, collect sunlight and generate heat have received there are doubts regarding the agricultural a boost. For a long time, they have been used practices used to grow corn, most particularly to provide hot water for homes and factories, the environmental degradation due to over use Stirling engines (named after the discoverer, of fertilizers and agricultural pesticides. Robert Stirling) which operate by a cyclic Each of these renewable sources of process of compression and expansion of air energy is at a critical stage. Investment, convert heat energy to mechanical energy. innovation and marketing are the need of the Now, they have been redesigned to convert hour to make them popular. Governments and heat directly into electricity. Mirrors are power suppliers must take initiatives to secure arranged so as to focus light on a Stirling a promised progress. engine in a device while a working fluid circulates between hot and cold chambers. Future of Energy The fluid undergoes expansion as the sunlight Preventing global warming has become heats it up. It then pushes a piston that drives a challenge for all countries and scientists. a turbine. The world needs carbon-free energy to save As far as India is concerned, sun shines the living world. Humanity must accept the on its face in abundant quantities and therefore, challenge and endeavour towards a marathon there is a push to store solar energy using change in technology. solar panels on rooftops of houses, cars and Using hydrogen to fuel cars might buses, schools, hospitals and offices, thereby eventually reduce oil consumption and carbon

10 Science Horizon DECEMBER, 2020 emission. The present state of technology shows hydrogen fuel cells could be commercially available. Automakers have to develop safe, inexpensive and durable models that can go significant distances before needing to be refuelled. Energy companies have to provide hydrogen at affordable prices. Fusion Reaction Harvesting Hydrogen: Currently, Nuclear fusion produces energy by combining hydrogen is produced at high temperature atoms rather than splitting them. The sun and cracking of natural gas and petroleum. Oil stars harness this strong thermonuclear force refineries use it to purify petroleum products. to fire themselves. Fusion plants could produce Hydrogen is used to manufacture ammonia by gigawatts of electricity from just a few fertilizer industries. Hydrogen production kilograms of fuel. now uses 2% of global energy. Electrolysis and biomass decomposition, using suitable Hydrogen isotopes would be available catalysts, are promising methods for the inexhaustibly from the ocean and lithium, a future of hydrogen as a source of energy. common metal, would come from earth’s crust. Power can be supplied from solar cells or The fusion reaction would produce no windmills. However, the storage of hydrogen greenhouse gas and little or a low level of gas poses a big hurdle. It is the lightest gas. radioactive waste. Research and developments, begun four decades ago, show great Metal hydrides, such as Mg2Ni H4, LaNi5H6, might be able to store and release hydrogen developments in Tokamak (Russian word for to fuel motor vehicles. Liquefied hydrogen ether). The machine uses large electromagnetic (below - 241 degree Celsius) or pressurized coils that confine the ionized fuel (plasma) hydrogen gas are other alternative methods within a small chamber as it heats to 100 of storage. Despite lack of technology or million degrees. Thus fusion happens. infrastructure at present, hydrogen energy International thermonuclear research is a promising source of energy future. reactor (ITER) is now in its final phase. It Nuclear Fusion was initiated in the year 1986 by the joint cooperation between European nations, If advances in present day technology India, Japan, China, Russia, South Korea and fail to prevent global warming, humanity must USA. It is being built in southern France and endeavour for a marathon search of new is likely to be completed by 2025. If it technology. Nuclear fusion promises unlimited fuel with comparatively less cost...... To be continued in Page No.-33

Science Horizon 11 DECEMBER, 2020

HARNESSING NUCLEAR ENERGY

Dr. Mridula Mishra The dream of harnessing nuclear energy technological evolution of reliable nuclear started with the discovery of nuclear fission power plants. around 1938-1939 with the work of German Nuclear Fission scientists, Otto Hahn, Fritz Strassmann, Lise Meitner and Otto Frisch. Frisch named the The reaction observed by Hahn and process as nuclear fission by analogy with Strassmann on striking of one thermal neutron biological fission of living cells. In nuclear with a uranium nucleus may be written as: fission a heavy nucleus splits into two (or 235 92 141 n + 92U o 36Kr + 56Ba + 3n + Q sometimes more)smaller nuclei of comparable masses. A large amount of energy In this reaction uranium nucleus splits is liberated in this process because change of into two fragments, known as krypton and mass accompanying the reaction is very barium along with emission of three neutrons. large.The difference of mass appears as energy Here Q is the energy of reaction which can be in accordance with Einstein’s equation E= calculated from the values of masses of mc2. Thus, nuclear fission has been exploited different nuclei. for producing energy which has both peaceful Q = (final masses - initial masses) expressed and destructive use. Both uses are possible in energy units. because nuclear fuels undergo fission when Q = (140.9139+91.8973+3×1.00087- struck by neutrons and in turn emit neutrons 235.0439-1.0087) × 931 MeV= 0.215×931= when they split apart. This makes a self- 200 MeV. sustaining nuclear chain reaction with release of energy at controlled rate in a nuclear reactor, Thus, when one atom of uranium -235 used for generation of electricity or at very undergoes fission, 200 million electron-volts rapid uncontrolled rate in a nuclear or atomic of energy are released. If one gram of naturally bomb. In fact, over the years 1939-45 most occurring uranium, which has about 1019atoms development was focussed on the atomic of uranium -235 undergoes fission, the total bomb. From 1945 attention was given to energy released would be about 200×1019 harness this energy in a controlled manner for MeV= 108 joules. Thus, the 1 kg of uranium naval propulsion and for producing electricity. delivers as much energy as the combustion of Since 1956 the prime focus has been on the 3000 tonnes of coal.

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Almost immediately after the discovery of conditions for producing energy or power. nuclear fission, it was recognised that, because Reactors can be divided roughly into two a neutron can induce fission in a suitable classes, depending on the energy of neutrons nucleus with the emission of additional that sustain the fission chain reaction. These neutrons, a self -sustaining sequence of fission are thermal reactors and fast breeder reactors. is, in principle possible. The condition for Both of them have a supply of fuel usually such a chain reaction depends on the number uranium oxide pellets arranged in tubes to of neutrons. If too few neutrons initiate form fuel rods in reactor core. Periodically fissions, the reaction will slow down and stop, the used-up fuel elements are taken out and if precisely one neutron per fission causes new fuel elements are put in. A thermal reactor another fission, energy will be released at a has a moderator which slows the neutrons and constant rate and if the frequency of fission helps in controlling the fission process. The increases the energy release will be so rapid most commonly used moderators are water, that an explosion will occur. These conditions heavy water and graphite. Control rods are are respectively called as subcritical, critical made of neutron absorbing material such as and supercritical. cadmium or boron which are inserted into the Nuclear Reactor core to control or halt the reaction. When these rods are lowered into the core containing A nuclear reactor is a device in which the fuel elements and the moderator, they absorb nuclear fission is carried out under controlled most of the neutrons and so there can be no

Nuclear Reactor

Science Horizon 13 DECEMBER, 2020 chain reaction. This effectively shuts down and plutonium-239 nucleus and at the same the reactor. As they are pulled out time the non-fissile uranium-238 gets progressively, neutrons are available to split converted to plutonium through neutron uranium, thus releasing more neutrons and capture and radioactive decay. In a thermal larger is the number of fissions in the core and reactor typically only one to two percent of more heat is produced. Another important part the natural uranium is utilised, where as in fast of the system is a coolant, usually ordinary breeder reactor the utilization is increased water which circulates through spaces between sixty to seventy times. In fast breeder reactor, the fuel elements. It absorbs and transmits it is necessary to exclude all materials of low heat from reactor to create steam for turning atomic number which slows down neutrons. the turbines to generate electricity and cools Therefore, water cannot be used as coolant. the reactor core so that it does not reach the Considering the nuclear and heat transfer temperature at which uranium melts (3815 properties of various possible coolants, sodium degree Celsius). Finally, a reactor is encased has been accepted as the coolant for this type in a containment, a big, heavy structure, of reactor. typically several feet thick and made of steel Hazards of Nuclear Reactor and concrete to prevent the escape of any Radioactive waste management is needed radiation from the core, since the uranium in all operations associated with the use of fuel as well as the fission products are nuclear energy. Liquid, solid and gaseous intensely radioactive. radioactive wastes are produced in the mining The nuclear chain reaction in the uranium of ore, production of reactor fuel materials, fuel in a thermal reactor is sustained by slowing reactor operation, processing of irradiated down the neutrons by a moderator. These reactor fuels and numerous related operations. reactors are able to release energy from the The main concern in the safe handling and small proportion of uranium-235 contained in containment of radioactive wastes is the the natural uranium, but unable to use the prevention of radiation damage to humans and uranium-238 which constitutes 99.3 percent the environment by controlling the dispersion of natural uranium. Hence the other type of of radioactive materials. Accidents in nuclear nuclear reactors called as Fast breeder reactors power plants in the past have been attributed are used for this purpose. The significance of mainly to operational errors, design these reactors is that these are able to convert deficiencies and a series of equipment failures. uranium-238 into plutonium-239 in significant However, modern nuclear reactors are quite quantities, so that much more energy can be safe. An individual living near a nuclear power extracted from natural uranium in comparison plant is exposed much less to its emitted to thermal reactors. In these reactors heat is radiation than what one gets from X-rays and produced through the fission of uranium-235 natural sources.The radiation exposure on any

14 Science Horizon DECEMBER, 2020 person living just outside the boundary wall of sea water, this seems to be the fuel for future. a nuclear power plant is between 20 to 50 Despite its tremendous potential there are micro sievert. This is well within the prescribed many technical problems in building a limits of safeguards. (sievert is the SI unit, commercial fusion reactor. with regard to the potential for causing harm Nuclear Energy Today to body cells and tissue) Contrary to what According to latest data, there are around many people fear, a nuclear reactor can never 440 nuclear power reactors in the world, which explode like an atom bomb. Since the total provide about 10% of the world’s electricity. energy developed in reactors at any instant Nuclear energy is the world’s second largest cannot increase suddenly and is very limited source of low-carbon powers. In Indian compared to that of even a small atomic bomb. perspective, nuclear energy is the fifth largest Nuclear Fusion source of electricity after coal, gas, hydro- Nuclear energy can also be harnessed electricity and wind power. India has around from nuclear fusion reactions. It is the reverse 22 nuclear reactors in operation in seven process of fission, where two or more nuclei nuclear power plants with a total installed of light masses fuse together to produce a capacity of 6,780 MW. Apart from generation single nucleus of moderate mass. Here too of electricity, over 50 countries utilise nuclear mass is converted into energy. For example, energy in about 220 research reactors. In fusion of two nuclei of deuterium forms a addition to research, these reactors are also tritium and a hydrogen nucleus while the fusion used for the production of medical and of a deuterium and a tritium nucleus forms a industrial isotopes. helium nucleus with two protons and two Energy is the prime mover of the universe. neutrons. For the above reactions to take place, The demand for energy has been increased the colliding nuclei should have enormous with the growth of human civilization. There is speed. This is made possible by heating the always a hunt for new resources of energy. colliding nuclei to a few hundred million Accordingly harnessing of nuclear energy degrees. But much below this temperature, started with establishing nuclear reactors some the atoms strip of their electrons. Thus, they seventy years ago. But its full potential is yet form a mixture of positively charged ions and to be explored. Over the years, nuclear reactors electrons known as plasma. The fusion of all have been viewed both as miracle and menace. the nuclei in one gram of deuterium, yield „ 100,000 kWh of energy. Whereas, a complete Retired Associate Professor in Physics fission of an equivalent amount of uranium, on B-102, Life Style Green the other hand, gives 25,000 kWh. Further, Apartment, KIIT SQR Bhubaneswar-24 since it is cheaper to extract deuterium from E-mail: [email protected]

Science Horizon 15 DECEMBER, 2020

THERMAL POWER PLANT: THEORY & MECHANISM

Ansuman Dash The discovery of fire, more importantly are shown in the figure 1. The operation of the how to use fire, in early Stone Age eventually plant can be understood with the block diagram led the civilisation to where it stands today. In with arrow mark given in Figure 2. seventeenth century following the invention of steam engine rapid industrial revolution The first task is to process the input or commenced. The steam engine utilized the the raw materials into its usable form. For kinetic energy of steam to run a machine to processing the fuel or the coal it is transported get the work done. The steam is produced by to the coal handling plant from the coal storage heating water with the fire generated by the via conveyor belts. In the coal handling plant burning of coal. With the same principle in a there are mills or pulverisers where, the coal is thermal power station an electrical generator pulverised (i.e. crushed into small pieces) to generates electricity from heat energy. Water increase its surface tension to help rapid is heated, turns into steam and drives combustion without using a large amount of DVWHDPWXUELQH ZKLFK GULYHV DQ HOHFWULFDO excess air. The treatment of raw water which is generator. Additionally, the mechanism also collected directly from the river or a channel is include a condenser system which allows the done in de-mineralized (DM) plant situated steam after it passes through the turbine to inside the power station. DM water prevents DFRQGHQVHUDQGUHF\FOHG EDFNWR WKHZDWHU corrosion of boiler tubes. DM water is fed to form and again utilized in the same process. the boiler drum situated at the top of the boiler This closed loop cycle is known as Rankine by the suction pressure of boiler feed pump (BFP). cycle. The generator generates electricity BFP is the largest power consuming auxiliary in based on the principle of electromagnetic the power plant. For driving the air and the coal induction ie, whenever a magnetic field and a dust into the combustion chamber two types of conductor move relative to one another electric forced draft (FD) fans are engaged. The Primary voltage is developed across the conductor. FD fan takes air from the atmosphere through air pre-heater and then it carries the coal dust from To produce the heat in the plant we need the coal pulverizers to the burners located at the fire for which coal and air are required. The four corners of the boiler wall and inject it into burning of coals takes place inside the boiler. the furnace or the boiler. The Secondary FD fan The main input for the power plant is coal, takes air from the atmosphere and through the water and air and the output is ash, electricity air pre-heater this air is mixed with primary air and flue gas. The various parts and accessories

16 Science Horizon DECEMBER, 2020

Figure-1 flow in the furnace. The coal dust is ignited to Pressure Turbine (LPT) the steam is sent to rapidly burn, forming a large fireball at the centre the condenser for condensing back to water by of the boiler. The temperature in fire ball is of a cooling water system. This condensed water the order of 1300 deg.C. The water inside the is collected in the hot-well situated below the boiler drum is allowed to pass into the condenser and is again sent to the boiler drum suspended boiler tubes, made of iron, attached by the suction pressure of condenser extraction to the inside wall of the boiler and get heated. pump (CEP) and boiler feed pump (BFP) Water is converted to steam in the boiler forming a closed cycle. The CEP draws the tubes and steam is separated from water in the water in hot-well to the deaerators through boiler Drum. The saturated steam from the multiple heaters. In deaerator dissolved gases boiler drum enters the High Pressure Steam including oxygen are removed from the water Turbine (HPT). In the HPT the steam pressure and then the water reaches the suction head of is utilized to rotate the turbine and the resultant the BFP. The HPT, IPT and LPT are on a is the rotational energy. Then through the common shaft with the generator and the Intermediate Pressure Turbine (IPT) and Low rotational energy imparted to the turbines

Science Horizon 17 DECEMBER, 2020

Figure-2 rotates the generator which converts the The hot flue gas generated in the furnace mechanical energy of turbine into electrical is passed through the super-heater, re-heater, energy and delivers the electrical output at economiser, air pre-heater, ESP (Electro static around 14 Kilo Volts (KV) of three phase AC precipitator) and then to the atmosphere (Alternating current) at 50Hz frequency to the through chimney. The suction of the flue gas generator bus bar. This voltage is stepped up to from the furnace to the chimney is done by the 400 KV by Step up transformer and is allowed induced draft fan. The purpose of reheater and to charge the transmission lines at switchyard. superheater is to give further energy to the This electrical power reaches our home through exhaust steam from high pressure turbine and the long transmission lines and distribution to reroute it to the intermediate pressure lines subjected to multiple stages of step turbine. Reheater and superheater gets the down transformers at a final rating voltage of heat from the flue gas. Economiser also three phase 400 Volts AC or single phase 240 recovers heat from the flue gas and utilises Volts AC. this heat to the feed water before it enters the

18 Science Horizon DECEMBER, 2020 boiler drum which improves the overall In thumb rule, one ton of lignite coal is efficiency of the plant. Similarly air pre-heater needed to produce 1 MWh of energy and with extracts the heat from the flue gas and warms better quality of coal 0.5 ton is needed to the atmospheric air which enters the boiler produce the same amount of energy. The through FD fan. From air pre-heater this flue average efficiency of thermal power plant is gases go to ESP in which the dust particles are 35 % only as large amount of energy is lost in ionized and attracted by charged electrodes. the condenser system and flue gas. In India With Hammering process the fly ash comes there are 269 numbers of thermal power plants. down and is collected at the bottom. The fly Vindhyachal Thermal Power Station of Madhya ash is dry and is used in manufacture of cement. Pradesh is the largest power plant in India The burning of coal generates huge amount of with the installed capacity of 4760 MW and ash which is collected at the bottom ash hoper run by NTPC Ltd. In Odisha thermal power situated below the boiler. The bottom ash is plants are situated in Talcher, Kaniha, Darlipali sent to the ash handling plant from where it is and Ib. Thermal power plants have the sent to the ash dyke. advantages like they can respond to rapidly The condensation system uses Cooling changing loads without difficulty and overall water that is circulated through the condenser production cost of power is cheaper than tubes for condensing the steam. This water is others. However the drawbacks are the supplied from a natural source such as river or production of green house gases, channel and by the pressure of cooling water consumption of large amount of water, great pumps it reaches the condenser. The circulating difficulty in ash handling, unavailability of water absorbs heat from the exhaust steam and good quality coals etc. Since the coal based becomes hot. This hot water is discharged to plant is not environment friendly it is high a lake or river. To ensure the availability of time to look into the alternative energy cold water throughout the year, a cooling sources like solar, wind or nuclear. Like any tower is used. Hot water of condenser is other evolution process, the future power passed to the cooling tower where it is generation will depend only on the renewable naturally cooled or draft fans are used for energy and thermal power plant will remain cooling after which it is again fed back to the in history. condenser tubes. Some steam and water are „ lost when it is passed through the different Manager, NTPC Ltd PLOT No. 215, Sisupalgarh component of the system. To make up the Bhubaneswar- 751002 balanced water after the condensation process Mob: 9437565393 Email: [email protected] DM water is fed in parallel to the common header of BFP.

Science Horizon 19 DECEMBER, 2020

HYDROPOWER RESOURCES

Er. Jaya Prakash Chand Hydropower Energy energy (KE), converted to mechanical energy Power is a basic infrastructure required (ME) and at last converted to electrical energy for overall development of the Nation. It is a (EE). necessary input, for economic growth of a So, PE o KE o ME o EE is the Hydropower country. The chief sources of energy to concept. generate electricity are fuel in all forms i.e. Way back in 1882, British – American solid, liquid and gaseous, water, nuclear, solar, engineer, james francis developed the first wind, wave and tide. Hydropower depends on turbine. In India, the first Hydro Power available water head & discharge. Station was commissioned on 10.11.1897 Hydro is a Greek word, meaning water. at Sidrapong near Darjeeling Town of West Greeks used water wheels for grinding wheat Bengal. more than 2000 years ago. Hydropower is the Components of Hydroelectric Plants conversion of mechanical energy to electricity. (HEP) Flowing water creates energy that can be Five major components of HEP are captured and turned into Electricity. This is called Hydropower. (i.) Dam with Penstock and Surge Shaft Hydropower is a renewable, economical, (ii.) Reservoir with Intake Well non-polluting and environmentally benign (iii.) Turbine with Valve and Nozzle source of energy. It starts and stops (iv.) Generator instantaneously. Thus, it is reliable and able to (v.) Switchyard meet peak demand. Hydropower has long useful life and helps in conserving scarce Types of Hydraulic Installation fossil fuels. Based on head, discharge, generation Hydropower plant uses a dam across a capacity, load, operation, turbine and type. It river, creating the reservoir. Water released can be classified as under: from the reservoir through trash rack, intake, a) Head Based - Three types: surge tank, penstock, valve & nozzle, flows (i.) Low Head - Less than 10 m down to a turbine, spinning it, which in turn (ii.) Medium Head - 10 m to 100 m activates a generator, to produce electricity. (iii.) High Head - More than 100 m So, potential energy (PE) converted to kinetic

20 Science Horizon DECEMBER, 2020

(iii.) Pumped Storage: U p p e r pond and Tail pond concept (iv.) Pumps as Turbines (PAT) : Reversible (v.) Hydrokinetic:use of River’s natural fall/Canal fall f)Turbines Based – Four types: (i.) Kaplan: Low head – high discharge, axial flow, less number of blade, twisted blade b) Discharge Based - Three types: (i.) Low Discharge (ii.) Francis: Medium head – medium discharge, radial flow (ii.) Medium Discharge (iii.) High Discharge (iii.) Pelton: High head – low discharge c) Generation Capacity – Nine types: (iv.) Deriaz:Similar to Kaplan, with incline blade, suitable for high variable head (i.) Pico - Less than 5 kW (ii.) Micro - upto 100 kW Advantages of Hydroelectric Project (iii.) Mini - 100 kW to 1 MW (i.) Renewable: Water cycle is endless (iv.) Small - 1MW to 10 MW (ii.) Green: Non-Polluting (water or air) (v.) Medium - 10 MW to 30 MW (iii.) Reliable: Starting and stopping are instantaneous (vi.) Large - More than 30 MW (iv.) Long life: Dam, designed for long life, (vii.) Super - up to 1000 MW hence Power House (viii.) Mega - 1000 MW to 4000 MW (v.) Conservation: helps in conserving scarce (ix.) Ultra-Mega - above 4000 MW fossil fuels d) Load based – Two types: (vi.) Peak Demand: Able to meet peak demand easily (i.) Base Load (vii.) Low cost: Most Hydropower Projects, (ii.) Peak Load being a part of Multipurpose Projects, e) Operation Based – Five types: capital cost is shared, hence low cost. (i.) Run of River : With / without control Cost of hydropower is 50% of nuclear (ii.) Storage : Impoundment power, 40% of fossil fuel and 25 % of gas

Science Horizon 21 DECEMBER, 2020

(viii.)Low Maintenance Cost: Water is main i. Vast submergence with organic life in-put, available plenty as rainfall. Also, ii. Inflow drops sediments, organic matter, man-power for generation & nutrients of agricultural field, provides maintainance is very less. materials for microbes to breakdown (ix.) Flexible: Pairs well with other and convert to methane. requirements of project, though iii. Fluctuation of reservoir water level, sometimes conflicting. methane is released. (x.) Safe: No burning of fossil fuel, no hazard Hydropower Computation of nuclear power The theoretical power (P) available is in Disadvantages of HEP exact proportion to the head (H) and flow (Q). (i.) Facility (Dam & Reservoir) for P = Q x H x c Hydropower is not clean energy: c is a constant. It is the product of density a. Dams and reservoirs are major drivers of water and the acceleration due to gravity of climate change, affecting land use, (g). If P is measured in KW, Q in m3/s and H homes, natural habitats, blocking natural in meter, the gross power of the flow of water course of river, effects fish migration is, and population. P = 1000 x 9.8 x Q x H b. Displaces people (Rehabilitation & This available power is converted by Resettlement). hydro turbine to mechanical power which is c. Civil construction of dam is costly. again converted to electrical power by Project being in hilly area, transmission generator. As there are some losses in turbine line becomes costly. and generator, the net power is: d. Depends on Local Topography suitable P = 1000 x 9.8 x Q x H x n for dam. Where n =efficiency of turbine and e. If rainfall is less in draught years, generator (it is less than 1) reservoir impounding becomes less and Hydropower Scenario in India generation affected. India ranks 5th globally considering f. Conflicting demands in case of installed hydropower capacity. As of Multipurpose Project. 31.09.2020, installed hydropower capacity g. Green house gas emission: Reservoir in India is about 46,000 MW, against emits methane, having environment potential of 148,700 MW. Further, 56 warming effect due to number of pumped storage for 94,000 MW have been identified.

22 Science Horizon DECEMBER, 2020 Hydropower Projects (HPP) in Odisha Sl HPP River Installed Capacity Type of Turbine Year of Remarks No. No. Size of Total commision of Unit capacity Unit (mw) (mw) 1 Macha- Macha- 6 3x17 120 Kaplan 1955 kund kund 3x23 2 Hirakud Mahanadi 7 Unit 1 275.5 Kaplan 1958 *20 MW, Unit 2 220.5 Kaplan 1957 against75 MW, in 2x49.5 Unit 5 & 6, as per Unit 3 Francis 1956 orders of OERC Unit 4 Francis 1957 2x32 Unit5 Kaplan 1962 Unit 6 Kaplan 1963 2x37.5 =75 MW Kaplan 1990 but 20* MW Unit 7: 37.5 3. ChiplimaTail Race 3 3 x 24 72 Kaplan 1962 of Hirakud 1962 Power 1964 House

4. Rengali Brahmani 5 5 x 50 250 Kaplan 1985 1986 1989 1990 1992 5. Balimela Sileru 8 6 x 60 510 Francis 1st Unit 1973 Proposed Balimela 2 x 75 Last unit Pumped Storage 2009 Project (PSP) for 2 x 250 MW=500 MW 6. Upper Kolab 4 4 x 80 320 Francis 1993 Proposed Upper Kolab Kolab PSP 2 x 160 MW = 320 MW Also Proposed to divert excess water of UKP through a 4 km long Tunnel to Balimela 7. Upper Indravati 4 4 x 150 600 Francis 2001 Proposed Upper Indravati Indravati PSP 4 x 150 MW = 600 MW

Science Horizon 23 DECEMBER, 2020 Top Ten Countries (based on Hydropower Installed Capacity): Sl. Country Hydropower Remarks No. Installed Capacity Country’s LargestHydropower Station (MW) 1. China 311,000 22,500 MW:ThreeGorges, across Yangtze River(World No.1) 13,800 MW: Xiluolo (World No.3) 6,400 MW: Xigjiaba (World No.8) 6,300 MW: Longtan(World No.10) 2. U.S.A 10,2000 6,800 MW: Grand Coulee on Columbia River (World No.7) 3. Brazil 89,000 14,000 MW: Itaipu Dam (World No.2) 9,390 MW: Belo Monte (World No.5) 8,370 MW:Tucurui (World No.6) 4. Canada 76,000 5. Russia 51,000 6,400 MW:Sayano- Shushenskaya (World No.9) 6. Japan 50,000 7. India 46,000 1,960 MW (18 units): Koyna HEP across Koyna River (India No.1)1,500 MW:Naptha Jhakri across Satlej(India No.2)1,450 MW: Sardar Sarovar across Narmada (India No.3) 1,325 MW: Bhakra across Satlej(India No.4) 8. Norway 31,000 9. France 25,000 10. Venezuela 15,000 10,200 MW: Guri(World No.4)

Promising Water Power Technology New Hydropower Technology a. Modular Hydropower: Constructed offsite It is Marine and Hydro Kinetic (MHK) and then integrated to existing / new site Technology, capturing energy, from natural b. Powering non-powered Dam motion of Ocean Water, such as Waves and c. Pumped Storage Hydropower: Upper Tides. Pond and Tail Pond „ Retd. Engineer-in-Chief (WR) & Co-Team Leader of d. Tidal Energy by Marine & Hydro Kinetic Nippon Koei India (MHK) for PMC of Rengali Irrigation Project, Phase II, Sukinda e. Wave Energy by MHK 24 Science Horizon DECEMBER, 2020

THE NEED FOR RENEWABLE ENERGY SOURCES

Dr. Sanjeeb Kumar Das Introduction reused by recycling them. But coal, Energy is defined by physicists as the oil/petroleum and natural gas cannot capacity to do work. Energy is found on our be recycled. planet in a variety of forms, some of which are immediately useful to do work, while others require a process of transformation. The sun is the primary source of energy in our lives. Besides, water, fossil fuels such as coal, petroleum products, water, nuclear power plants are sources of energy. Energy has always been closely linked to man’s economic growth and development. Present strategies 2. Renewable resources: It can be for development that have focused on rapid replenished or reproduced easily, at a economic growth have used energy utilization rate comparable or faster than its rate as an index of economic development. This of consumption by humans. Some of index, however, does not take into account them (sunlight, air, wind, tides, the long-term ill effects on society of hydroelectricity) are continuously excessive energy utilization. available and their quantity is not affected With respect to renewability, natural by human consumption. They have also resources may be divided into two types. been named perpetual resources. 1. Non-renewable resources. These are Proper utilization of energy resources formed over long geological periods is a hot debate going these days. It is very (minerals and fossil fuels). Their rate essential to choose which source of energy of formation is extremely slow, so must be used and why. Majority of factors they cannot be replenished once they such as cleanliness, cost, stability, efficiency get depleted. Metallic minerals can be and environmental effects must be taken into

Science Horizon 25 DECEMBER, 2020 account. Fossil fuels will deplete one day and destruction of marble monuments and crops. the industries must turn to renewable sources Coal mining has deprived land of its liveliness as soon as possible. Moreover, these fossil and has made it barren. There are various fuels pose a huge threat to environmental portions of land where crop cannot be grown balance and are a cause of many ecological due to this harmful side effect. Coal mining hazards. has caused many unfortunate deaths in the Fossil Fuel Dilemma past. Fossil fuels are basically compounds of Importance of Renewable Energy hydrocarbons comprising of coal, natural gas The most significant feature of renewable and oil. The main dilemma of fossil fuels is energy is its plentiful supply. It is infinite. not the use of them but the ill side effects Renewable energy sources are hygienic their usage creates. Fossil fuels are not sources of energy that have a much lesser sustainable. It means they will eventually negative environmental impact than deplete. When they are burnt, they produce conventional fossil energy technologies. Most large amounts of harmful gases, the most renewable energy investments are spent on noteworthy being carbon dioxide gas. This gas materials and personnel to build and maintain is the greatest culprit in producing global the facilities, rather than on costly energy warming. This global warming is continuously imports. With technological advancements in playing its negative part in increasing the mass communication, people have now temperature of the planet and endangering the become aware of the demerits of burning lives of species on it. Moreover, due to high fossil fuels. Renewable energy is the need of temperature, ice has been constantly melting the hour. Its clean and sustainable nature has at Arctic and Antarctica which is making the compelled the human beings to think seriously sea levels higher than normal. This can lead to about it. Scientists and engineers, around the floods and can severely affect agricultural and world, are continuously working and fishing activities. Middle East countries have researching in this domain. They are finding huge reserves of coal, oil and natural gas and new ways to use these sources of energy many other countries are dependent on them effectively. Global warming is a huge hazard for invariable supply of these fuels. Burning which is being caused by burning of coal, oil of fossil fuels produce nitrogen monoxide, and natural gas. It is very harmful for the nitrogen dioxide, sulphur dioxide and carbon planet and the living beings on it. Moreover, monoxide gases. These deleterious gases fossil fuels are a cause of many unfortunate directly give birth to air pollution which causes mishaps in the past as described before. To put smog and dilapidation of human health and an end to this apocalypse, we must resort to plant growth. Acid rain, mostly caused by renewable sources. This is because they are sulphur dioxide, leads particularly to the cleaner and do not produce poisonous harmful

26 Science Horizon DECEMBER, 2020 gases. Moreover, fossil fuels are finite. They „ Renewable energy can make the will certainly end one day. Therefore, before electricity prices stable. It is because the crucial stage comes up, experts of energy their cost is dependent only on the initial sectors must maintain a positive attitude in this invested capital and is free of the regard and should try their level best to replace fluctuating costs of coal, oil and natural fossil fuels with renewable energy sources as gas. The daily price of oil depends on the main sources of generating electricity. various factors which also includes „ Renewable energy is dependable and political stability in various regions of the copious and will potentially be very globe. In the past, political discords have cheap, once this technology and its caused severe energy crises. present infrastructure are enhanced. The „ Renewable energy can be locally major sources of renewable energy produced and therefore, it is not include solar, wind, biomass, geothermal, vulnerable to distant political hydropower and tidal energy. Non disturbances. Many of the safety renewable energy, such as coal, natural concerns engulfing fossil fuels, such as gas and oil, require costly explorations explosions on oil platforms and and potentially dangerous mining and collapsing coal mines do not exist with drilling, and they will become more renewable energy. Coal, natural gas and expensive as supplies diminish and oil reserves are restricted and veiled. An energy demand increases. unknown and inadequate amount of each „ Renewable energy produces only small resource is buried deep underground or levels of carbon emissions and therefore, under the ocean. As more of these helps battle climate change caused by reserves are harvested, finding new fossil fuel burning. sources shall become more complicated and more expensive, and utilizing them „ Renewable energy sector is becomes tougher and sometimes risky comparatively new in most countries and as well. this sector can attract a lot of companies to invest in it. This can create a pool of Applications of Renewable Energy new jobs for the unemployed. Therefore, Applications of renewable energy are renewable energy can play a very broadly classified as “on-grid” and “off-grid”. significant role in bringing the A grid is basically an integration of unemployment scale down in many generation, transmission and distribution countries, especially the developing system which supplies energy to several ones. This, in turn, will make a substantial consumers. On-grid and off-grid are the terms difference to their economies. which describe the way electricity is delivered.

Science Horizon 27 DECEMBER, 2020

On-grid deals with power stations which Geothermal energy is most common amongst are directly connected to grids such as wind farmers. They use this energy to heat their farm and solar panels. greenhouses which enable them to grow Off-grid applications, in general, serve various fruits and vegetables all around the only one load, such as a small home or a year. In some countries, the heat produced village house. Off-grid applications can take from this energy is also utilized to heat many forms, from photovoltaic (PV) modules pedestrian walkways and bicycle lanes in order for an individual village home to centralized to prevent them from freezing in extreme windmills to power a village water pump or a winters. Solid biomass can be burnt in commercial battery charging facility. These incinerators to produce heat that can be used off-grid applications are most generally used to produce steam for electricity generation. in remote or rural settings. Biomass can also be converted to bio-fuels like ethanol for transportation needs. A widely A major on-grid application is to generate used application of hydropower is in a electricity in mass amounts. The most compressor. Specially designed compressors important application of wind energy is the can be used for adjusting turbine blades and wind turbine. The wind turbine can convert the governor valves. They can also be used to blow energy in the wind to mechanical power which out the water to eliminate the load during in turn, can be fed into a generator to generate starting. large amounts of electricity. This electricity may be used to charge batteries or pump The Future of Energy water. Wind energy can also be used in wind- Proper use of energy is very vital in powered vehicles. This can save a lot of fuel catering to the need for energy demand. Experts and can provide increased performance and all over the world are of the opinion to utilize efficiency. Similarly, solar energy can be used renewable energy sources for power to power photovoltaic panels which are an generation. Gone are the days when fuel prices excellent way of producing electricity at small were low and power companies resorted to scales, especially for rural and remote areas, fossil fuels for meeting energy demand. The where transmission lines cannot reach. Due to sustainable nature of wind, hydropower, their little maintenance and high reliability, geothermal, solar and biomass highly they are ideal to use in isolated and far-flung encourage the energy supply companies to places. Offices can employ glass PV modules utilize them. Moreover, people can setup small for reliable supply of electricity. Solar energy solar panels over their homes to tackle their is also widely utilized in solar water heaters, own load demands. These sources of energy solar calculators and solar lights. They work are not hazardous to the environment since on the principle of storing energy from the they do not require any sort of mining and sun during the day and utilizing it at night time. drilling and produce nearly no pollution. Most

28 Science Horizon DECEMBER, 2020 importantly, they are much more economical of the importance of using renewable sources than fossil fuels and do not cause adverse of energy but still a lot of work needs to be mishaps. Conservation of energy and utilizing done in this domain. For instance, awareness renewable sources is the ultimate destination programs must be started in various regions of energy. Many vehicles run on gasoline by local engineers and scientists to make (which is a fossil fuel). Gasoline will deplete people responsive of the importance of one day and vehicle industry must resort to alternative energy technologies. They must some new sort of energy such as hybrid systems also discourage them to use fossil fuels due to to continue its business. Energy can be their evident demerits to the environment and conserved in many ways. Many a times, we living beings. Courses on renewable sources take for granted the lights being switched on. must be made compulsory to students at When not in the room, the lights do not need school, college and university levels in order to be switched on. This practice will certainly to make them realize their significance and to save lots of cash on electricity bill. increase their knowledge in this sphere. The Incandescent lamps can be replaced with governments should revise the power policies Compact Fluorescent Lamps (CFLs). They to cope with the energy crisis and to make full consume very less power and give much more use of renewable energy sources. Innovative light using the same amount of current. This solutions must be brought by experts in the not only saves money, but it also conserves an field to solve the energy catastrophe. energy source for others. Air conditioning and Technology exchange programs must be heating are responsible for a large percentage initiated by developed countries in order to of electricity bills in various countries. help the developing countries to establish, Consider adjusting the thermostat of air build and reinforce the renewable energy conditioner and heater by a few degrees, but sector. while still maintaining soothe. For example, if Conclusion the heater is typically set to 71 degree Choosing to use a renewable energy Fahrenheit in the peak winter, set it to, for source will not only translate into cost savings instance, 69 and if the air conditioner is at 73 over the long-term, but will also help protect in the peak summer, set it to, for instance, 75. the environment from the risks of fossil fuel Just a couple of degrees can make a emissions. Energy conservation awareness considerable indentation in the amount of campaigns must be initiated at government energy consumed while this also reduces the level to make people aware of the importance electricity bill. of conserving energy. Moreover, power The Solution companies should gradually resort to the use There is no hesitation in saying that of renewable resources as they are profuse people are becoming increasingly conscious and will never deplete. Social media can play

Science Horizon 29 DECEMBER, 2020 a key role in this by educating people about 2) Kissell E T., Buchla M. D., Floyd L.T. (2017): energy sources and their utilization. Colleges Renewable Energy Systems, Pearson Publication: 1-504. and universities should teach a compulsory 3) Rathore NS, Khobragade C., Asnani B. subject on energy conservation and utilization. (2010): Fundamentals of Renewable Energy Given that these steps are followed accurately, Sources, Himanshu Publications: 1-250. the time is not far when the entire world will 4) Wengenmayr R., Bührke T. (2013): be reliant on renewable sources for power Renewable Energy: Sustainable Concepts for the Energy Change,Wiley online library: 1-164. production because this is the definitive future 5) Mukherjee, D., Chakrabarti, S. (2004): of energy. Fundamentals of Renewable Energy Systems, References New Age International (P) Ltd Publishers: 1- 1) Kaltschmitt M., Streicher,W., Wiese A. 262. (2007):5HQHZDEOH HQHUJ\ 7HFKQRORJ\ „ economics and environment, Springer, Berlin/ Department of Botany, Regional Institute of Education (NCERT), Heidelberg: 1-220. Sachivalaya Marg, Bhubaneswar E-mail: [email protected]/ [email protected] ALL INDIA INSTALLED CAPACITY (in MW) OF POWER STATIONS (As on 31.10.2020) Sl. Types of Power Station Installed Capacity Percentage No. 1) Thermal Power 231,320.72 61.94 i. Coal - 199594.50 MW ii. Lignite - 6260.00 MW iii.Gas - 24956.51 MW iv. Diesel - 509.71 MW 2) Nuclear Power 6,780 1.82 3) Hydropower (>25 MW) 45,699.22 12.24 4) Renewable Energy 89,635.65 24.00 i. Small hydropower - 4740.47 MW ii. Wind Power - 38,263.05 MW iii.Biomass - 10,145.92 MW iv. Waste-to-Energy - 168.64 MW v. Solar Power - 36,317.57 MW TOTAL 373,435.58 100

30 Science Horizon DECEMBER, 2020

SOLAR ENERGY

Satyaranjan Jena Solar energy is the most abundant energy play an important part in the global energy resource on Earth. It can be captured and used future. in several ways, and as a renewable energy There are many ways to use energy from source, is an important part of our clean the sun. The two main ways to use energy from energy future. The sun does more for our the sun are photovoltaics and solar thermal planet than just provide light during the daytime capture. – each particle of sunlight (called a photon) Photovoltaic System that reaches Earth contains energy that fuels our planet. Solar energy is the ultimate source Photovoltaics are much more common responsible for all of our weather systems and for smaller-scale electricity projects (like energy sources on Earth, and enough solar residential solar panel installations), and solar radiation hits the surface of the planet each thermal capture is typically only used for hour to theoretically fill our global energy electricity production on massive scales in needs for nearly an entire year. utility solar installations. In addition to producing electricity, lower temperature Where does all of this energy come variations of solar thermal projects can be from? Our sun, like any star in the galaxy, is used for heating and cooling. like a massive nuclear reactor. Deep in the Sun’s core, nuclear fusion reactions produce Solar is one of the fastest growing and massive amounts of energy that radiates cheapest sources of power in the world, and outward from the Sun’s surface and into space will continue to spread rapidly in the coming in the form of light and heat. years. With solar panel technology improving each year, the economic benefits of solar Solar power can be harnessed and improve, adding to the environmental perks converted to usable energy using photovoltaics of choosing a clean, renewable energy source. or solar thermal collectors. Although solar energy only accounts for a small amount of A common way for property owners to overall global energy use, the falling cost of take advantage of solar energy is with a installing solar panels means that more and photovoltaic (PV) solar system. With a solar more people in more places can take PV system, solar panels convert sunlight advantage of solar energy. Solar is a clean, directly into electricity that can be used renewable energy resource, and figures to immediately, stored in a solar battery, or sent

Science Horizon 31 DECEMBER, 2020 to the electric grid for credits on your for heating and cooling; mid-temperature, used electric bill. for heating water; and high-temperature, used for electrical power generation. Solar panels convert solar energy into usable electricity through a process known as (i) Low-temperature solar thermal energy WKHSKRWRYROWDLF HIIHFW ,QFRPLQJ VXQOLJKW systems involve heating and cooling air strikes a semiconductor material (typically as a means of climate control. An example silicon) and knocks electrons loose, setting of this type of solar energy usage is them in motion and generating an electric LQSDVVLYH VRODU EXLOGLQJ GHVLJQ ,Q current that can be captured with wiring. This properties built for passive solar energy current is known as direct current (DC) use, the sun’s rays are allowed into a electricity and must be converted to alternating living space to heat an area and blocked current (AC) electricity using a solar inverter. when the area needs to be cooled. This conversion is necessary because the Indian (ii) Mid-temperature solar thermal energy electric grid operates using AC electricity, as systems include solar hot water heating do most household electric appliances. systems. In a solar hot water setup, heat Solar energy can be captured at many from the sun is captured by collectors on scales using photovoltaics, and installing solar your rooftop. This heat is then transferred panels is a smart way to save money on your to the water running through your home’s electric bill while reducing your dependence piping so you don’t have to rely on on nonrenewable fossil fuels. Large companies traditional water heating methods, such and electric utilities can also benefit from as water heaters powered with oil or gas. photovoltaic solar energy generation by (iii) High-temperature solar thermal energy installing large solar arrays that can power systems are used for generating company operations or supply energy to the electricity on a larger scale. In a solar electric grid. thermal electricity plant, mirrors focus Solar Thermal Power the sun’s rays on tubes containing a liquid that can hold heat energy well. This heated A second way to use solar energy is to fluid can then be used to turn water into capture the heat from solar radiation directly steam, which then can turn a turbine and and use that heat in a variety of ways. Solar generate electricity. This type of thermal energy has a broader range of uses than technology is often referred to a photovoltaic system, but using solar thermal energy for electricity generation at small scales DVFRQFHQWUDWHGVRODUSRZHU is not as practical as using photovoltaics. Advantages of Solar Power There are three general types of solar ² Solar energy is an immaculate and thermal energy used: low-temperature, used renewable energy source

32 Science Horizon DECEMBER, 2020

² Once a solar panel is installed, solar photovoltaic panels require inverters as energy can be produced free of charge. well as storage batteries, increasing the

² Solar energy will last forever while it is initial investment for solar power estimated that the world’s oil supply will accordingly. run out in 30 or 40 years. i In the case of land-mounted PV panels, ² Solar energy causes no pollution. moderately large areas are needed; more often than not, land is available for this ² Solar cells create no negative impact at use for only 15-20 years. all. On the other hand, the giant machines that pump oil are noisy polluters, and i Solar panel efficiency is generally low therefore very unfeasible (between 14%-25%), in contrast to the higher effectiveness of other renewable ² Almost no maintenance is required to energy systems. keep solar cells running. There are no moving parts in solar cells, making it i In spite of the fact that PV panels require difficult to harm them. no excessive maintenance or operating costs, they are fragile and can be damaged ² In the long term, there can be a high easily; extra insurance costs are therefore return on an initial investment because essential to protect a PV investment. of the amount of free energy a solar „ panel can produce; it is estimated that Asst. Professor, School of Electrical Engineering, the normal family can generate half of KIIT Deemed-to-be University, Bhubaneswar-751024 its energy from solar panels. Disadvantages of Solar Energy i As with all renewable energy sources, ...... Continuing from Page No.-11 solar energy has regularity issues; the sustains energy generation over a long period, sun does not shine at night, and during a Sun will be created on the surface of the the day there may be clouds or rain. Earth to shine on humanity. i Therefore the intermittency and Acknowledgement: I thank my grand idiosyncrasies of solar energy make solar nephew Er. Kali Prasad Samantaray for panels a less reliable solution. his constant help throughout the period of i Solar panels require additional preparation of this manuscript. equipment, like inverters, to convert „ direct power (DC) to alternating current Vill. /P.O. Gopapur, Dist: Cuttack- 754 031 (AC) for use on the power network. Email: [email protected] i For a constant supply of electric power, particularly for on-grid connections,

Science Horizon 33 DECEMBER, 2020 WIND ENERGY 1Subhendu Kumar Santra 2Dr. Banishree Mishra Introduction solar power are being strongly encouraged. The wind is a free, clean, and inexhaustible Wind power may become a major source of source of energy. It has served mankind well energy in spite of slightly higher costs than for many centuries by propelling ships and coal or nuclear power because of the basically driving wind turbines to grind grain and pump non-economic or political problems of coal water. Many people think there is enough coal and nuclear power. This is not to say that wind for several centuries at present rates of power will always be more expensive than coal consumption, and likewise for nuclear energy or nuclear power, because considerable after the breeder reactor is fully developed. progress is being made in making wind power These are proven resources in the sense that less expensive. But even without a clear cost the technology is highly developed, and large advantage, wind power may become truly coal and nuclear powered electrical generating important in the world energy picture. plants are in operation and are delivering Wind Electric Power Generation substantial blocks of energy to the consumer. The worldwide total cumulative installed Unfortunately, both coal and nuclear present electricity generation capacity from wind serious environmental problems. Coal requires SRZHUKDVLQFUHDVHGUDSLGO\VLQFHWKHVWDUWRI large scale mining operations, leaving land the third millennium, and as of the end of that is difficult or impossible to restore to 2019, it amounts to 651 GW. At the end of usefulness in many cases. The combustion of 2015, China had 145 GW of wind power coal may upset the planet’s heat balance. The installed. In 2015, China installed close to production of carbon dioxide and sulfur dioxide half the world’s added wind power capacity. may affect the atmosphere and the ability of However, as of 2019, wind provided only 5% the planet to produce food for its people. Coal of China’s power. Wind power is used on a is also a valuable petrochemical feedstock and commercial basis in more than half of all the many consider the burning of it as a boiler fuel countries of the world. By 2018, several to be foolish. Nuclear energy has several countries have achieved high levels of wind advantages over coal in that no carbon dioxide power penetration, such as 41% of stationary or sulfur dioxide are produced, mining electricity production in Denmark, 28% operations are smaller scale, and it has no other LQ,UHODQG  LQ3RUWXJDO  major use besides supplying heat. The major LQ*HUPDQ\DQGLQ6SDLQ,Q1RYHPEHU difficulty is the problem of waste disposal, 2018 wind power generation in Scotland was which, because of the fears of many, will higher than the country’s electricity probably never have a truly satisfying solution. consumption during the month. Wind power’s Because of these problems, wind power and

34 Science Horizon DECEMBER, 2020 share of worldwide electricity usage at the spread across the Southern, Western and end of 2018 was 4.8%, up from 3.1% four Northern regions. (Data: Ministry of New and years earlier. In Europe, its share of power Renewable Energy, GoI& Global wind generation capacity was 18.8% in 2018. In statistics 2017) Odisha, a coastal state has 2018, global wind power capacity increased KLJKHUSRWHQWLDOIRUZLQGHQHUJ\2GLVKDKDVD by 51 GW to 591 GW, an increase of 9.6% wind power potential of 1700 MW. The compared to the end of 2017 [Global Wind Government of Odisha is actively pursuing to Energy Council].Wind power generation ERRVW:LQG SRZHU JHQHUDWLRQLQ WKH VWDWH capacity in India has significantly increased in (Data:”Wind power and solar energy in recent years. As of 31 October 2020 the total Odisha”. REVE.) installed wind power capacity was 38.263 GW, Wind Energy Worldwide WKHIRXUWKODUJHVWLQVWDOOHGZLQGSRZHUFDSDFLW\ Global Wind Power Cumulative Capacity in the world.Wind power capacity is mainly (Data: GWEC) [1] [2]

Figure 1. Global Wind Power Cumulative Capacity (Data: GWEC)

Science Horizon 35 DECEMBER, 2020

Distribution of installed wind energy capacity worldwide (Data:Global Wind Energy Council) Top 10 countries by added wind capacity in 2018 [3] [4]

Top 10 countries by cumulative wind capacity in 2019 [5]

W Figure 2.Global Wind Energy Scenario Wind Energy 2.Global Figure

36 Science Horizon DECEMBER, 2020

Power in a Wind Stream kinetic energy into shaft mechanical energy. Thus the value of C is limited to Betz limit. A wind stream has total power given by p For a well-designed turbine the efficiency lies 2 Pt = 0.5m.Vi in the range of 35-45 %. Where, m = mass flow rate of air, kg/s Wind Turbine

Vi = incoming wind velocity, m/s A wind turbine is a rotating machine Air mass flow rate is given by which converts the kinetic energy of wind into mechanical energy. If the mechanical energy m = U AVVi is then converted to electricity, the machine is Where, U = Density of incoming wind, kg/m2 called a wind generator or wind turbine. = 1.226 kg/m2 at 1 atm, 15oC Wind turbines can be separated into two A = Cross-sectional area of wind stream, m2 types based by the axis in which the turbine Substituting the above and accounting for the rotates as Horizontal Axis Wind Turbines and constants, we arrive at the following: Vertical Axis Wind Turbines. The former are 23 more commonly used due to several inherent PW= 0.5 US RVCwp advantages, the latter being used in small scale. Where, Wind Turbine Generator Units P = extracted power from the wind, w Turbine subsystems include: U = air density, (approximately 1.2 kg/m3 at 20oC at sea level) i Rotors which convert wind energy into mechanical energy of the shaft; R = blade radius (in m), (it varies between 40- 60 m) i Nacelle (enclosure) which contains all the conversion equipment, generator, V = wind velocity (m/s) (velocity can be w gear shaft etc. controlled between 3 to 30 m/s) i Tower, to increase the height of the C = the power coefficient which is a function p turbine systems so that higher wind of both tip speed ratio (ë), and blade pitch speeds are captured. angle, (â) (deg.) i Control equipment, Cables and other Power coefficient (Cp) is defined as the civil works. ratio of the output power produced to the power available in the wind. Horizontal Axis Wind Turbine (HAWT) Betz Limit Horizontal-axis wind turbines get their name from the fact that their axis of rotation Betz limit is the theoretical limit assigned to is horizontal. They have the main rotor shaft efficiency of a wind turbine. It states that no and electrical generator at the top of a tower, turbine can convert more than 59.3 % of wind and are pointed into the wind. The variability

Science Horizon 37 DECEMBER, 2020 of wind distribution and speed brings up the Vertical Axis Wind Turbine (VAWT) requirement of a gear system connected to the Vertical-axis wind turbines have the main rotor and the generator. The gear system enables rotor shaft arranged vertically as the plane of a constant speed of rotation to the generator rotation is vertical. Blades are also vertical in thus enabling constant frequency generation. this arrangement. The biggest advantage of Turbine blades are made stiff in order to prevent VAWTs is that they don’t require a yaw control the blades from being pushed into the tower mechanism to be pointed into the wind. Thus by high winds. Downwind machines have also these are useful in sites where wind direction is been built, as they no longer require a yaw random or there is presence of large obstacles mechanism to keep them facing the wind, and like trees, houses etc. Also VAWTs don’t require also because in high winds the blades can turn a tower structure and can be placed nearby a out of the wind thereby increasing drag and ground enabling access to electrical coming to a stop. Most of the HAWTs are components. Some drawbacks are the low upwind as downwind systems cause regular efficiency of wind production and the fact that turbulence which may lead to fatigue. The large drag is created for rotating the blades in detail components of HAWT is provided in a vertical axis.The detail components of VAWT Figure. 3. in provided in Figure. 3. Figure-3

38 Science Horizon DECEMBER, 2020

Figure 4. Internal Components of a Wind Turbine

Internal Components of a Wind Turbine 4. Controller: This is the most important The internal components of a wind turbine are part of the turbine as it controls shown in Figure 4. They are: everything from power output to pitch angle. The controller senses wind speed, 1. Anemometer: This device is used for wind direction, shaft speed and torque at measurement of speed of wind. The wind one or more points. Also the temperature speed is also fed to the controller as it is of generator and power output produced one of the variables for controlling pitch is sensed. angle and yaw. 5. Gear box: This steps-up or steps down 2. Blades: These are aerodynamically the speed of turbine and with suitable designed structures such that when wind coupling transmits rotating mechanical flows over them they are lifted as in energy at a suitable speed to the airplane wings. The blades are also generator. Typically a gear box system slightly turned for greater aerodynamic steps up rotation speed from 50 - 60 rpm efficiency. to 1200 - 1500 rpm 3. Brake: This is either a mechanical, 6. Generator: This can be a synchronous electrical or hydraulic brake used for or asynchronous AC machine producing stopping the turbine in high wind conditions. power at 50Hz

Science Horizon 39 DECEMBER, 2020

7. High-speed shaft: Its function is to drive wind, then the yaw drive rotates the the generator. turbine in the wind direction 8. Low-speed shaft: The rotor turns the 16. Yaw motor: Powers the yaw drive. low-speed shaft at about 30 to 60 Working of Wind Turbine rotations per minute. When the wind strikes the rotor blades, 9. Nacelle: The nacelle is the housing blades start rotating. The turbine rotor is structure for high speed shaft, low speed connected to a high-speed gearbox. Gearbox shaft, gear box, generator, converter transforms the rotor rotation from low speed equipment etc. It is located atop the tower to high speed. The high-speed shaft from the structure mostly in the shadow of the gearbox is coupled with the rotor of the blades. generator and hence the electrical generator 10. Pitch: This is basically the angle the runs at a higher speed. An exciter is needed to blades make with the wind. Changing the give the required excitation to the magnetic pitch angle changes weather the blades coil of the generator field system so that it turn in or turn out of the wind stream. can generate the required electricity. The 11. Rotor: The hub and the blades together generated voltage at output terminals of the compose the rotor. alternator is proportional to both the speed 12. Tower: Towers are basically made up of and field flux of the alternator. The speed is tubular steel or steel lattice. Taller the governed by wind power which is out of control. towers greater is the amount of power Hence to maintain uniformity of the output generated as the wind speed generally power from the alternator, excitation must be goes on increasing with height. controlled according to the availability of natural wind power. The exciter current is controlled 13. Wind direction: Generally erratic in by a turbine controller which senses the wind nature, hence the rotor is made to face speed. Then output voltage of electrical into the wind by means of control generator (alternator) is given to a rectifier systems. where the alternator output gets rectified to 14. Wind vane: Basically it does the job of DC. Then this rectified DC output is given to a wind sensor, measuring the wind speed line converter unit to convert it into stabilized and communicating the same to the yaw AC output which is ultimately fed to either drive, so as to turn the turbine into the electrical transmission network or transmission wind flow direction. grid with the help of step up transformer. An 15. Yaw drive: This drive controls the extra unit is used to give the power to internal orientation of the blades towards the auxiliaries of wind turbine (like motor, battery wind. In case the turbine is out of the etc.), this is called Internal Supply Unit.

40 Science Horizon DECEMBER, 2020

Advantages of Wind Energy 2. “51.3 GW of global wind capacity installed in ´*OREDO:LQG (QHUJ\ &RXQFLO 1. Eco friendly 5HWULHYHG-DQXDU\ 2. Efficient source of renewable energy. 3. “GWEC Global Wind Report ´ 3') *OREDO:LQG(QHUJ\&RXQFLO 3. No recurring expenses for production April 2019. pp. 25, 28. of electricity 4. “Wind energy in Europe in Limitations of Wind Energy ´ 3') :LQG(XURSH  )HEUXDU\ 2019. p. 10. 1. Wind energy farms need large area of 5. “Global wind statistics”. Wind Energy land International. 19 March 2020. Retrieved 13 2. Difficulty in getting regular wind speed -XQH of 15-20 km/h. 6. http://resourceirena.irena.org/gateway/ dashboard/?topic=4&subTopic=18 3. Initial cost of establishing wind energy „ 1 farm is very high. Asst. Professor, School of Electrical Engineering, 4. High level of maintenance of blades of KIIT Deemed-to-be University, Bhubaneswar-751024 E-mail: [email protected] wind mill. 2Asst. Professor, School of Electrical Engineering, Conclusion KIIT Deemed-to-be University, Bhubaneswar-751024 The potential of wind power generation E-mail: [email protected] is immense. Wind, a historical source of State-wise Wind Power Installed energy can be used both as a source of Capacity (in MW) as on 31.03.2020 electricity and for irrigation and agricultural uses. In today’s world, where a greener source State Installed Capacity of energy is the need of the hour, wind energy Tamil Nadu 9304.33 is a promising resource, waiting to be Karnataka 4790.6 harnessed to its true potential. The study of Maharashtra 5000.38 wind turbine and its characteristics showed how Rajasthan 4299.65 it can be properly designed and used to get the maximum output, even with the variable wind Andhra Pradesh 4092.5 speeds. The development of offshore wind Madhya Pradesh 2519.9 farms, which have both a better energy density Kerala 62.9 and lesser interference with the local systems, Gujarat 7541.5 is a definite step forward in realization of the wind potential. Telangana 128.1 References Others 4.3 1. “Global Wind Report 2018”. Global Wind Total 37744.16 Energy Council. Retrieved 20 January 2002.

Science Horizon 41 DECEMBER, 2020 WASTE TO ENERGY: AN ECOFRIENDLY AND EFFECTIVE MUNICIPAL SOLID WASTE MANAGEMENT STRATEGY

Prof. Pramod Chandra Mishra Indian cities presently generate about 90 Most WtE processes generate electricity and/ million tons of solid wastes annually as a by- or heat directly through combustion, or product of industrial, mining, agricultural , produce a combustible fuel commodity, such municipal and other processes. The quantity DVPHWKDQH PHWKDQRO HWKDQRO RUV\QWKHWLF of Municipal Solid Wastes (MSW) the cities fuels. The leading innovative mechanism of generate is eight times more than what it was waste disposal being adopted in India includes in 1947 with a per capita increase of 1- composting (aerobic composting and vermi- 1.33% annually. This increase amount of composting) and waste-to-energy (WtE) mixed household waste has become a national (incineration, pelletisation, biomethanation) problem in India causing severe is a relatively new concept in India. environmental problems. Studies reveal that Incineration about 90% of MSW is disposed of Incineration is the process of control unscientifically in open dumps and landfills and complete combustion for burning solid creating problems to public health and the wastes. It leads to energy recovery and environment. Waste-to-energy (WtE) or destruction of toxic wastes, for example, waste energy-from-waste (EfW) is the process of from hospitals. The method of incineration to generating energy in the form of electricity convert municipal solid waste (MSW) is a DQGRUKHDWIURP WKH SULPDU\ WUHDWPHQW relatively old method of WtE generation. RIZDVWH RU WKH SURFHVVLQJ RI ZDVWH LQWR D Incineration generally entails burning waste fuel source. WtE is a form of energy recovery. (residual MSW, commercial, industrial and

Garbage dumps

42 Science Horizon DECEMBER, 2020

RDF) to boil water which powers steam Delhi was JHQHUDWRUVWKDWJHQHUDWHHOHFWULFHQHUJ\DQG forced to heat to be used in homes, businesses, shut down institutions and industries. One problem the plant due associated is the potential for pollutants to to its poor enter the atmosphere with the flue gases from performance. the boiler. These pollutants can be acidic and Another in the 1980s were reported to cause incineration environmental degradation by turning rain plant was LQWRDFLGUDLQ0RGHUQLQFLQHUDWRUVLQFRUSRUDWH constructed carefully engineered primary and secondary at BARC, burn chambers, and controlled burners waste incinerator medical kg/hr 40 A Trombay designed to burn completely with the lowest (near possible emissions, eliminating, in some cases, Mumbai) for burning only the institutional waste, the need for lime scrubbers and electro-static which includes mostly paper and it is working precipitators on smoke stacks. successfully till date. In many cities, small The temperature in the incinerators varies incinerators are used for burning hospital waste. between 980 and 2000 oC. One of the most attractive features of the incineration process is that it can be used to reduce the original volume of combustible solid waste by 80– 90%. In some newer incinerators designed to operate at temperatures high enough to produce a molten material, it may be possible to reduce the volume to about 5% or even less. Unfortunately, in Indian cities, incineration is not very much practiced. This may be due to the high organic material (40–60%), high moisture content (40–60%), high inert content (30–50%) and low calorific value content (800–1100 kcal/kg) in MSW. The first large- A Pyrolysis machine scale MSW incineration plant was constructed Gasification Technology at Timarpur, New Delhi in 1987 with a capacity of 300 t / day and a cost of Rs. 250 million Gasification, specifically, is a process (US$5.7 million) by Miljotecknik volunteer, that changes a carbon-based material such as Denmark. The plant was out of operation after biomass or MSW into other forms of energy 6 months and the Municipal Corporation of without actually burning it. It converts waste Science Horizon 43 DECEMBER, 2020 materials into a gas via a chemical reaction. generation. The second unit is the TERI The reaction combines carbon-based materials gasification unit installed at Gaul Pahari with little amounts of oxygen and break them campus, New Delhi by Tata Energy Research down into simple molecules. The end result is Institute (TERI). that we will have a mixture of carbon Refuse Derived Fuel (RDF) Plants monoxide and hydrogen. Gasification converts RDF consists largely of combustible about 80% of the chemical energy in the components of such waste, as non recyclable waste fuel into chemical energy in the gas SODVWLFV QRWLQFOXGLQJ39& SDSHUFDUGERDUG phase, so it is a pretty effective method. Air labels, and other corrugated materials. These gasification is more commonly seen than fractions are separated by different processing oxygen gasification. Air gasification has a steps, such as screening, air classification, 3 heating value of 4-6 MJ/m ZKLOH R[\JHQ ballistic separation, separation of ferrous and gasification has heating value of 10-18 MJ/ non-ferrous materials, glass, stones and other 3 m . However, oxygen gasification requires foreign materials and shredding into a uniform oxygen supply which can be expensive. Thus, grain size, or also pelletized in order to produce incineration of solid waste under oxygen a homogeneous material which can be used as deficient conditions is called gasification. The substitute for fossil fuels in e.g. cement plants, objective of gasification has generally been to lime plants, coal fired power plants or produce fuel gas, which would be stored and DVUHGXFWLRQDJHQWLQVWHHOIXUQDFHV5')FDQ used when required. In India, there are few be also further specified into e.g. tyre derived gasifiers in operation, but they are mostly for IXHOV 7')  IURP XVHG W\UHV RU VROLG burning of biomass such as agro-residues, recovered fuels (SRF). The main purpose of sawmill dust, and forest wastes. Gasification the refuse derived fuel (RDF) method is to can also be used for MSW treatment after produce an improved solid fuel or pellets drying, removing the inerts and shredding for from MSW. In India, many RDF plants are in size reduction. operation at Hyderabad, Guntur and Vijaywada Two different designs of gasifiers exist in Andhra Pradesh State. The Hyderabad RDF in India. The first one (NERIFIER gasification plant was commissioned in 1999 near the unit) is installed at Nohar, Hanungarh, Rajasthan Golconda dumping ground with a 1000 t/day by Narvreet Energy Research and Information capacity (but receiving only 700 t/day at (NERI) for the burning of agro-wastes, sawmill present).The RDF production is about 210 dust, and forest wastes. The waste-feeding t/day as fluff and pellets, and it is going to be rate is about 50–150 kg/h and its efficiency used for producing power (about 6.6 MW). about 70–80%. About 25% of the fuel gas The RDF plant at Deonar, Mumbai was set up produced may be recycled back into the system in the early 1990s for processing garbage into to support the gasification process, and the fuel pellets. It is based on indigenous remaining is recovered and used for power technology. However, the plant has not been in 44 Science Horizon DECEMBER, 2020 operation for the last few years and it is owned is not possible through biochemical or by Excel India at present. A similar project has thermochemical technological routes. been established in Bangalore and has had However, there is an urgent need to develop regular production of fuel pellets since facilities to treat and dispose of increasing October, 1989, compacting 50 t/day of garbage, amounts of MSW. More than 90% of waste in converting into 5 t of fuel pellets, which can India is believed to be dumped in an be designed both for industrial and domestic unsatisfactory manner. It is a major problem uses. Gasification–combustion seems to be for many urban local bodies (ULBs) in India, promising as it can reduce pollution and where urbanization, industrialization and increase heat recovery. RDF is another economic growth have resulted in increased promising technology, which is going to be municipal solid waste (MSW) generation per used for producing power. In addition, the person . Effective SWM is a major challenge RDF plant reduces the pressure on landfills. in cities with high population density. Combustion of the RDF from MSW is Achieving sustainable development within a technically sound and is capable of generating country experiencing rapid population growth power. RDF may be fired along with the and improvements in living standards is made conventional fuels like coal without any ill more difficult in India because it is a diverse effects for generating heat. Operation of the country with many different religious groups, thermal treatment systems involves not only cultures and traditions. Depending on the size higher cost, but also a relatively higher degree of the population, composition of waste, and of expertise. products to be obtained (energy or chemical), Conclusion more than one technology can be combined Solid Waste Management (SWM) is at for a better energy usage of waste. The a critical stage of development in India. In biological route is an interesting alternative recent decades, there has been increasing for the utilization of the organic fraction of pressure on developed countries to reduce MSW, as aerobic or anaerobic processes enable their waste associated with single-use the production of biogas and of a compound discarded materials. The objective is to that can be utilized as a fertilizer. Thus there is conserve natural resources, including energy an urgent need to move to more sustainable (which is utilized for the production of such SWM, and this requires new management materials), and reduce the amount of materials systems and waste management facilities. disposed in sanitary landfills. The philosophy Current SWM systems are inefficient, with of waste management aims at decreasing the waste having a negative impact on public health, amount of waste generated by society and the environment and the economy. incentivizing reutilization and recovery of its „ President, Odisha Bigyan Academy, energy content, when reutilization or recycling Bhubaneswar

Science Horizon 45 DECEMBER, 2020 ENERGY FROM SEA 1Dr. Arjyadhara Pradhan 2Dr. Babita Panda Energy is the most basic input for Ocean Thermal Energy Conversion (OTEC) economic growth and development of a OTEC is based on the idea that if we country. Energy consumption is accelerated, actually look at the temperature of the ocean with the development of human living standard. from the surface down deeper, we will find In the year 1973, OPEC (Organization of that there is warm water at the top and it is Petrol Exporting Countries) increased the price about 25°C. Then when we go much deeper we of the oil in fourfold, which was the cause of can get cold water which may only be about severe energy crisis in the world. Government 5°C. So, there is a 20°C difference of of all countries took this matter seriously and temperature that is readily available to us in a need for developing alternative source was large quantities. So, by running a heat engine felt. Another cause of moving towards the based on this temperature difference electricity renewable energy is the concern for the can be generated. That’s basically the idea environment due to ever increasing use of fossil here. fuel and rapid depletion of natural resources The French physicist Jacques-Arsene which led to the development of alternative d’Arsonval first proposed an OTEC system in sources which are environmental friendly. 1881, using a heat engine working on the The renewable energy simply means we Rankine cycle. His student Georges Claude can renew the source of energy or nature built the first OTEC plant in Cuba in 1930. A automatically renews the source of energy. number of variants of OTEC plant are possible, The fact that it can be renewed in a timeframe including closed cycle, open cycle; floating, or in a time scale that is in line with the rate at land based, shelf/tower based, or ‘grazing’; for which we are using it. This is also called as generating electricity, for aquaculture, for clean energy. When we say something is clean desalination processes, or for combinations that means it is clean with respect to the of these. Within the floating variant a number environment which means we already have a of options are available, including ship-shape certain environment around us which has a hull, semi-submersible, submersible, guyed certain distribution of gases, a certain tower, and possibly others. distribution of a temperature and heat and so Advantages on. With the use of clean energy , we are not changing the composition of the atmosphere. i OTEC makes use of renewable, clean, natural resources. Fossil fuels are We have three different sources of replaced by warm surface seawater and renewable energy from the sea such as, (a) cold water from deep sea to generate Tidal Energy, (b) OTEC and (c) Wave Energy. electricity.

46 Science Horizon DECEMBER, 2020 i OTEC can also support numerous spin- Disadvantage off industries. Chilled water that has i OTEC requires expensive, large-diameter already been used can be pumped out of pipes submerged about a mile below the the plant and used in air conditioning, ocean’s surface. industrial cooling and chill-soil i Many of the countries within the viable agriculture (where pipes containing geographical belt (between the Tropic of chilled water are used to chill soil so it Cancer and Tropic of Capricorn) lack the economic resources to build this infrastructure. i Political interference, consequently, jurisdictional conflicts could arise based on international boundary disputes between nations. Tidal Energy Tide is periodic rise and fall of the water level of the sea. Tides occur due to the attraction of seawater by the moon and sun. These tides can be used to produce electrical power which is known as tidal power.When the water is above the mean sea level, it is called flood tide and when the level is below the mean level, it is called ebb tide. A dam is constructed in such a way that a basin gets separated from the sea and a Ocean Energy Thermal Conversion System difference in the water level is obtained between the basin and sea. The constructed can support temperate crops in tropical basin is filled during high tide and emptied climates). during low tide passing through sluices and i Electric power generated by OTEC could turbine respectively. The potential energy of be used to produce hydrogen the water stored in the basin is used to drive i Desalinized water can be produced the turbine which in turn generates electricity through OTEC systems by implementing as it is directly coupled to an alternator. surface condensers to turn evaporated Though the idea of utilizing tides for seawater into potable (fresh) water. human service relates to eleventh century when

Science Horizon 47 DECEMBER, 2020 tidal mills were used in England, the use of tidal power for electric power generation is hardly a decade old as the world’s first Rance tidal power plant of 240 MW capacity in France was commissioned by President de Gaulle in 1965 who described it a magnificent achievement in the human life. The tidal power plants are generally classified on the basis of the number of basins used for the power generation. They are further subdivided as one-way or two-way system as per the cycle of operation for power generation. The largest tidal project in the world is the Sihwa Lake Tidal Power Station in South Korea, with an installed capacity of Tidal Power Plant Scheme 254 MW. Advantages of Tidal Energy „ Tidal power is a known green energy source, at least in terms of emitting zero greenhouse gases. It also doesn’t take up that much space. „ Another benefit of tidal power is that it is predictable. The gravitational forces of celestial bodies are not going to stop anytime soon. Furthermore, as high and low tide is cyclical, it is far easier for engineers to design efficient systems, than say, predicting when the wind will blow or when the sun will shine.

Tide Formation 48 Science Horizon DECEMBER, 2020

„ Tidal power plants can last much longer flex where segments are connected. This than wind or solar farms, at around four connection is then connected to hydraulic times the longevity. Tidal barrages are pumps which convert the energy. long concrete structures usually built Oscillation Water Columns (OWC) is a across river estuaries. partially submerged enclosed structure. The Disadvantages of Tidal Energy upper part of the structure, above the water, is „ Lack of Research filled with air and incoming waves are funneled into the bottom part of the structure. When „ Electro-magnetic emissions might also these waves come through the structure it causes disrupt the sensitive marine life the water column to rise and fall with the wave „ High construction cost which causes the air in the top structure to „ Alteration of currents and waves. pressurize and depressurize. This in turn pushes Wave Power and pulls air through a connected air turbine at Wave energy (or wave power) is the the top of the structure, converting the energy. transport and capture of energy by ocean Overtopping has a wave lift over a barrier surface waves. The energy captured is then which fills a reservoir with the water and is used for all different kinds of useful work, then drained through a hydro turbine. This including electricity generation, water technology is very similar to a conventional desalination and pumping of water. hydropower dam. The first patent in wave energy happened Inverted-Pendulum device uses the motion in Paris in 1799. Monsieur Girard and his son of waves to move a hinged paddle back and forth. proposed using direct mechanical action to The motion of the paddle drives hydraulic pumps drive heavy machinery, including mills, saws, which drives electrical generators. and pumps. The world’s first operational wave There are five main types of technology SRZHUJHQHUDWRULV ORFDWHG RII WKH FRDVW RI used including; Absorbers, Attenuators, $JXoDGRUD3RUWXJDOSURGXFLQJDVPXFKDV Oscillation water columns, overtopping and 2.25 megawatts from three huge jointed tubes Inverted- Pendulum device. that float on the surface of the Atlantic Ocean; Abosorbers extract energy from the rise individual power generators are located at the and fall of the waves with a buoy. Once the tubes’ joints and activated by wave motion. energy is extracted it is then converted to „ 1Asst. Professor, electrical energy with a linear or rotary School of Electrical Engineering, generator. KIIT Deemed-to-be University, Bhubaneswar-751024 E-mail: [email protected] Attenuators capture energy by being 2Associate Professor, School of Electrical Engineering, placed perpendicular to the length of the wave, KIIT Deemed-to-be University, Bhubaneswar-751024 this causes the attenuator to contentiously Phone: 7205856704

Science Horizon 49 DECEMBER, 2020 GEOTHERMAL ENERGY: A NEVER-ENDING ENERGY SOURCE BENEATH OUR FEET 1Soumyashree Nanda 2Shreerup Goswami Introduction Geothermal Energy: a mirror to earth’s Nature, the source of all we have, internal temperature infinitely presents us, everything we need. Enormous amount of thermal energy is Even, the tiniest subatomic particle of nature generated and stored in the Earth’s core, mantle is continuously serving us. It is quite and crust. Temperature, at the base of the interesting to know that the temperature, continental crust, ranges from 200 to 1,000°C pressure and composition of materials and at the earth’s core (approximately at underneath the surface of the earth are offering 6371km depth from earth’s surface) us energy, our vital need. The Greek word Geo temperature probably reaches 60000C. Heat is means earth and thermal means heat. transferred from the hot interior to Geothermal energy is generated from heat comparatively cooler nearby rocks mostly by stored in the Earth. Our mother Earth, since conduction. An increase in temperature and its origin, is a vast reservoir of heat. We, the pressure causes some mantle rocks to melt living being have been trying to use it freely and generates magma. As, this rock melt is since prehistoric time. lighter than its surrounding, rises slowly Earth reserves a vast amount of heat. upward to the earth’s crust. Thus, the heat Now the question arises, where this immense energy in this process transfers from the amount of heat comes from? Earth was a earth’s interior to the surface by convection. fireball when it was created and cooled slowly This conductive heat flow makes a rise of as time passed. Thus, the heat released from temperature with increasing depth in the crust the formation of Earth, primordial heat is a on an average of 25-30°C/km (Fridleifsson et major source of thermal energy inside the al., 2008). Sometimes this molten rock Earth. Furthermore, when the transfer of earth’s material remains below the earth’s crust, material takes place to deep inside the earth heating nearby rock and water. When this hot from shallow regions, the gravitational water travels upward through faults and cracks potential energy is released and this generates and reaches the earth’s surface, it is called thermal energy. Again, continuous decay of ‘hot springs’ or ‘geysers’. A constant upward naturally occurring radioactive elements (like migration of gases occurs from the earth’s uranium, thorium, etc.) release radiogenic heat crust to the atmosphere in hot springs. The to the earth. These sources continuously add process is termed ‘earth degassing’. It is heat energy to the earth’s interior (Turcotte uniform across space and time (Mahala et al., and Schubert, 2014; Singh et al., 2016). 1997). However, mostly the hot water stays

50 Science Horizon DECEMBER, 2020 deep, underneath the earth’s surface, in cracks Geothermal Power Plant and porous rock. This is named as ‘geothermal In a porous and permeable rock structure reservoir’. From energy extraction point of below the earth’s surface, when a huge volume view, these deep sources are important. of hot water and steam is trapped and a Depending upon the tectonic settings convection current is set up, a geothermal and geographical locations, this heat transfer reservoir is formed. The main elements in a varies on the surface of the Earth (Condie, geothermal system are a heat source, a 1997). Near the junctions of tectonic plates, reservoir and a fluid, the heat carrier (Dickson the earth’s heat travels easily through magma and Fanelli, 1994). The source of Geothermal from the interior to the surface as volcanoes. energy around subsurface rocks is warmer The geothermal sites roughly correspond to than the nearby region. It is generally a the major zone of earthquakes and volcanic magmatic body of temp 6000C to 10000C activities. The plate boundary of the pacific within a few km from the earth’s surface. A plate, the ring of fire is a major zone of reservoir is a large body of permeable rock, at geothermal energy. The natural collection of a depth that can be accessed through drilling. hot water, thermal springs mainly corresponds This permeable rock body, the heat carrier to tectonic belts, grabens and fault zones. from the depth to the surface of the earth, Geothermal Energy in the Past contains a large amount of fluids, water, or steam. Comparatively cooler rocks, Geothermal energy together includes surrounding the reservoir, are connected to sub-surface steam, hot water and heated rocks. the reservoirs by fissures and fractures giving Hot springs have been used for bathing since a channel for penetration of water to the ground. Palaeolithic times. Furthermore, for eye and skin disease treatment and room heating, it has been used since ancient Roman times. The oldest evidence of a spa, which was marked to be a stone pool, was found in China’s Lisan Mountain built in Quin Dynasty in 3rd Century BCE. Probably, Romans were the first to use geothermal energy commercially by applying admission charges in public baths. of of production presentation Schematic Fig.1. 2012) Kumar, and Mohan (Ganguly Energy Geothermal

Science Horizon 51 DECEMBER, 2020

Means, these cooler rocks, when outcrop on reservoirs’). From the wells, steam is directly the surface, serve as ‘recharge area’ for the piped to the turbine. Thus, the turbine spins geothermal reservoir. Water moves into the and electricity is generated. Steam from these reservoir and is heated up. By convection, this fields has the highest enthalpy (energy hot water transfers heat from the lowest parts content). These well-developed systems are of the reservoir to its upper part. This hot water now found only in Indonesia, Italy, Japan and from geothermal reservoirs provides the force USA. About half of the geothermal electrical that whirls the turbine generators and thus, energy of the world is generated from this electricity is produced. Later on, the already type of field. used geothermal water is made to return down ‘Water-dominated reservoirs’ are the to the reservoir through an injection well for fields where hot water dominates steam. Hot reheating and maintaining pressure. water from these reservoirs is used in ‘flash Based on the temperature and pressure power plants’. Flash power plants produce of the reservoirs, the geothermal power plants energy from hot water. Water having are divided into temperature 120 - 2000C is pumped and made a. Dry steam power plant to pass through a separator and thus some of b. Flash power plant the water changes into steam. This steam is c. Binary cycle power plant used for the spinning of the turbine and generation of electricity. In ‘dry steam power plants’, electricity is produced from dry or superheated steam When hot water in reservoirs has a 0 (means the reservoirs are ‘vapour-dominated temperature 100 - 150 C, they are not hot

52 Science Horizon DECEMBER, 2020

industrialisation. Considering the continuous decrease in the amount of fossil fuel, the necessity of reducing the use of fossil fuel-based energy and the resulting requirement of alternate sources of energy, it is important to explore, exploit and experience the new source of energy like geothermal energy. Depending upon the geothermal parameters and local geographical conditions, geothermal resources can be utilised for the following purposes. a. Geothermal Power Plant Traditionally, geothermal electric plants were built on the boundaries of tectonic plates where high-temperature enough for steam generation. Energy is geothermal resources are available near the generated here from hot water by ‘binary cycle surface. Since 1913, electricity has been power plant’. This hot water is made to pass generated commercially by geothermal steam. through a heat exchanger, where heat is The improvements in drilling and extraction released to some organic fluids say ‘binary technology enhanced the use of geothermal fluids’ or ‘secondary fluids’ (isobutane, resources over a wide geographical area. ammonia, etc.). The boiling temperatures of The hot water (temperature nearly 100 - these binary fluids are less than that of water. 1800C and at a pressure of 2-3 bars) is used Thus, upon heating, these fluids change to for the generation of electricity by the binary vapour and this vapour spins the turbine and cycle method. Thus, geothermal resources electricity is generated. The vapour is then in hilly regions and remote areas can be condensed to fluids and recycled repeatedly. The used for power generation for local people. efficiency of this closed-loop cycle is very low. By binary cycle method, the geothermal However, this binary power plant technology is resources at Puga - Chhumathang observed to be the most profitable and reliable Geothermal field, Ladakh; Tapoban and way to convert a vast amount of low-temperature Manikaran in the Himalayan belt, Bakreshwar geothermal resources into electricity. in West Bengal, Tatapani Geothermal field, Use of Geothermal Energy Chhattisgarh are useful for power generation The demand for power is increasing in India (Sarolkar, 2018). rapidly with population growth and

Science Horizon 53 DECEMBER, 2020 b. Space Heating: drying of various grains, vegetables, fruit crops, Besides hot spring bathing, the most see weeds, onions, wheat, cereals, etc. common and direct use of geothermal energy (Sarolkar, 2018; Lund and Toth, 2020). It is from the earliest time is maintaining warmth in useful for the food industry in Ladakh, Tapoban, individual houses and of entire districts during Parbati Valley, Surajkund, West coast and extreme cold weather. The hot water of Manikaran. Heat radiation and heat exchangers temperature above 600 C can be used in are used for this purpose (Sarolkar, 2018). Manikaran, Parbati Valley, Tapoban areas in the g. Aquaculture Himalayan belt for this purpose (Sarolkar, 2018). This industry requires well-trained c. GreenHouse persons like that of the greenhouse. Low- Hot water of temperature 60 - 800C can temperature water (temperature less than 600C) be used for growing vegetables and flowers in can be used for aquaculture purposes in all seasons under controlled temperature and controlled conditions (Sarolkar, 2018). humidity in cold-weather regions. In India, the Common species cultivated are Tilapia, salmon geothermal resources at Surajkund, Anhoni- and bass, but tropical fish, lobsters, shrimp, Samoni, Tatapani, West coast area, Puga - prawns, as well as alligators, are also farmed. Chhumthang field, Parbati Valley, Tapoban, The energy requirements would be about half, Manikaran can be used for greenhouse if the fish are raised in covered ponds, say by cultivation. a greenhouse. But it is known to be very less in use (Lund and Toth, 2020). d. Refrigeration h. Snow Melting and Soil Warming For refrigeration and thus, preservation of fruits and vegetables, geothermal resources The hot water of temperature greater than of temperature 70 - 1000C can be utilised by 600C, through subsurface pipe circulation, can evaporation in the ammonia absorption-type be used for snow melting and soil warming in refrigeration plant. extreme cold weather conditions. Pass ways for hot water can be constructed under roads e. Tourism and sidewalks to save them from icing over in The thermal springs generally having low- cold weathered regions. Currently, it is temperature water (temperature greater than operated in Iceland, Japan, Argentina, United 400C) are the places of attraction for the States, and Slovenia, and to a limited extent in pilgrims and the tourists. These types of places Poland and Norway (Lund and Toth, 2020). are used for spa, swimming pool in almost all geothermal localities. i. Industrial Uses f. Food processing, Agricultural Crop These are continual operations and have Drying: high energy consumption. Geothermal energy Hot water with a temperature less than is useful for cement block curing, bottling of about 1000C can be used for drying of fishes, water and carbonated drinks, milk 54 Science Horizon DECEMBER, 2020 pasteurization, leather industry, chemical subcontinent are found in the Union territory extraction, CO2 extraction, pulp and paper of Ladakh and two states Himachal Pradesh processing, iodine and salt extraction, borate and Uttaranchal (Ghosh, 1954; and boric acid production, metal part washing, Krishnaswamy and Shankar, 1980; Sankar, timber washing, and wool drying (Lund and 1979; Sankar, 1988; Maheshwari and Toth, 2020). China, New Zealand, Iceland, Parmar, 2002; Sinha and Srivastava, 2000). Russia and Hungary are the leaders in this From 340 hot springs, it is found that 113 application of geothermal energy. are suitable for the exploitation of j. Coal washing geothermal energy and the total resource Hot water of temperature less than 300C potential of all these 113 hot springs was can be utilized for cleaning of coal and separation estimated to be 10, 600 MW (Krishnaswamy of shale from mine. and Shankar, 1982). k. Metal Extraction Razdan et al., 2008 divided the geothermal energy resources of India into In geothermal areas, the presence of different geothermal provinces. They are dissolved heavy metals, rare gases and native grouped to be orogenic and non-orogenic as elements like sulphur are observed and are follows: extracted. At Bakreshwar hot springs, the presence of helium is detected (Mukhopadhyay, Orogenic Regions: The different provinces 1996). Similarly, the deposition of silver is in orogenic regions are: recorded from boreholes at Tatapani, dist. 1. Himalayan Geothermal province Surguja (Pitale et al., 1995). Valuable minerals/ a. Northwest sub-provinces metals extraction from the geothermal b. Northeast sub-provinces reservoirs helps in reducing the cost of geothermal power and technically makes it 2. Andman-Nicobar Island geothermal more attractive (Clutter, 2000). Some more province elements were detected from other Non-orogenic Regions: The different non- geothermal reservoirs. For example, Puga orogenic provinces are: (Cs), Tatapani, dist. Surguja (Ag, He), West 1. Cambay graben geothermal province Coast (Hg?), Bakreshwar (He), Anhoni- 2. Son- Narmada- Tapi geothermal province Samoni (CH4). Helium content of 1% to 2.2% is reported from the steam discharge of 3. West Coast geothermal province borehole from the Tatapani Geothermal field, 4. Damodar valley geothermal province dist. Surguja (Minissale et al., 2000). 5. Mahanadi valley geothermal province Geothermal Energy Resources in India 6. Godavari valley geothermal province There are 340 hot water springs all over 7. North Indian Peninsular geothermal India. Mainly, hot springs in the Indian province Science Horizon 55 DECEMBER, 2020

8. East Indian geothermal province energy source along with other available 9. South Indian geothermal province sources. In India, the geothermal resources are „ It does not pollute the environment. investigated mostly to shallow levels i.e. less „ It is renewable. than 500 m depth. Deep drilling is necessary „ A small part of the land area is required. to know deep reservoirs and thus, planning and „ Does not hamper the ecology of the development of geothermal resources in India region. is need of the hour (Sarolkar, 2018). „ No need of burning of fuel for turbines. Geothermal Energy Resources of Odisha Hence, it encourages the limits for the Seven thermal springs have been located use of fossil fuels. and studied in Odisha. Those are Attri, „ Does not require damming of rivers, Tarabalo, Deuljhori, Magarmuhan, Bankhol, deforestation, mine shafts, tunnels, or Taptapani and Boden (Acharya, 1996; Ball, oil spills like that of exploitation of 1880; Mahala et al., 1997). other energy resources. Tarabalo, the largest hot spring of Orissa „ Less dependence on gulf countries for (2nd largest in India) has more than 50 spots fossil fuels, more jobs and more global (Goswami and Pati, 2008). Still, the trading. Government of Odisha has not taken any Limitations initiative for its identification as a tourist i This leads to a change in landscape, land place. In Tarabalo, geothermal energy is use. immensely available and inexhaustible. Hence, the required steps should be taken for the i Surface and subsurface waters are development of this place and establishment emitted into the atmosphere. Thus, this for a tourist place. water disposal creates a problem. Advantages of Use of Geothermal Energy i Generation of solid wastes. i Release of toxic gases (H S, SO , CO , „ Thermal springs are a natural, 2 2 2 inexhaustible, perennial source of energy radon, etc.) and toxic elements (mercury with a less negative impact on the and arsenic) into the atmosphere. environment. i Types of machinery and exploitation activity create noise pollution. „ It is independent of weather conditions contrary to solar, wind, or hydropower i Bringing out the internal heat and hot energy. water may lead to an imbalance of the earth’s surface and thus, land subsidence „ It is available day and night every day of the year and thus can serve as an additional may occur.

56 Science Horizon DECEMBER, 2020 i Again, imbalance in the earth’s surface increase in geothermal installed capacity (MWt) and interior may trigger more and more was in Iceland, Hungary, France, Egypt and seismic activity. Australia and the largest percentage increase in i Cannot be transported to a large distance. annual energy use (TJ/yr) was in Spain, Yemen, Australia, Kenya and Georgia. Steps to be taken for sustainable and eco- friendly exploitation of Geothermal Conclusion Energy In the outer 100km of the earth, the heat „ Water treatment plant should be designed stored above the surface temperature is about for released water from geothermal 2× 1028cal nearly equivalent to 3×1018 short energy sources. tons of coal or 2×1022 kilowatt-hours „ Care should be taken for utilizing the (White, 1966). Steps must be taken to exploited energy in nearby areas as it increase the traditional direct use of cannot be transported to a long distance. geothermal resources. Furthermore, research should be done for technological „ Noise pollution should be managed advancement in the heat pump sector, as during the power plant design stage. geothermal heat pumps can be used for heating „ Care should be taken for proper disposal and/or cooling in most parts of the world. By of toxic elements and solid wastes inducing fractures and developing an artificial released. geothermal reservoir, granites with high heat Current World Scenario capacity can be exploited and heat from the The increasing alertness and popularity source can be transferred to the circulating of geothermal (ground-source) heat pumps fluid which could then be used for power have the most significant impact on the direct generation (Singh et al., 2016). Renewable use of geothermal energy. The most developed energy sources like geothermal energy can geothermal field in the United States is “The contribute significantly more to the Geysers” in Northern California. According mitigation of climate change by cooperation to Lund and Toth (2020), China, USA, Sweden, without competing with other energy Germany and Turkey are the top five countries sources. Geothermal energy, in near future, with the largest direct-use (with geothermal may prove to be a better substitute for fossil heat pumps) installed capacity (MWt) fuels. accounting for 71.1% of the world capacity References and five countries with largest annual energy 1) Acharya S. 1996. Thermal springs of Orissa. use with geothermal heat pumps (TJ/yr) are: The Explorer. 29-35. China, USA, Sweden, Turkey and Japan, 2) Ball, V. (1880). Jungle Life in India: Or, the accounting for 73.4% of the world use. Looking Journeys and Journals of an Indian Geologist. back to the past five years, the largest percentage Thos. De La Rue.

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3) Clutter TJ. 2000. Mining geothermal benefits evolution of “intracratonic” thermal fluids from from geothermal brine. GHC bulletin. 1-3. Central –Western peninsular India. Earth and Planetary Science letters. 181, 377-314. 4) Condie KC. 1997. Plate Tectonics and Crustal Evolution. Butterworth-Heinemann Ltd.4. 16) Mukhopadhyay DK. 1996. Thermal energy potential of Bakreshwar- Tantloi, Birbhum 5) Dickson MH, Fanelli M. 1994. Small geothermal distrct, W. Bengal. GSI Sp Pub. 45, 56-60. resources: A review. Energy sources. 16(3), 349-376. 17) Pitale UL, Padhi RN, Sarolkar PB. 1995. Pilot Geothermal plant and scope for utilisation of 6) Fridleifsson IB, Bertani R, Huenges E, Lund Tatapani Geothermal field, district Surguja, India. JW, Ragnarsson A, Rybach L. 2008. The Proceedings World Geothermal Congress. 1257- possible role and contribution of geothermal 1262. energy to the mitigation of climate change. ,Q,3&&VFRSLQJPHHWLQJRQUHQHZDEOHHQHUJ\ 18) Razdan PN, Agarwal RK, Singh R. 2008. sources, proceedings, Luebeck. Germany, 20 Geothermal Energy Resources and Their (25), 59-80. Potential in India. Earth Science India. 1. 7) Ganguly S, Mohan Kumar MS. 2012. 19) Sarolkar PB. 2018. Geothermal energy in India: Geothermal reservoirs-a brief review. Journal poised for development. In: Proceedings of 43rd of Geological Society of India, 79 (6), 589-602. Workshop on Geothermal Reservoir Engineering. 8) Ghosh PK. 1954. Mineral Springs of India. Rec. Geol. Sur. Ind. 80, 541-558. 20) Shankar R. 1979. Relavance of geothermal energy and major constraints in its full 9) Goswami S, Pati P. 2008. Physico-chemical development and utilization. Indian Minerals. 33 characteristics of thermal water and soil of (2), 1-9. Tarabalo and Attri geothermal province, Orissa, India. Journal of ecophysiology and occupational 21) Shankar R. 1988. Heat flow map of India and health. 8, 83- 88. discussions on its geological and economic significance. Indian Minerals. 42 (2), 89-110. 10) Krishnaswamy VS, Sankar R. 1982. Scope of development, exploration and preliminary 22) Singh HK, Chandrasekharan D, Trupti G, Mohite assessment of geothermal resources potential P, Singh B, Varun C, Sinha SK. 2016. Potential of India. Records GSI. VIII, 17-40. geothermal energy resources of India: a review. Current Sustainable/Renewable Energy 11) Krishnaswamy VS, Shankar R. 1980. Scope of Reports. 3(3-4), 80-91. development, exploration and preliminary assessment of geothermal resource potential of 23) Sinha AK, Srivastava P. 2000. Earth Resources India. Records of Geological Survey of India. and Environmental issues. ABD Publisher. 60- 111 (2), 17-40. 79. 12) Lund JW, Toth AN. 2020. Direct Utilization of 24) Turcotte DL, Schubert G. 2014. Geodynamics. Geothermal Energy 2020 Worldwide Review. Cambridge University Press. Cambridge, 3. Proceedings World Geothermal Congress 2020. 25) White DE. 1966. Geothermal energy. Bulletin 13) Mahala S, Singh P, Das M, Ray P, and Acharya Volcanologique. 29 (1), 481-483. S. 1997. Traits on Geothermal Gases from „ Thermal Springs of Orissa. U.U. spl. Publ. in 1Office of Joint Director of Geology, Zonal Survey, Geology. 2, 221-225. Sambalpur-768001, Odisha 2Department of Earth Sciences, Sambalpur University, 14) Maheshwari A, Parmar G. 2002. A textbook of Jyoti Vihar-768019, Odisha Energy, Ecology, environment and Society. Anmol [email protected] Publications Pvt. Ltd. New Delhi, 1-48. 15) Minissale A, Vaselli O, Chandrasekharam, D, Magro G, Tassi F, Casiglia, A. 2000. Origin and

58 Science Horizon DECEMBER, 2020 GEOTHERMAL SPRINGS OF ODISHA - A RENEWABLE ENERGY RESOURCE

Sahid Ummar Energy is one of the prime inputs for resources and are naturally replenished both economic development as well as overall because the water is replenished by rainfall well-being of the people. Consumption of and the heat is continuously produced inside energy, both domestic and commercial, has the earth. It is therefore a renewable energy increased steadily over the years. Generation source. It is a reliable source of energy with and supply of power at affordable price has massive potential. always remained a challenge before the The resources of the geothermal energy Government. Our indigenous conventional consist of heat energy from the Earth’s interior energy sources such as coal, oil, gas and stored in both rock and trapped hot water. It is nuclear energy may not carry us for very long a massive renewable resource as the tapped time. Thus a major effort is required to heat from an active reservoir is continuously consider all alternatives to overcome the restored by natural heat production. The problem and gradual introduction of renewable outward transfer of heat occurs by means of energy resources in energy consumption, on conductive heat flow and convective flows of long-term basis, is the only alternative. molten mantle beneath the Earth’s crust. The Geothermal energy is an important heat is transferred from the interior of the renewable resource. It is one of the rare earth to the circulating water that gradually forms of energy which is not directly or seeps down through the ground and meets the indirectly from solar energy. The rocks heated by magma by the conduction and WHUP´Geothermal”RULJLQDWHVIURPWZR*UHHN convection processes. The underground ZRUGVµgeo’, meaning earth, and ‘thermos’, circulating surface water in aquifers acquires meaning heat. Geothermal energy is the energy heat from the earth’s thermal gradient of around obtained from the earth (geo) from the hot 30°C/km. At places, geothermal gradient is rocks present inside the earth. They are natural more than the normal due to some geological phenomena linked to earth’s internal energy; conditions. The heated water then rises back geothermal energy. toward the surface of the earth Geothermal springs are the springs that E\FRQYHFWLRQWKURXJKJHRORJLFDOIDXOWVDQG discharge water at temperatures noticeably fractured rocks and emerges as hot springs or higher than the atmospheric temperature of even geysers. Sometimes the hot water the surrounding and ascend from great depth. becomes trapped below the surface as a Geothermal reservoirs come from natural geothermal reservoir. The geothermal fields

Science Horizon 59 DECEMBER, 2020 are invariably tectonically controlled, and often these springs shows moderately acidic to found in areas of block faulting, grabens or moderately alkaline character (pH: 5.05–8.93). rifting with reservoir depth within 1-3 km. Total dissolved solids (TDS) also shows a There are geothermal springs in many locations wide variation with maximum 595 mg/L at all over the crust of the earth. The heating Deulajhari. The thermal spring water from process is due to geothermal gradient, decay Attri, Tarabalo and Deulajhari belongs to Na– of radioactive materials and exothermic Cl water type which is due to the circulation reactions. through granitic rocks. Fortunately, Odisha is also endowed with Geothermal energy resources have been a number of hot springs. These hot springs commercially utilized in many countries. have been traced at Attri, Taptapani, Tarabalo, Utilisation of the resources depends primarily Deuljhori and Bamini areas in Odisha. The on the quality of available resource and its temperature of the thermal springs ranges size, the regional economic conditions, i.e. from 360C to 670 C. The volume of water the economic need and potentials of the area released from these remains more or less in which the geothermal resources are constant, but with a difference in the rate of located. But it has an inherent limitation of discharge. being site-specific and not uniformly These thermal springs belong to distributed in space and time. Mahanadi Geothermal Province, which is an Being abundant, environmentally benign Archean/Pre-Cambrian Geothermal Province. and renewable, it is a preferred choice for an They do not have any volcanic association. alternative energy resource. The use of They are more or less aligned in specific geothermal energy obviously replaces fossil tectonic lineament of the region and may be fuel and prevents the emission of greenhouse related to structural disturbance. They are gases. The natural replenishment of heat mostly confined along the periphery of the from earth processes and modern reservoir Gondwana Graben. The rock types encountered management techniques enable the sustainable at Attri, Tarabalo, Deulajhari and Taptapani are use of geothermal energy as a low-emission, laterite, khondalite, charnockite and granites. renewable resource. Due to its low emissions The Attri and Tarabalo hotsprings are geothermal energy is also considered to have manifested by NW-SE and NE-SW fractures/ excellent potential for mitigation of global lineaments. These fields are often warming. characterized by seismicity and earthquakes „ of lesser magnitude are observed frequently. Former Sr. Geoscientist, GSI, VIP-130, Ekamra Vihar The chemical constituents of the water Bhubaneswar-751 015 are usually related to interaction between water and rock.The thermal water discharging from

60 Science Horizon DECEMBER, 2020

HYDROGEN ENERGY

Er. Ramesh Chandra Sahoo Hydrogen is considered as the simplest electricity through an electrolyte or water element in existence. It is also one of the Hydrogen (H2) and Oxygen (O2) are separated. most abundant elements in the earth’s crust. Adding a little salt as catalyst improves the However, hydrogen as a gas is not found in process efficiency. The charge breaks the nature. Being lighter than air it rises into the chemical bond between Hydrogen and Oxygen atmosphere. As a result, it is always associated and gathers them separately at cathode and with other elements in compound form such anode respectively. as water, coal and petroleum. It has to be 2. Natural Gas segregated for use. Hydrogen is an easy carrier Use of thermal energy separates of energy but presently only in research stage. Hydrogen from the carbon components in The entire world is now in search of methane and methanol. The reaction alternate sources of energy. The principal decomposes the fuel into Hydrogen and carbon reason is demerits of use of fossil fuels as a monoxide. But carbon monoxide is unstable. source of energy. In addition to its dwindling A shift reaction works to change carbon deposit sources, it also generates green house monoxide and water to carbon dioxide and gases resulting in severe pollution and global hydrogen. warming. Hydrogen is an alternate efficient 3. Coal energy carrier. The steps for its generation, transportation and use are to be developed Hydrogen can be produced from coal with zero emission. Then only purpose of an through a variety of gasification processes. In efficient alternate fuel is met. practice high-temperature entrained flow processes are favoured to maximise carbon Three steps are involved from generation conversion to gas. to use of Hydrogen as an energy carrier. Those are generation, storage, transportation and Storage delivery. The focal point of Hydrogen energy Different methods are used for storage. is, it can be stored for considerable period, as Forms of storage along with its advantages and compared to electricity. disadvantages are given in the Table -1. Generation- Fuel Cell & It’s Application 1. Electrolysis Fuel cells are one of the key enabling It can be produced from water by technologies in processing of Hydrogen. It Electrolysis. It is well known that by passing has been developed specifically for Hydrogen Science Horizon 61 DECEMBER, 2020 Table-1 Storage form Advantages Disadvantages Compressed Gas Reliable Indefinite storage time. Higher capital & operating cost. Easy to use. Heat may cause container rupture Liquid High density at low pressure High cost. Low temperature needed. Escape may cause fire or asphyxiation. Metal Hydride High volume efficiencies. Capital intensive. Easy recovery. Very safe Heavy storage tanks are needed. gas. Fuel cells have several benefits over fuel cells, Phosphoric Acid (PA) fuel cells, conventional engineering practice. It produces Molten Carbonate (MC) fuel cells, Direct negligible quantity of green house gas. If pure Methanol (DM) fuel cells. hydrogen is used as a fuel, fuel cell emit only heat and water as by-product. A fuel cell is a device that converts the chemical energy from the fuel into electrical energy. A chemical reaction takes place with the help of oxygen or some other oxidizing agent. It differs from battery as it requires continuous input of fuel and oxygen to produce electricity. Production continues as long as inputs are maintained. Chemical reaction starts when hydrogen atoms come in contact with anode in the cell. Electrons from the atom are separated. The atoms are now ionised to carry a positive electric charge. The negatively charged electrons carry the current through the external wires Hydrogen Fuel Cell to do the work. The electrolyte in the fuel cell Hydrogen Transportation and Delivery carries electrically charged particles from one It is done by using high-pressure electrode to the other. The role of the catalytic cylinders, tube trailers or pipe lines. High agent is to speed up the reaction at the electrodes. pressure cylinders are very expensive and Type of fuel cells difficult to transport. Different types of fuel cells are Alkaline Liquid Hydrogen Transport fuel cells (AFCs), Polymer electrolyte Liquid hydrogen is transported using membrane (PEM) fuel cell Solid Oxide (SO) special double walled insulated tanks to prevent

62 Science Horizon DECEMBER, 2020

development of standards and codes. These codes are to be applicable for use of Hydrogen energy and fuel cells. Those names are given in Table-2. Public Awareness Unless the public accept it as an alternate green energy the development will not bear fruit. Awareness therefore has to be created through various media Liqid Hydrgen Ship intervention and seminars and boil-off of the liquid hydrogen. Some times workshops. All officials of Government, liquid nitrogen external cooling is also used corporate sector, equipment manufacturers, to avoid heat transfer. staff involved for its installation and maintenance should be target audiences. Metal Hydraid Transport Needless to say that the general public are the It is done by absorbing hydrogen with a destination audience. So education at metal hydride. Then get the system with hydride Table-2 International Organisations Indian organisations. Fuel Cell and Hydrogen Energy Association Bureau of Indian Standards (BIS) (FCHEA). National Renewable Energy Laboratory (NREL) Petroleum and Explosives Safety Organisation (PESO) National Fire Protection Association (NFPA) Oil Industry Safety Directorate. International Codes Council (ICC) International Partnership for the Hydrogen Economy (IPHE) tanker suitably transported to consumer elementary, secondary and university levels is premises. Get it segregated there for use. The essential. Suitable mechanism is needed for empty hydride tanker can be returned to source every level separately. Curriculum and training for reuse. The cheapest method of programmes for teachers is essential to develop transportation depends on the quantity proficiency for key target audiences. delivered and the distance. „ Safety Codes & Standards 403, Sahid Nagar, Bhubaneswar Mob.: 9438011072 Several Indian and International organisations have been working on the

Science Horizon 63 DECEMBER, 2020 BIODIESEL-FUEL FOR THOUGHT

Dr. Manas Ranjan Senapati Fossil Fuels have been the prime source into biodiesel. The chemical process is called of energy of power for domestic, Transesterification. The process was developed transportation and industrial sector for more as early as 1853 by scientists E. Duffy and than a century. The rapidly increasing J.Patrick. Transesterification is the process of consumption and consequent depletion of using methyl alcohol in the presence of a these reserves clearly show that the end of the catalyst such as sodium hydroxide or potassium fossil fuel era is not very far. For developing hydroxide to chemically break the molecule countries like India, rising world prices of of the raw renewable oil into methyl ester crude oil and petroleum is a serious cause for (BIODIESEL) of the renewable oil with concern. We import almost 70% of our glycerol as a by- product. Biodiesel, when requirement of crude oil and in future it is used as a pure fuel, is known as B100. However, likely to increase to 85%. This is high time to it is often blended with petroleum-based diesel ponder over and to find an alternative to the fuel and when this is done, the blend is fossil fuel. The green fuel Biodiesel is one designated “BXX” where XX is the percentage such alternative to partly replace the petroleum of biodiesel in the blend. For example, B20 is crude and be the fuel of the future. Rudolf a blend of 20% biodiesel and 80% petroleum Diesel’s prime model, a single 10 ft (3m) iron diesel fuel. Biodiesel can be used in the pure cylinder with a fly wheel at its base, ran on its form, or blended in any amount with diesel fuel own power for the first time in Augsburg, for use in compression ignition engines. The Germany, on August 10, 1893. In remembrance total fossil energy efficiency ratio (i.e., total of this event, August 10 has been declared fuel energy/total fossil energy used in “International Biodiesel Day”. Rudolf production, manufacture, transportation and Diesel demonstrated a diesel engine run on distribution) for diesel fuel and biodiesl shows peanut oil (vegetable oil) at the world fair in that biodiesel is four times as efficient as Paris, France in 1900. diesel fuel in utilizing fossil energy (3.215 for Bio diesel is a non-toxic; biodegradable biodiesel vs. 0.8337 for diesel). diesel fuel made from vegetable oils, animal Advantages of Biodiesel fats and used or recycled oils and fats. i Higher flash point of biodiesel makes it Biodiesel could be an excellent renewable safer to store and transport. fuel for diesel engines. It is derived from i The Higher cetane number, thus the vegetable oils that are chemically converted greater the probability of ignition and

64 Science Horizon DECEMBER, 2020

combustion process being initiated thus oils like Karanja, Mahula, Neem, Kusum etc higher engine performance. can also be converted into biodiesel. In India i Regular petrodiesel fuel particulates are it is usual practice to produce biodiesel from carcinogenic. Using biodiesel fuel or non-edible oils. Rapeseed and soyabean oils blending it with regular diesel fuel can are mostly used to produce biodiesel in USA. reduce the production of these Mercedes Benz C 220 CDI vehicle was run in carcinogenic emissions. It reduces CO, various states of the country using 100% sulphates, unburnt hydrocarbons, biodiesel by CSMCRI, Bhavnagar without any polycyclic aromatic hydrocarbons (PAH problem with a mileage of 13.5 km per litre s), particulates & NOx emissions as which is comparable with fossil fuel. compared to diesel emissions. i Biodiesel can even make engines smell better. An engine powered by biodiesel actually smells like French fries! i Biodiesel fuel is a good lubricant, which helps engines to last longer. i Biodiesel is a renewable and environment friendly fuel. i Biodiesel use helps to reduce greenhouse Fig.1 : Shatabdi Express Trial gases. The overall ozone forming potential of bio diesel is 50% less than the diesel fuel. i Biodiesel has the highest energy balance of any transportation fuel. i Biodiesel degrades in the environment as fast as sugar and is 10 times less toxic than table salt. Fig. 2 : Money Plant Jatropha Biodiesel buses are in use in Europe and in the mid western United States. In India In July 2002, the Planning Commission successful test run drives have been done by constituted a Committee for the development using biodiesel produced from Jatropha Curcas of biofuels, which recommended the creation (Ratanjyot in Hindi & Baigaba in Odia). of Biodiesel Mission to coordinate the initiative Shatabdi train was run from Delhi to Amritsar and enterprise of individuals, communities, oil using B5 (5% biodiesel) blend and no problem companies, industries, businessmen as well as was observed during the run. Other non-edible Government. In Oct. 2005, the Union Ministry

Science Horizon 65 DECEMBER, 2020 of Petroleum and Natural Gas (MPNG) FUEL FROM announced the biodiesel policy from January CARBON DIOXIDE 2006. The Public Sector oil marketing companies viz. Indian Oil, Hindustan Petroleum & Bharat Petroleum will purchase biodiesel Dr. Ramesh Chandra Parida from private operators at Rs. 26.50/litre. The The Paris Agreement on Climate Change purchase price has reportedly come from (2015) had set the guidelines to arrest the estimates of the planning commission and twenty Global Warming below 2° above the purchase centers will be set up in fifteen states temperature of the pre-industrial era (But, the by the oil companies. A cell has been created as Intergovernmental Panel on Climate Change the Biodiesel Board to coordinate Jatropha or IPCC has warned that even it can be too high cultivation and biodiesel production with target to save the Earth from its devastating impacts up to 500,000 tons of biodiesel per year. and therefore, has proposed to revise it as There is an urgent demand for the 1.5°). In order to achieve that it was proposed plantation of Jatropha Curcas which can not to limit carbon-dioxide, the number one green only mitigate the unemployment problem but house gas, at 400 parts per million (ppm) in the also solve fuel crisis in future. atmosphere. However, most of the 197 „ participating nations, especially, the industrially Dean, Science BPUT and Professor of Chemistry, developed one, have been obeying it in breach Trident Academy of Technology, Bhubaneswar-751024 rather than in observance. As a result, the level E-mail: [email protected] of carbon-dioxide has surpassed the critical Nuclear Power Plants in India level to reach 407 ppm in 2017 and by now it Location Units Total might have increased further. In view of that Capacity (MW) many scientists believe that the Global Warming Tarapur 2x160 has already reached an irreversible stage and by 2x540 1400 the middle of the present century the temperature of the earth’s atmosphere may Kota 1x100 increase by 1° to 3°C above the set limit, 1x200 leading to large scale melting of glaciers, rising 4x220 1180 of the sea level by 5 to 10 meters, which may Kalpakkam 2x220 440 lead to the submersion of a vast coastal area Kaiga 4x220 880 including a number of islands around the world. Kudankulam 2x1000 2000 The other impacts are likely to be increasing Narora 2x220 440 frequency of devastative cyclones, floods and Kakrapar 2x220 440 draughts as well as deforestation and other Total 6780 MW ecological disasters. That is why, they have

66 Science Horizon DECEMBER, 2020 been trying various methods to capture carbon- polluting fuel, from the major green house gas dioxide from the atmosphere and to convert it can go a long way in addressing the problem. into some harmless useful products and They call their success to be miraculous probably, the best among those is to use it to because, the result was beyond the expectation. make fuel. By now certain laboratories have However, it was the magic played by the new already achieved remarkable success in it. kind of catalyst they used. It was prepared by One of the pioneering steps in this absorbing nitrogen on graphin (carbon) nano- direction has been taken by the Oakridge particles and putting it on the surface of nano- National Laboratory of the US Department of particles of copper, which was used as the Energy. In a paper published in the Chemistry electrodes in the electrical system. The process Select (October, 2016), its scientists have is relatively cheaper and takes place in water at reported that they have succeeded in producing ordinary temperature. Therefore, the researchers ethyl alcohol from carbon-dioxide by using are hopeful that the technology can be developed carbon, copper and nitrogen as catalyst. Its for use in commercial production of ethyl senior author Dr. Adam Rondinov admits that alcohol, a clean fuel. the success came to them in an unexpected Another epoch-making effort to convert manner. In their experiment they passed carbon-dioxide into fuel has been reported in carbon-dioxide through water in presence of the research journal “Jule” (June, 2018) by a the above catalyst, anticipating that it might group of scientists led by Dr. David Keith of start some type of complex chemical reaction Harvad. Called as air to fuel or A2F in short, their to make the process of combustion reversible process involves capturing air with carbon- (carbon-dioxide is non-supporter of dioxide and to convert it into hydrocarbon fuel. combustion). However, to their astonishment They have formed a company called “Carbon it directly resulted in the production of ethyl Engineering” to take up the process for alcohol and its concentration in the solution commercial purpose. was as high as 63%. Keith and his team had been working on Every carbon based fuel on burning the problem for the last several years. They were produces carbon-dioxide. As the numbers of capturing carbon dioxide and combining it in a industries, vehicles and population are growing reactor with hydrogen, obtained from the our energy requirement is also increasing electrolysis of water, thereby producing globally at a rate of about 6% per annum and hydrocarbons. They have named the process as carbon based fuels serve as the major source “carbon-neutral-fuel production.” to meet it, which is mainly responsible for the To capture carbon dioxide from ambient Global Warming and Climate Change. air was first attempted in 1950s, as a pre- Therefore, the efforts of Rondinov and his co- treatment of it. Then in 1960s steps were workers in generating ethyl alcohol, a non- taken to produce feed stock hydrocarbon from

Science Horizon 67 DECEMBER, 2020 that gas which could be used in mobile nuclear TOWARDS power plants. However, those processes were CLEAN ENERGY neither quite efficient nor cost effective. Now, the Carbon Engineering scientists have overcome those. Dr. Nikhilanand Panigrahy Their process involves sucking in ambient A modern day society needs high speed air and passing it over a thin plastic surface that in day to day life to progress. Otherwise it will has a solution of potassium hydroxide, which remain like in the primitive state of bullock- absorbs carbon dioxide to form potassium cart age. Since energy is defined as the capacity carbonate. Thereafter, the salt is piped in to a for doing work, it is essential that more and reactor containing calcium hydroxide, in which more energy should be generated and made they react to produce pellets of calcium available to the citizens to work and remain carbonate and regenerate potassium hydroxide. active for prosperity. Physicists have Then the pellets are heated to release carbon enumerated different kinds of energy, viz, dioxide, which is mixed with hydrogen, obtained thermal, chemical, nuclear, electrical from the electrolysis of water, to make mechanical, light, magnetic, etc. Further there hydrocarbon fuel. In the process calcium is another classification like potential and hydroxide is also regenerated. kinetic energy. Physics has also set a golden In a report published in the Nature (7 rule that the total energy can neither be created June, 2018) Dr Jeff Tollefson, another scientist nor destroyed. But it can be transformed from involved in the project has indicated that the A2F one form to the other. So potential energy can is likely to be economically viable as it may cost be transformed to kinetic energy and vice anywhere between $50 to $100 to produce one versa. We must have to transform energy from ton of carbon dioxide and 1 million tons of it can one form to another, as per our requirement. be converted in to nearly 30 million gallons of As we have seen, normally during cycling jet fuel, diesel or gas. Besides, another advantage we use individual’s physical strength. So the of the process is that it is reversible and therefore, speed cannot be very high. We have to take both the raw materials, potassium hydroxide and shelter in other forms, where the amount of calcium hydroxide are regenerated, which can be energy is quite large. used again and again. However, the ultimate benefit Each country frames its own energy – that can be derived from it will be the successful policy, based on energy-requirement. Energy removal of carbon dioxide from the air in order to can be produced from different sources like arrest the Global Warming and Climate Change. coal, crude oil, natural gas, nucleus, water and „ Retired Professor, OUAT, Usha Nivas, 124/2445, renewable sources. Khandagiri Vihar, Bhubaneswar-751030 E-mail: [email protected] We may tabulate the energy sources in Mob.: 9937985767 Table-1.

68 Science Horizon DECEMBER, 2020 Table-1 Non-renewable a) Fossil fuels : Example: oil (or crude oil), coal and natural gas b) Mineral fuels : Example : Uranium, Thorium Renewable a) Solar energy: Example : From sun b) Wind energy c) Tidal energy like falling or flowing of water d) Biomass (wood, forest residues, human waste from sewage plants) e) Geothermal (Heat, derived within the surface of earth, water-stream on earth’s surface) All the sources mentioned above are As can be seen, we are at present utilizing termed as Primary Energy (PE), as they are coal to a large extent to meet our energy found in nature without any human engineering. needs. But this is not a good sign, as it pollutes However, these unconverted or original fuels the environment. A recent study has shown should be subjected to transformation process that the thermal power Station in Singrauli, by the technologists to obtain secondary Neyvell, Korba, Chennai, Ramagundam, energy sources, which then will be ready for Visakhapatnam, Talcher, Kutch, Surat, our consumption. Chandrapur and Kovadi are top emission hot To have an idea of the energy-situation spots. Further adequate provisions are not in India, Figure-1 may be referred.

Energy Resources: Primary Vs Secondary Science Horizon 69 DECEMBER, 2020

made for fuel-gas desulphurisation. It is global SO2 emission in 2019, in spite of 6% estimated that India accounted for 21% of fall in that year, being the steepest decrease of this undesirable emission in the last four years,as per Green peace report and center for research on Energy and clean Air (Ref: New Indian Express, 9 October 2020). Further it is heartening to learn that the share of fossil-fuels is set to decline from 85% of total primary energy demand in 2018 to between 20% and 65% by 2050. (Ref: Times Of India, 16 Sept 2020)

The drop in SO2 emissions along with fossil fuel usage, which is set to drop for the Fig.-1: first time, provides us hope for clean energy. We must keep in mind that our goal is for the use of clean energy. This is the energy, derived from renewable, zero-emission sources, as well as energy saved through Energy Efficiency, EE, as defined by NCSEA (National Council of Structural Engineers Associations). Let us hope that the world will be gifted (NOTE: Mtoe of is unit of energy. It’s value is with an eco-friendly atmosphere in future. one million toe (ie, Megatoe), where one toe is „ the energy equal to the amount of energy released Badakhemundi Bunglow by burning one tonne (1,000 kilograms) of crude Utkal Ashram Road Berhampur - 760001, Odisha oil. It is approximately 42 gigajoules or 11. 630 Mob: 9437026651 megawatt hours. email: [email protected]

70 Science Horizon DECEMBER, 2020 ENERGY SCENARIO IN RURAL AREA – TIPS FOR RENEWABLE SOURCES

Dr. Bijay Ketan Patnaik Globally, it is estimated that 2.67 billion from stoves and these emissions add up to the people (i.e. 34 percentage of world population) climate change burden of the world. The 2010 still rely on biomass for cooking food. The Global Burden of Disease Report established bulk of cooking in villages is still done using that indoor air pollution from cook stoves is a firewood and twigs. India lives in villages. primary cause of diseases and death in South Around 66 to 70 percent of India’s population, Asia. As far as 1.04 million premature deaths close to 700 million still live in rural areas, are caused by exposure to biomass burning in without access to electricity or other source poorly ventilated homes. It is even estimated of commercial energy including LPG. Meeting that for around 33 percent of world population, their energy requirement in a sustainable specifically in developing countries, cooking manner continues to be the major challenge by using biomass will continue upto 2030. for the country. Despite the availability of the In India, census 2011 shows that 75 commercial sources of energy such as percent of rural households continue to use electricity, petroleum oil, diesel, LPG, coal biomass and cow dung to cook as against 21% etc, the non-commercial source of energy of urban Indian households. In addition, the data namely fuel wood, cow dung and agricultural from the National Sample Service Office residue still constitute the bulk source of (NSSO) on energy sources of Indian households domestic energy in rural India. In rural India, for cooking and lighting reveals that nothing the household sector accounts for nearly 75% has changed in past two decades ending 2009- of the energy used. Out of this cooking 10. During 1993-94, as many as 78% accounts for almost 90% of the household households in rural India used biomass as energy use with the rest taken up for lighting cooking fuel and even during 2009-10, 76 and heating. Biomass fuels provide 85-90% percent used this as fuel. During this period, of the domestic energy and 75% of all rural when urban India moved to LPG from 30 energy requirement. This not only leads to percent to 64 percent, rural India remained depletion of forests but also causes indoor air where it was. pollution, affecting health of rural people, LPG Supply in Rural Sector especially women folk, who spends hours and hours before ‘chullah’ for cooking. There is a paradigm shift in use of LPG by rural population during last five years, thanks Poor rural women, using chullah –cook to vigorous pursuit of Government’s ‘Ujjala’ stoves for daily cooking, breathe toxic emissions

Science Horizon 71 DECEMBER, 2020 policy. Leaving aside various claims made by consisting of a photovoltaic module, a light government regarding bulk distribution of free source usually an energy efficient CFL or LPG connection in rural areas, from the various LED lamp, solar panels, battery, charge data that could be gathered, one could find a controller and there may also be an inverter. definite co-relation between wealth, The lamp operates on electricity from batteries, availability, affordability and method of cooking. The same NSSO data shows that only the highest class of monthly percapita expenditure (amongst rural folks) does the households make the transition to LPG in rural India. But in Urban India, in contrast, even households in the lower level of monthly percapita expenditure, LPG connection is taken. However, a thorough discussion is also needed to gauge the impact of newly introduced Ujjala Yojana of Government in the increased LPG use and dependency in rural section. Solar Lantern Pending that, we may analyze the energy charged through the use of solar photovoltaic requirements of rural India, besides cooking by panel. In the evening, the lantern with the charged using biomass, fuel wood and cow dung as battery is disconnected from the module and is primary source of energy. Against this available for indoor and outdoor use. Though background, renewable source of green and clean initially solar lantern is costly and weather energy such as solar and wind energy and biogas dependent, still in remote villages/forest offer alternate options. Besides energy villages, where electricity has not yet made any requirement for cooking, another prominent need inroads, solar powered household lighting in rural areas is both street lighting and lighting replaces other light sources like candles or of individual houses. Inspite of Government kerosene lamps. Though the initial cost of promise and effort to provide electric line to investment is high, but in the long run, the each village of the country, it may take some operating cost is lower than kerosene lamps, time to achieve the goal, specifically due to because renewable energy from the sun is free. remoteness and inaccessibility of certain villages. Further, they produce no indoor air pollutions. Solar street lighting system and solar lantern are Solar Street Lighting System clean and quick alternative. A solar street lighting system has a pole, Solar Lantern a battery enclosure, a battery, an LED or CFL A typical solar lantern is a portable source lamp and photovoltaic module. During the day of lighting in remote village households, hours, the module charges the battery. In the

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Solar Cooker Due to its simplicity and ease of handling, solar Solar Street Light cooker has found easy acceptance in rural areas. evening, when the generation through the solar Solar Water Pumping PV module stops, the controller automatically Many of the Indian villages are switches on the light for lighting the streets or accustomed to raise only one crop in the field roads. In the morning, after sunrise, when the depending on monsoon. In absence of module starts producing power again, the electricity digging of bore-well for irrigation controller automatically switches off the light. purpose is not feasible. In that case solar At present solar street lights are being used in water pumping system is handy which could many remote areas of Rajasthan, islands of be used to draw water for irrigation as well as Sunderbans and in many remote villages, still for drinking. A typical PV water pumping situated inside Tiger Reserve areas of the system comprises a DC or AC, surface mounted Southern states. or submersible or floating pump that runs on Solar Cooker power from a solar PV array. This array is mounted on a suitable structure and placed in This device may serve as a supplement a shadow free open space with its module to already vigorously penetrating LPG system facing south. In this case, solar radiation is for cooking in rural areas. Solar cookers can converted into direct current (DC electricity) be used for cooking different types of food and which is subsequently converted into AC power for steaming, roasting, boiling etc. It consists and used to run the pump. Solar pumping of an airtight box with a double glass cover. A system can be used in community water supply reflection is placed over it for boosting the system, agriculture and forestry. The author solar radiation and thus increasing the has seen the use of solar water pumps in temperature inside. The cooker can also be project tiger areas of southern scanty rainfall used to boil 2 to 3 litres of water in half an hour. states to make provision of water supply for

Science Horizon 73 DECEMBER, 2020

energy demand. The three phase Jawaharlal Nehru National Solar Mission has set up an ambitious road map, 100,000 MW of solar power by 2022. The mission requires drastically ramping up solar energy production in India. But technology, cost and operational challenges are not easy to overcome. Solar Water Pump wild animals. This type of solar pumping system However, in contrast to other is of low maintenance cost and does not cause conventional energy sources, renewable energy environmental pollution. provides greater flexibility and more competitiveness in the long run. With the Mini Hydel Project initiative from India, 121 countries of the In remote hilly terrain, where water flows world, situated between tropics of Cancer and down on hill slopes, with a cascading effect, tropics of Capricorn normally receive sunlight mini check dams can be built up and water around 240 days per year; have formed an flow to down below could be channelized. By International Solar Alliance and are thriving putting a small turbine under the channelized hard to harness solar power to maximum flow, small amount of electricity could be possible extent. The objective of this alliance generated and that could be used for street is that by introducing modern technologies, lighting purpose in nearby inaccessible villages. for renewable solar energy production, the Wind Energy drudgery of the women folk in rural areas Harnessing wind energy, where it is could be mitigated along with provision of feasible, can also be done and successfully solar power driven electricity with minimum used for pumping water, mowing of lawns and or zero environmental damage. for electricity generation. Currently, India has References the world’s 4th and 6th largest installed wind 1. State of India’s Environment, 2019. and solar capacities respectively as per 2. Down to Earth – 16-31 January, 2020. International Renewable Energy Agency. 3. Dream 2047, Vol. 18, May-2016. Historically, the wind sector spearheaded the „ renewable energy narratives in India. However, Retd. Chief Editor, ‘Bigyan Diganta’, 57, Jagamohan Nagar, Jagamara, in the current policy regime it has lost ground Po.: Khandagiri, Bhubaneswar-751030 to solar. In 2010, India made the leap to Mob.: 9437000904 harness solar power to meet its ever increasing

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CONTENTS OF THE 'SCIENCE HORIZON' 2020 Subject Author Page JANUARY-2020 1. Editorial : Climate Emergency Er. Mayadhar Swain 2 2. Perioidic Table: Beyond the Seventh Period Prof. Ramesh Chandra Parida 4 3. Browning Reaction Er. Timira Mishra 10 4. Demonstration and Establishment of Quantum Supremacy Abinash Lenka 13 5. Cubic Sequence Er. Mayadhar Swain 15 6. Proxima & Ten Dimensions Ansuman Dash 16 7. Something to Know About HbA1C Test Dr. Kalyanee Dash 19 8. Pouch for Couch Prof. Prafulla Kumar Mohanty 21 Miss Reshma Kerketta 9. Soil Health Management in Command Area Antaryami Mishra 32 Prava Kiran Dash Subhashis Saren Badireddi Revathi Tupaki Lokya 10. Air Pollution in Delhi Nikunja Bihari Sahu 34 11. How Cells Adapt to Oxygen Availability Dr. Soumendra Ghosh 36 12. Certification Programmes in India Dr. Rajballav Mohanty 38 Dr. Pramoth Kumar Pani Dr. Taranisen Panda 13. The First Woman Nobel Laureate in Physiology or Medicine Prajnaparamita Mishra 42 14. Quiz: Earthquakes Sri Utkal Ranjan Mohanty 44 15. Recent News on Science & Technology 46

FEBRUARY-2020 1. Editorial : Science for the People and People for Science Er. Mayadhar Swain 2 2. Raman’s Journey into Light Dr. Dwijesh Kumar Panda 4 3. Last Solar Eclipse of the Year Nikunja Bihari Sahu 6 4. Artificial Intelligence in Sports Mrs. Sushree Mishra 9 5. Plastic and Environment Dr. Brundaban Chandra Padhi 12 6. Successful Parenting Dr. (Mrs.) Pritishri Parhi 16 7. Refuse Derived Fuel Ansuman Dash 18 8. Trilobite: The Most Primitive Lover Prof. Ramesh Chandra Parida 21 9. Extract More Sponge Iron to Boost Production of Prof. Dr. P.K. Jena 25 Steel & Increase Employment 10. The Botanical Dance of Death: Programmed Cell Dr. Taranisen Panda 29 Death in Plants Dr. Raj Ballav Mohanty

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Subject Author Page 11. Phosphorus Management in Crops Antaryami Mishra 34 Prava Kiran Dash Srikanta Kumar Sethy Subhashis Saren Rojalin Priyadarshini Singh 12. Sustainable Agricultural Management Programmes in India Ishra Roy 36 Dr. Sanjeeb Kumar Das 13. Biofertilizers - A Boon to Sustainable Agriculture Monika Ray 41 Meenakshi Prusty 14. Quiz: Physics Binod Chandra Jena 46 15. Recent News on Science & Technology 47

MARCH-2020 1. Editorial : River Pollution Er. Mayadhar Swain 2 2. The Riddle of Life Dr. Dwijesh Kumar Panda 4 3. Nuclear Catastrophe Ansuman Dash 7 4. Impacts of Climate Change in India Nikunja Bihari Sahu 11 5. Delhi: The Gas Chamber Dr. Sailendra Narayan Swain 13 6. Butterfly: We Do Not Know Dr. Raj Ballav Mohanty 16 Dr. Taranisen Panda 7. Soil Management in Odisha Antaryami Mishra 18 Prava Kiran Dash Srikanta Kumar Sethy Subhashis Saren Rojalin Priyadarshini Singh 8. Eating Instant Noodles Every Day ? Dr. Chitrotpala Devadarshini 22 Ms. Priyanka Parida 9. Rutherford (The Man Who Saw The Inner B. Sahoo 24 Structure of the Atom) P.K. Pujapanda 10. Vikram Sarabhai: Dazzling Star Tulashi Prasad Mohapatra 30 11. World Tuberculosis Day: ‘It’s Time-End TB’ Dr. Choudhury Satyabrata Nanda 33 12. Coronavirus in China Prof. Prafulla Kumar Mohanty 38 13. Some Applications of Nanoscience and Nanotechnology Pankaj Kumar Samal 43 14. Quiz Er. Timira Mishra 45 15. Recent News on Science & Technology 47

APRIL-2020 1. Editorial : Fundamental Forces of Nature Er. Mayadhar Swain 2 2. Climate Change and Impact on Human Health Dr. Sundara Narayan Patro 4

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Subject Author Page 3. Vanishing under the Surging Seas Nikunja Bihari Sahu 12 4. Energy for the Future Dr. Dwijesh Kumar Panda 15 5. Compressed Bio Gas Er. Ramesh Chandra Sahoo 19 6. New Coronavirus Disease: An Emerging Threat Dr. Choudhury Satyabrata Nanda 22 7. Energy Plantations Dr. Sanjeeb Kumar Das 24 8. Mycoplasma: An Old and Bold Organism Prof. Prafulla Kumar Mohanty 32 9. A Tribute to Rajendra Kumar Pachauri Dr. Ramesh Chandra Parida 35 Himansu Sekhar Fatesingh 10. Geology and Mineral Resources of Dhenkanal District Jayant Kumar Sahoo 37 11. Brahmagupta’s Geometry Er. Mayadhar Swain 41 12. The Worst and The Best Deba Datta 44 13. Quiz: Digestion & Absorption Anupam Mohanty 45 14. Recent News on Science & Technology 46

MAY-2020 1. Editorial : Covid-19 Pandemic Er. Mayadhar Swain 2 2. Telepathy Prof. B.B. Swain 4 3. Lidar Remote Sensing Er. Prasanta Kumar Patra 8 4. Why is Space Debris is a Threat to Us? Debi Prasad Mishra 10 Sanjay Vasanth 5. Some Recent Discoveries of Chemistry Anupam Mohanty 16 6. Selfish Gene Dr. Taranisen Panda 18 Dr. Rajballav Mohanty 7. Animal That Does Not Breathe Discovered Prof. Ramesh Chandra Parida 21 8. Rotavirus Prof. Prafulla Kumar Mohanty 23 9. Covid-19, A Lesson for Man to Think about Nature Biswajit Panda 27 and Environment 10. Sea Top Solar Power Plant Er. Ramesh Chandra Sahoo 31 11. International Year of Plant Health 2020 S. Routray 34 12. Innovation to Arithmetic Progression Birendra Kumar Acharya 41 13. Shanti Swarup Bhatnagar Awardee Mathematician Dr. Sadasiva Biswal 43 14. Quiz: Energy Girisha Chandra Tripathy 44 15. Recent News on Science & Technology 47

JUNE-2020 1. Editorial : Mangroves - A Unique Biodiversity Er. Mayadhar Swain 2 2. Environmental Hazards on Biodiversity Dr. Bijay Ketan Patnaik 4 3. Telepathy: Part-II Prof. Bipin Bihari Swain 7

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Subject Author Page 4. Styrene Gas Toxicity Dr. Manas Ranjan Senapati 12 5. Eco-Tourism Visa-a-Vis Biodiversity in Chilika Lagoon S.S. Rath 13 Subhalaxmi Rath 6. Lakhary Valley: A Rich Source of Biodiversity Dr. Pradipta Kumar Sarangi 19 7. Bandhavgarh: The Heaven of Tigers Prof. Prafulla Kumar Mohanty 21 8. Health, Environment and Climate Change Basanta Kumar Das 24 9. Covid-19 Vaccine Dr. Dwijesh Kumar Panda 26 10. Novel Coronavirus Vaccine: How Long More? Nikunja Bihari Sahu 29 11. Lise Meitner and Otto Hahn (The Discovery of Nuclear Fission) B. Sahoo 32 H.C. Rai Dr. P.K. Pujapanda 12. An Unmatched Talent Called Alan Turing Dr. Bijay Kumar Parida 39 13. Quiz: Biodiversity Utkal Ranjan Mohanty 45 14. Recent News on Science & Technology 47

JULY-2020 1. Editorial : Hubble at 30 Er. Mayadhar Swain 2 2. The Mysterious Concept of mass - I Dr. Bijay Kumar Parida 4 3. Disinfectants Dr. Manas Ranjan Senapati 9 4. Tricks of Trigonometry Birendra Kumar Acharya 11 5. Policy Issues on Global Warming and Climate Change Dr. Bijay Ketan Patnaik 13 6. Mahendragiri- The Lesser Known Natural Heritage Dr. Sundara Narayana Patro 18 Site on Eastern Ghats 7. Coronavirus and Herd Immunity Basanta Kumar Choudhury 23 8. Viruses Exist in a Gray Area between Chemistry and Life Dr. Dwijesh Kumar Panda 26 9. Locust Menace Dr. Taranisen Panda 28 Dr. Raj Ballav Mohanty 10. Science of Yoga Dr. Choudhury Satyabrata Nanda 34 11. Hepatitis B: A Serious Killer Prof. Prafulla Kumar Mohanty 38 12. Lise Meitner and Otto Hahn- Part II B. Sahoo 41 (The Discovery of Nuclear Fission) H.C. Rai Dr. P.K. Pujapanda 13. Quiz: Covid 19 Birat Raja Padhan 46 14. Recent News on Science & Technology 47

AUGUST-2020 1. Editorial : Power of Atom Er. Mayadhar Swain 2 2. Alarming Warming up of Oceans Nikunja Bihari Sahu 4 3. Bharat Stage Emission Standards Sthitaprangya Chand 6 Gunanidhi Sahoo

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Subject Author Page 4. Palindromic Number Saroj Kumar Mohanty 10 5. Ramanujan’s Nested Roots Er. Mayadhar Swain 13 6. Fossils and Plant Fossil Formation Basanta Kumar Choudhury 14 7. DNA- The Secret of Life Prajnaparamita Mishra 17 8. Asparagus S.P. Mishra 22 A.K. Padhiary 9. Garlic - An Age-Old Culinary and Health-Aid Prof. Gopendra Kishore Roy 25 Dr. Pragyan Roy 10. Vanishing Glow Worms Dr. Raj Ballav Mohanty 29 Dr. Taranisen Panda 11. Enzymes in Food Industry Er. Timira Mishra 31 12. Dhenkanal Science Centre and Kapilas Science Dr. Jayanta Sthanapati 33 Park turn Twenty-Five 13. The Mysterious Concept of Mass - II Dr. Bijay Kumar Parida 39 14. Quiz: Forestry Dr.Sanjeeb Kumar Das 45 15. Recent News on Science & Technology 46

SEPTEMBER-2020 1. Editorial : Human Exploration to Mars Er. Mayadhar Swain 2 2. Smog: Its Effects on Environment L.M. Das 4 3. Forest Scenario: Then and Now Dr. Bijay Ketan Patnaik 9 4. Mathematical Inquisitive Through The Ages Rama Sankar Rath 12 5. Random Walk to Abel Prize Dr. Sunita Chand 15 Dr. Ramesh Chandra Parida 6. Rare Solar Eclipse of the Year Nikunja Bihari Sahu 18 7. Nanotechnology to Detect Sars-Cov-2 Susmita Mohapatra 20 At the Early Stage of Infection 8. Hand Washing Dr. Pranab Kumar Ghosh 25 9. E- Cigarette Dr. Taranisen Panda 29 Dr. Raj Ballav Mohanty 10. Science Against Superstitions Ansuman Dash 34 11. Yellapragada Subbarow: A Pioneer Medical Scientist Prof. Guru Prasad Mohanta 36 12. Dealing Children with Behaviour Problem (Part-I) Dr. (Mrs.) Pritishri Parhi 39 13. Medical Marvels Dr. Dwijesh Kumar Panda 42 14. Quiz: Genetics Mr. Anupam Mohanty 45 15. Recent News on Science & Technology 46

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Subject Author Page OCTOBER-2020 1. Editorial : Chemical Accidents Er. Mayadhar Swain 2 2. Existing Legal Frame Work on Climate Change in India Prof. Pramod Chandra Mishra 4 3. Water Scarcity: An Impending Pandemic Soumya Kar 9 4. Green Buildings Er. Ramesh Chandra Sahoo 14 5. Sunset Sky on Different Planets Prof. Bipin Bihari Swain 18 6. Frustum Saroj Kumar Mohanty 22 7. Chemistry Behind Cholesterol Dr. Ashis Kumar Jena 24 8. Stories of Genes: DNA, Genes, Chromosomes G.B.N. Chainy 27 And Genomes 9. Why Being Slow is Fast, in The Race For Vaccine Atulya Kumar Jena 31 Development? 10. Some Notorious Diseases in The Recent Past Prabhukalyan Mohapatra 34 11. Dealing Children with Behaviour Problem (Part-II) Dr. (Mrs.) Pritishri Parhi 35 12. Ageing-The Inevitable Biological Process Prof. Gopendra Kishore Roy 39 Dr. Pragyan Roy 13. Bibha Chowdhuri: An Indian Woman Scientist Dr. Sadasiva Biswal 44 14. Quiz: Animal Morphology Prof. Prafulla Kumar Mohanty 45 15. Recent News on Science & Technology 47

NOVEMBER-2020 1. Editorial : Climate Change and Carbon Neutrality Er. Mayadhar Swain 2 2. The Mysterious Concept of Mass - III Dr. Bijay Kumar Parida 4 3. Mineral Development and Ecological Sustainability Dr. Sundara Narayana Patro 7 4. Behaviour Development of The Child Dr. (Mrs.) Pritishri Parhi 12 5. Let Us Find L.C.M. Dr. Archana Panigrahi 15 6. A Brief History of Indian Math-Magicians Purusottam Sahoo 17 7. O Mighty Planet Venus Vaibhavi Karthik 24 8. One Interesting Series of Nilakantha Er. Mayadhar Swain 25 9. Dragonfly: The Hawk of the Insect World Dr. Raj Ballav Mohanty 26 Dr. Taranisen Panda 10. Stories of Genes: II The Genetic Code G.B.N. Chainy 27 11. Mask: A Need For Survival Dr. Pranab Kumar Ghosh 32 12. Humus - The Skeleton of Soil Meenakhi Prusty 37 Monika Ray 13. Quiz: Covid-19 Pandemic Dr. Bibhuti Narayan Biswal 43 14. Recent News on Science & Technology 45

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