Renewable Energy for Development
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Renewable Energy for Development S TOCKHOLM ENVIRONMENT INSTITUTE – N EWSLETTER OF THE ENERGY PROGRAMME SEI • June 2000 Vol. 13 No. 2 ISSN 1101-8267 Cuba’s Transition away from Fossil Fuels by Dr. Antonio Valdes, Agency for Science and Technology, Havana, Cuba In recent years, Cuba has increased efforts to exploit renewable energy sources and reduce its dependence on oil. Wind, solar, and biomass offer a variety of renewable options that are well suited to the Caribbean climate. This article discusses Cuba’s current energy system, with an emphasis on electricity generation, and describes plans for expanding and improving Cuba’s emerging portfolio of renewable energy options. uba is a Caribbean island with a tropical climate, a landmass of 110,000 km2 and a population of 11 mil- C lion. The economy is agriculturally based, with major export products being sugar, tobacco, coffee, and citrus fruits. Nickel mining and tourism are also major components of the economy. The sunny and windy Caribbean climate and Cuba’s special history of sugarcane production suggests many oppor- Solar PV Installation in rural Cuba tunities for tapping renewable energy resources. Before the fall of the Soviet Union, subsidised oil and pref- erential trading relations with the communist world discour- homes (see photo). There exist approximately 1000 PV instal- aged Cuba’s renewable energy development. In the post-So- lations ranging in size from 10 W to 90 kW, for a total installed viet era, Cuba has had to look for new economic alternatives, capacity of 202 kW. Some of these PV installations have spe- including new sources of energy. The government formed the cial social significance, such as those at the 225 General Prac- Cuban National Program for the Development of Natural En- titioner Doctor Dispensaries located in the sparsely populated ergy Resources, whose objectives are to reduce petroleum de- inland hills. A typical installation is a 400 W system that pow- pendence by improving efficiency and developing other natu- ers twelve fluorescent lamps, a TV set, a radio transmitter, three ral energy resources. medical instruments, and a small refrigerator for vaccines. Most of the population (approximately 95 %) has access to Continued on p. 2 electricity. Table 1 lists the current shares of different sources in electricity production and installed generating capacity. Oil remains the primary fuel in the electricity mix. The existing installed capacity in the sugar cane sector provides the best near- In this issue: term option for replacing oil. Other renewables, such as wind, Cuba´s Transition away from Fossil Fuels hydro, and solar can play an important role as well. Dr. Antonio Valdes ....................................................................... 1 Solar Energy Sudan´s Renewable Energy Options: Solar insolation in Cuba averages 5 kWh/m2/day with little sea- Power for Water and Living Abdeen Mustafa Omer ................................................................. 4 sonal variation, and is currently used for both Photovoltaic (PV) and solar thermal applications. Solar thermal is used for water Non-Conventional Energy Sources: heating in the residential sector and in larger social institutions, An Appraisal of Policies, Goals, and Achievements in India Dr. Atiqur Rahman ....................................................................... 6 such as nurseries, hospitals, and schools. PV systems are used in remote rural areas with poor access to the national electricity Global Dialogue on Natural Resources at Expo 2000 ................... 8 grid, including hospitals, schools, and tourist sites as well as Renewable Energy for Development, June 2000, Vol. 13, No. 2 1 continued from p. 1 resources in Cuba. The sugar industry in Wind Power Cuba goes back hundreds of years and In Cuba, wind energy is today mainly Cuba has been one of the world’s lead- used for water pumping, with over 6 700 ing sugar producers since the 1800s. wind-powered pumps currently in opera- Sugar cane plantations cover one-fourth tion. Wind has not yet been significantly of the arable land in Cuba, and Cuba ac- exploited for power generation. counts for 10 % of world sugar cane pro- At present there exist only two sys- duction. In addition to raw sugar, Cuban tems – a system of two 225 kW turbines enterprises produce and utilise many on Turiguano Island (see photo) – and an valuable cane co-products for feed, food, experimental 10 kW turbine at Cape Cruz. energy and fibre. At present, there are 156 At Turiguano Island, there are plans to sugar factories, 16 sugar refineries, 13 expand to 1000 kW – enough capacity to alcohol distilleries, 10 Torula yeast plants, supply 40 % of the island’s electricity 5 pulp and paper plants, 7 particle board needs and displace 430 tonnes of fuel oil plants, and 160 animal feed production per year. A recent survey at over 20 sites, plants. primarily in coastal regions, concluded Table 3 illustrates the development of that there are excellent possibilities to cogeneration within the Cuban sugar in- Wind Installation in rural Cuba develop wind power at these sites. dustry. Installed capacity doubled be- tween 1959 and 1990, while electricity Hydropower mass resources. There exist a variety of generation tripled. Sugar cane bagasse Hydropower plants are classified by their readily available sources in Cuba, includ- and sugar cane trash already provide a rated capacity into one of four regimes: ing agricultural residues such as sugar significant amount of biomass for elec- micro (< 50 kW); mini (50–500 kW); cane bagasse, rice husks, and coffee tricity production in Cuba, but the poten- small (500 kW–5 MW); and large (> 5 residuals; tree/forest residuals such as tial is much higher with advanced coge- MW). Cuba’s current installed hydro- sawdust and coconut shells; and various neration technologies. Most sugar facto- power capacity amounts to nearly 30 animal wastes. ries in Cuba, as elsewhere in the devel- MW, which in 1998 produced 23 GWh oping world, can produce about 15-30 of electricity. The number of hydropower Sugar Cane Biomass kWh per tonne of cane. If all factories plants in the three smaller categories are Residuals from the sugar cane industry were fitted with Biomass Gasifier-Com- given in Table 2, accounting for about represent by far the most important bined Cycle systems, 400–800 kWh of half of total hydro capacity in Cuba. source of current and potential biomass electricity could be produced per tonne These plants are generally used to serv- ice 200 small, isolated, rural villages with over 7 000 houses and 24 000 inhabit- Table 1: Electric Power Fuel Shares in Cuba ants. The plants also provide power to 503 social service institutions. There are also Electricity Production Installed Capacity 6,6 MW under construction, capable of supplying an additional 38 GWh per year. Petroleum 87 % Estimates of Cuba’s hydro potential that Diesel 1 % remains to be exploited range from 50 Oil 72 % MW (210 GWh/year) to 400 MW (1 000 Cane 5 % 19 % GWh/year). Hydro 2 % 1 % Gas 6% 6% Biomass Resources Biomass resources should be divided into residues or dedicated resources, the lat- Table 2: Smaller-scale Hydroelectric Plants installed in Cuba ter including fuelwood and charcoal from forest resources. Approximately three Number of Number Number of Installed million m3 of fuelwood are consumed per Type of hydro plants connected isolated power year, mainly for cooking. To avoid re- installation Installed to grid installations (kW) source depletion, Cuba is currently un- Microplants 138 9 129 3 033 dergoing a reforestation program of Miniplants 32 12 20 4 030 130,000 ha. Biomass residues are more Small plants 5 5 – 7 310 economically exploitable and more en- Total 175 26 149 14 373 vironmentally benign than dedicated bio- 2 Stockholm Environment Institute of cane, enough to satisfy all of Cuba’s biogas plants. Pig and cattle farming are current electricity demand. likely sources for smaller-scale biogas; in Cuba these provide feedstocks for 75 Alcohol production biogas installations. Of this total, 60 units Cuba has 13 alcohol distilleries with ca- are of fixed dome design with volumes of pacity of 200–1200 litres/day that use cane 8 to 70 m3, and 15 units are of plastic tu- molasses as feedstock, for a combined ca- bular design with volumes ranging from pacity of over 1,5 million hectolitres. The 12 to 24 m3. The solid waste from biogas alcohol is used for a variety of applications, plants adds economic value by providing mainly for medical purposes and rum pro- valuable fertilisers as by-products. duction, the latter of which accounts for 74 % of domestic use. Use of alcohol fu- Economic Potential els, once common in Cuba in the 1940s Rail link to the Urbano Noris sugar of Cane Resources and 1950s, all but disappeared with the factory in Cuba An example from a typical sugar factory availability of cheap oil. The current cir- in Cuba illustrates the economic value of cumstances suggest that Cuba should con- attempts to better utilise the cane biomass sider expanding production for use as a for cooking in many rural areas. Anaero- resources available. Table 4 gives the quan- transportation fuel, but this option has not bic digesters producing biogas (methane) tity, estimated economic value-added, and yet been pursued. Blending with gasoline offer a sustainable alternative fuel for oil equivalence for the major co-products would also have direct environmental cooking that is appropriate and economic from a factory producing 500 tonnes of advantages by substituting for lead as an in rural areas. In Cuba, there are currently sugar per day. The additional products octane enhancer. over 200 installed biogas units, covering have an estimated value of 6.55 million a wide range of scales appropriate to fam- USD, an increase of 33% over the value Biogas ily, community, or industrial uses.