By Jungdo Kim, Director of the ARC Center
On February 13, despite fierce opposition from civil society, the environmental impact assessment for the 150MW gas power plant pushed by Korea East-West Power (EWP) in Dongbok-ri, Gujwa-eup, was officially passed. With only the approval of the implementation plan and building permits remaining, the project has cleared nearly all administrative hurdles, meaning construction could begin at any moment. EWP has already expressed its clear intent to proceed, stating on social media that the institutional foundation for the project is now firmly in place.
While the construction of EWP’s gas plant is being treated as a fait accompli, the voices of Jeju residents are only growing louder. This is because Korea Middle Power (KOMIPO) is also undergoing an environmental impact assessment for another 150MW gas plant in Samyang-dong, Jeju City. If both plants are completed, a massive 300MW of fossil fuel infrastructure will be added to Jeju’s power grid. We must soberly examine whether this is truly the right choice for Jeju’s future.
Massive Greenhouse Gas Emissions: A Direct Collision with ‘2035 Carbon Neutrality’
The first and most immediate problem is greenhouse gas emissions. According to the environmental impact assessment, the two planned 300MW gas plants are expected to emit up to 1.1 million tons of carbon dioxide annually. This is equivalent to the emissions of 520,000 cars over a year, requiring approximately 160 million pine trees to absorb.
Even more critical is the disconnect from Jeju’s overarching policy goals. As of 2021, Jeju’s direct greenhouse gas emissions stood at approximately 4.327 million tons of CO2eq. This means that the maximum emissions from these two gas plants alone would account for a staggering 25% of Jeju’s total emissions.
As long as Jeju holds onto its ambitious goal of ‘2035 Carbon Neutrality,’ building these plants is a self-contradictory move. Furthermore, in the case of Samyang-dong, reports indicate that air quality standards for fine dust and ozone may be exceeded once the plant is operational. Dongbok-ri also faces inevitable air quality degradation, exacerbated by the presence of nearby incinerators and landfills.
The ‘Must-run’ Shackle: Hindering the Transition to Renewable Energy
In the electricity sector, ‘must-run’ units are power plants that must remain operational to maintain grid stability, even when supply exceeds demand. The problem arises when these plants stay on while there is surplus electricity; the government then forcibly stops renewable energy production (solar and wind) to balance the grid—a process known as ‘curtailment.’
One might think that having more electricity is always better, but if supply significantly exceeds demand, the grid frequency becomes unstable, potentially damaging appliances or leading to a widespread blackout.
According to EWP’s plans, the Dongbok-ri plant is expected to produce an average of 626,000 MWh of electricity annually. This is about 70% of the output of the Namjeju Combined Cycle Power Plant in Seogwipo. As gas power increases, renewable energy will be forced to shut down more frequently, effectively causing Jeju’s energy transition to backslide.
Overestimated Demand and the Availability of Technical Alternatives
EWP justifies the need for these plants by citing increasing power demand and grid stability. However, in the summer of 2024, Jeju’s power reserve margin remained very stable at 16.2% to 22.8%. Despite this, the 11th Basic Plan for Electricity Supply and Demand set Jeju’s peak demand for 2038 at 1,644 MW and raised the target reserve margin to 34%—an excessively high estimation.
The gap created by the retirement of 255 MW of aging power plants by 2030 can be filled with existing alternatives. The recently completed 3rd HVDC (High Voltage Direct Current) line has increased Jeju’s power supply capacity from the mainland to 600 MW, and 188 MW of long-duration Battery Energy Storage Systems (BESS) are scheduled for deployment by 2028.
The issue of ‘inertia’—the ‘buffer’ that prevents the grid from collapsing during sudden shocks—can also be solved. While this role was traditionally played by the rotating mass of large fossil fuel turbines, it can now be handled by synchronous condensers or by repurposing turbines from retired plants.
Furthermore, ‘Grid Forming’ technology, which provides virtual inertia through inverter control, is gaining global attention. Countries like Spain, which have experienced major blackouts, are choosing to increase renewable energy shares by combining ESS with Grid Forming technology instead of building more fossil fuel plants.
The ‘Greenwashing’ of Hydrogen Co-firing and Economic Irrationality
The logic of mixing ‘green hydrogen’ with gas is a key justification for these new plants. However, current technology shows that a 15% hydrogen blend only reduces $CO_2$ emissions by about 5%. Even at a 50% blend, the reduction is only 24%. Ultimately, this means Jeju will be burning fossil fuel methane and emitting carbon for a long time before full hydrogen technology is ready.
Specifically, to obtain enough green hydrogen for 100% hydrogen firing through renewable energy, it would require 2.7 GW of offshore wind and an investment of over KRW 20 trillion. Is it rational to spend KRW 20 trillion for a 300 MW power facility? It would be far more economical and logical to use that 2.7 GW of renewable energy directly and invest in securing the necessary flexibility resources (like storage).
Inflated Job Claims and the Risk of ‘Stranded Assets’
EWP promotes the project by citing 210,000 man-days of labor and a production inducement effect of KRW 960 billion. However, these are temporary effects limited to the construction phase, and a significant portion of that capital flows to out-of-province equipment suppliers. EWP’s own estimate for the actual contribution to the local economy is only about KRW 66.8 billion. Long-term professional roles will likely be filled by personnel from the mainland, while local hiring will likely be limited to unstable, low-skilled positions.
Moreover, gas power plants are bound to face declining profitability due to rising fuel costs and carbon taxes. Volatile international relations continue to drive up gas prices. There is a high risk that these plants will become ‘stranded assets’—becoming obsolete before their lifespan ends—leaving the public to foot the bill through tax subsidies or increased electricity rates.
Moving Beyond the Past Toward a Leading Green Civilization
Jeju already possesses innovative alternatives to outdated gas power plants.
First: ‘Time-shifting energy’ tailored to Jeju’s consumption patterns. Jeju lacks large industrial factories, so demand peaks between 6 PM and 9 PM. Currently, Jeju often has surplus solar power during the day that gets curtailed. Storing this surplus in large-scale ESS and using it during evening peaks could largely eliminate the need for new gas plants.
Second: Implementing ‘Grid Forming’ technology. While heavy steel turbines provided physical inertia in the past, software-driven Grid Forming technology is now the global standard for stabilizing grids. Jeju, with its high share of renewables, is the most optimized location in Korea to realize this technology.
Third: Jeju’s own energy plans prove it is possible. According to the ‘7th Basic Energy Plan’ currently being established by Jeju Province, the goal is to build 1.4 GW of solar, 5.6 GW of wind, and 488 MW of ESS by 2030. This scale is more than enough to fill the void left by retiring fossil fuel plants.
The June 3 Local Election and the Choice of Jeju Residents
It is technically and economically proven that new gas power plants are not a necessity. Ultimately, what remains is a matter of political will. Cities like Daejeon, Daegu, and Chungju have successfully scrapped power plant plans through the refusal of local governments. This issue also hinges on the will of the Jeju provincial government. It is not something to be watched idly as a ‘national plan.’
The local elections are only three months away. The 12th Basic Plan for Electricity Supply and Demand, to be announced at the end of this year, will inevitably reflect the philosophy of the new 9th municipal administration. In this election, we must vet candidates who oppose the construction of new gas plants and are committed to a true green transition. Candidates must not tether Jeju’s future to the fossil fuel past. Only the determination of candidates and the wise votes of residents can transform Jeju into a true leader in carbon neutrality.
This article was originally published in the 90th issue of Weekly Another Jeju by the Another Jeju Lab.