APEC Youth Scientist Journal Vol. 5

TIDAL ENERGY IN KOREA

∗ Jeong Min LEE 1

1 Goyang Global High School, 1112 Wi city 4-ro, Ilsandong-gu, Goyang-si, Gyeonggi-do, Korea 410-821

ABSTRACT

Tidal energy is one of the few renewable energy resources Korean government is planning on to implant in Korean Peninsula. Due to its continuity and environmental friendliness, tidal energy is getting its attention as appropriate alternative energy for Korea that can replace conventional fossil fuels. On the other hand, while Korean government is pushing forward to build tidal plants using Korea’s geographical advantages following the construction of tidal plants, many locals are holding demonstrations in order to stop tidal plants from being built. These disputes are holding off government’s original plan to construct tidal plants in Incheon Bay area. In this study, concept of using tidal energy and various methods will be introduced, followed by Korea’s geographical conditions for constructing tidal power plants. Concerning construction of tidal plants in Korea, problems regarding the issue will also be covered. This will provide current status of tidal energy as renewable resource in Korea, and how it will change to impact the country.

Keywords: tidal power, geographical advantage, tidal plant sites, ecological impact, conflict

∗ Correspondence to : Jeong Min L EE ([email protected])

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1. INTRODUCTION Energy we use to produce electricity and heat has brought great changes on how we live today. However, nowadays despite successful contribution to improvements of human lives, conventional resources are losing its stature for creating many problems to global society. As a result of the problems brought by traditional energy resources such as climate change, many countries are now turning their attention to renewable energy resources. As technological development occur in fields of energy resource, renewable energies are getting its attention for their environmental friendliness and continuity of resources. Korea also has adapted to this global trend in energy consumption. Former president Myung-Bak Lee presented the National Strategy for Green Growth, which set its goal in enhancing people’s quality of life through eco-friendly growth engines and contributing to international efforts to prevent climate change. Also Korea signed an agreement with Global Green Growth Institute in January 17 th , 2013, showing its will to continue pursuing the goal of green growth in the future. Considering Korea’s promises to continue green growth, what kinds of renewable energy will be actually beneficial to Korea? While many countries have their own landmarks, Korea is said to have a unique geographical feature which makes the country suitable for tidal power generation system. Therefore through this research, we will be able to find out what tidal energy is and what is special about Korean ocean that makes it perfect place for the one of the biggest tidal power plants in the world. Along with benefits of having tidal power plants in Korea, we will tackle some problems that contradict the original purpose of using renewable energy and what tidal energy will be like in the future.

2. RESEARCH

Tidal energy is one form of hydropower energy produced by ocean water during the rise and the fall of tides. Tidal power generator uses energy during those certain time to convert them into electricity, to be used in many other forms. In the process, turbines convert potential energy of tides into electrical energy. There are currently three main types for harvesting tidal energy; tidal streams, barrages, and tidal lagoons.

(1) Tidal Streams Tidal stream is a form of generating electricity by spinning a turbine underneath the ocean. Tidal stream uses kinetic energy of tides to produce electricity. This method can be

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divided into two ways. One method is generating turbine during the low tide (Figure 1). Flood gate is opened during high tide until it captures large mass of ocean water. As low tide creates height difference between captured water and the o cean water , the gate releases captured water in order to turn the turbine, thereby generating electricity. Another way is spinning the turbine during high tide in which the process is complete opposite of the former method . When building tidal streams, app ropriate method has to be chosen regarding ocean conditions in the nearby area. It is possible to generate electricity in both tides, yet it also depends on the ocean conditions ; taking account of whether it is efficient or not. Currently, tidal stream method is the most used method of producing energy from tidal power, and it is being used in France, China, and Korea.

Figure 1: Process of tidal stream during low tides (top: filling water, bottom: generation)

(2) Barrages Tidal barrage uses a dam to produce energy from ocean tides. This system makes use of potential energy of difference in height in low and high tide. This process uses large dam called ‘barrage’ for holding tide water and then releasing them to spin the turbine. The process of tidal barrage is very similar to that of river dam. (Figure 2) First, the barrage gates are opened to take water in as the tide rises. At high tide, barrage gates are closed to create what is similar to water lagoon. Then a s the tide lowers, water is released through bar rage turbines, creating energy. This barrage can be constructed in tidal bays, and across tidal estuaries. As of now, there are tidal barrages operating in France and Canada, proving its effectiveness for nearly 40 years.

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Figure 2: Process of tidal barrage

(3) Tidal Lagoon System of tidal lagoon produces energy by creating tidal lagoon. Tidal lagoon is a large amount of ocean water enclosed by normally man-made barrier. The process of generating energy is much like the process of barrier. However in tidal lagoon, energ y can be generated continuously because turbine can work as the water is being filled and emptied (Figure 3) . Also tidal lagoon can be constructed along the coastline, providing wider area for construction. Yet the actual amount of energy production is minimal compared to other methods. Because of this relative inefficiency, there is n o tidal lagoon currently running, however China is planning on constructing tidal lagoon near the border of North Korea.

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Figure 3 : P rocess of tidal lagoon (note that power is generated both in high tide and low tide)

KOREA: PERFECT PLACE FOR TIDAL POWER ENERGY As shown above, there are several ways to produce electricity from tidal energy . However, only few places can actually run tidal power plants successfully , because extracting sufficient amount of energy from tides requires power plants to be built in a specific area in which tides can create enough energy to be beneficial . There are few bu t very essential geographical conditions which make a land an efficien t place for producing tidal energy.

Big gap between high tide and low tide Tidal plant uses poten tial energy created between ocean tides. Therefore bigger gap between high tide and low tide means more potential energy a vailable for energy production.
Large surface area in which tides can come and go Quantity of electricity produced by tidal plant is determined by the volume of water which goes through turbines. Large surface area for tides yields large volume of water to activate the turbine.
Places for shorter dams for economic construction This factor determines the efficiency of a tidal plant in its construction . If length of a dam for a tidal plant is short relative to its size, it requires less money for construction and maintenance, compared to its high energy production.

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Because of these conditions, there are actually only few places in the world that are adequate for production of electricity through tidal power plants. (Figure 4)

Figure 4: Areas colored in dark blue are regions with high potential of tidal energy resources

Figure 5: Tide measurements in Shiwa power plant. difference of sea level goes up to 10 meters As seen o n Figure 4, Korea is considered as one of the few countries with the geological feature th at is suitable for tidal energy. Especially the western coastline of Korean

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Peninsula holds areas appropriate for tidal plants. First, difference between h igh and low tides are very big ; the height of two tides changes up to 10 meters. This allows tidal plants to harvest both more potent ial and kinetic energy for each tide. Also, Korean west coast has the geographical feature called ‘rias cost.’ Rias coast is geographical feature of a coast with irregular and curve-like coastl ines. This feature provides bigger surface area to use tidal energy, and also to have relatively shorter dam because of its curve-like formation . As seen above in the context, Korea has its geographical advantage that makes it apropriate place for constructing tidal power plants, especially in Incheon Bay area, where all of these conditions fits for tidal plant. Due to these conditions, Korea has been investing on researchs for finding better place for tidal plant sites.

CURRENT STATUS OF TIDAL ENERGY IN KOREA Korea was seen with it potential for effective tidal plants since the 1920s. In 1929, the Japanese Government General of Korea ran several investigation projects in Incheon Bay, to plan an Incheon Bay tidal plant. Research for tidal plant sites increased especially after the oil shock in 1970s. Korea Ocean Research & Development Institute (KORDI) operated research projects in 1974 and 1978 and had located ten sites for possible construction of tidal plants along the western coastline. As sudden changes in crude oil market and environmental crisis in energy production increased, 'Clean Development Mechanism (CDM) ' got its attention and as a result, Korea is now turning their attention to tida l energy. After several investigations, Shiwa Tidal Plant (capacity of 254MW) was completed in November, 2011 , and five other sites are being considered as the next tidal plant s in Korea.

 Shiwa Tidal Power Plant (Figure 7)

Figure 6: Full view of Shiwa Tidal Power Plant

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Shiwa tidal plant is Korea’s the only tidal plant, located in Shiwa, Gyeong-gi province. This tidal plant started its construction in December, 2004, and was completed in 2011. Since then, Shiwa Tidal Power Plant is the largest energy-producing tidal plant in the world, with capacity of 254MW. This project was initially operated to reduce Carbon emission in Korea and to secure stable amount of energy. Shiwa tidal plant uses tidal stream method, producing electricity only during the low tide. This plant has 10 turbines (Figure 6) and 8 water gates which are opened to release ocean water during the low tide. In the long run, the Shiwa Tidal Power Plant is expected to contribute in cutting down around 85million dollars in crude oil import and reduce 315,000 tons of Carbon Dioxide emission every year. In addition to energy gain from the tidal plant, municipality is planning to set up a tour belt for sight-seeing and educational purposes.

Figure 7: Model of Shiwa tidal plant turbines

Besides Shiwa tidal plant, there are many potential tidal plant sites in Korea (Figure 8).

Ganghwa (420MW) Incheon Bay (1,140MW) Garorim Bay (520MW)

Following sites are some of the places that would produce more energy than any other tidal plants that exist in the world as of now. Because of these benefits, Korean government is trying to build efficient power plants for self-sufficiency of electricity of the country in the future. However, despite these geographical advantages of Korean tidal plant sites, local communities and NGOs still disagree with the idea of turning those sites into actual tidal plants.

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Figure 8: Locations of potential tidal plant sites

PROBLEMS WITH TIDAL PLANTS IN KOREA In spite of environment benefits tidal energy resource have, since the time Korean government proposed their big tidal plant construction projects for the near future, there have been controversies arousing on whether tidal plants are truly beneficial to the environment.

(1) Ecological Impact of Tidal Plants While new projects to construct tidal power plants have bigger capacity than that of existing Shiwa tidal plant, they bring out a problem that threatens wildlife on wetlands t hat are protected by Korean law because of inhabitation of rare species in the area. For example , as seen on Figure 9, current plan for Incheon Bay Tidal Power Plant will invade 24km 2 of ‘Jangbongdo Wetland Preservation Area ’ if the project is put into action. ‘Jangbongdo Wetland Preservation Area’ is the biggest preservation area in Korea, designated in 2003, for its marine life, habitat of rare waterbirds, and its unique geomorphology. In addition, Ganghwa Tidal Power Plant is planned to be built right next to the ‘Ganghwa Tidal Flat Black-Faced Spoonbill Habitat ,’ which is South Korea’s largest Natural Heritage Site designated in 2000. This site is being used as settlements to thousands of migratory birds, some of them known to be endangered.

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Figure 9: Map of two proposed tidal plant sites, notice that each plant sites are crossing over the borders of important tidal flats in Korea As of now, many environmentalists and non -government organizations are criticizing Korean government’s act of harming the natural habitat. Also even the municipality of Incheon is strongly opposi ng against constructing tidal plants in its city and changing the environment. However, Korean government is in favor of conducting further tidal plant projects, and Ministry of Lan d, Transport and Marine affairs (MLTM) , which has the right to control over national heritage and wetland preservation areas, is planning on reducing the size of wetland preservation area to the size that will not cross the tidal plant sites. It is not sure to say that the ecosystem and environment around the future tidal plant sites will be ‘damaged’ because of these projects. Yet, because of alteration of environment due to tidal power plants, it is sure to say that they will certainly ‘change’ in such unexpected manner that wild life and rare species of anim als will lose their habitats.

(2) Impact in Local Communities near Tidal Plants Concern for local communities following the change of environment due to tidal plants is loss of long term jobs. In the areas of potential tidal plant areas, wetlands and mud flats provide number of jobs to local populations regarding fishery and tourism. If these environments are dam aged due to construction of power plants, sites for local fishery will lose its economic efficiency , not only in the areas directly affected by tidal plants, but also places near the sites as well.

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(3) Current Status Due to strong objections form NGOs and local communities, most of the plans for tidal plant in Korea are held off. However recently, Ganghwa and Garorim Bay tidal plants are starting to push forward its construction plans. As of now, ‘Garorim Tidal Power Generation’ company will submit environmental effects evaluation to the Ministry of Environment in order to push forward its plan to construct a plant in Garorim Bay. In addition, Korean government included construction of Ganghwa tidal plant in its Demand Supply Program. Stimulated by the advent of government and corporations’ plan to construct new power plants in Incheon area, disputes between opposing sides are getting bigger than ever. Even with these massive debates and disputes about the issue of tidal energy, it is expected that government will try to force its plan to build more tidal plants in Korea.

FUTURE FOR TIDAL ENERGY According to ‘Korea Electro-technology Research Institute’ in 2012, only 4% of total electricity produced in Korea is derived from energy that had been made in the country. While countries such as the US and China produce 90% of total energy use in their countries, Korea imports almost all of energy from outside countries. This could bring a critical problem in the future, when energy resource in the world becomes scarce. Therefore Securing sufficient energy resource is very essential task for Korean government, and probably that is the reason why Korean government is pushing so hard to build more tidal power plants in Incheon area. Korea is in need of energy. Korea is in need of renewable energy. Therefore tidal energy can be one of the alternatives to conventional energy resources. However tidal plants can bring environment damage to landscape in ecology of nearby area. Therefore, Korean government should not push its plans but really consider environmental effect also. Considering this matter, debates between two sides are very advisable. If constant attention is given to tidal energy, additional improvement of technology and policies can lead to more

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3. REFERENCES

1. Yekang Ko and Derek K. Schubert, "South Korea’s Plans for Tidal Power: When a “Green” Solution Creates More Problems", NAPSNet Special Reports, November 29, 2011, http://nautilus.org/napsnet/napsnet-special-reports/south-koreas-plans-for-tidal- power-when-a-green-solution-creates-more-problems/ 2. “Green Growth in Action: Korea”, OECD, http://www.oecd.org/korea/greengrowthinactionkorea.htm 3. Kwangsoo Lee and Jinsun Park, “tidal power generation in Korea”, International Journal of Ocean Engineering and Technology, September, 2012 4. Yoengbin Kim, “Incheon City resists tidal power generation at Incheon Bay and YoungHeung thermal power plant Expansion”, Asia Economy, February 4, 2013, http://view.asiae.co.kr/news/view.htm?idxno=2013020415461806450&nvr=Y 5. Kwangsoo Lee, “Tidal and Tidal Current Power Study in Korea”, Coastal Engineering Research Department KORDI, May 2006, http://www.energybc.ca/cache/tidal/KOREA.pdf 6. Se Woong Ahn and Hi Sun Lee, “Reducing Plan of Environmental and Social Conflicts for Tidal Power Plant through the Analysis of Environmental Impact”, Jun 19, 2012 7. “Energy Source: Tidal Power”, Pembina Institute, http://www.pembina.org/re/sources/tidal 8. Tae young Kwak, "Tourism belt from SiHwa Lake Tidal Power Plant to DaeBoo Ialand ", Ansan Tomorrow Newspaper, September 5, 2011 9. Tae Gu Park, "Carrying out an environmental effects evaluation for GaRoRim Tidal Power coming May", Joongdo Daily News, Febreuary 26, 2013, http://www.joongdo.co.kr/jsp/article/article_view.jsp?pq=201302250255

Jeong Min LEE

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