Wind Returns to Gapa-do After Turbines Fell Silent... Reviving the 'Carbon-Free Island' Dream [Energy Odyssey] (17)

III. The Dream of Electrification
Only Weeds Where the Wind Turbines Once Stood... Remnants of an Energy Self-Sufficiency Experiment Launched More Than a Decade Ago
Wind Power to Rise Again... Gapado RE100 Village Project Gets Underway
Building 6

Editor's NoteRecent supply chain crises caused by the war in the Middle East and the government's megaprojects have made energy more important than ever. South Korea faces the difficult challenge of simultaneously achieving energy security, carbon neutrality and economic growth, while relying on overseas sources for most of its primary energy. In this series of feature articles, reporters covering energy issues on the ground will examine a range of pressing concerns and explore possible solutions.

A marker inscribed “Gapa-do, an Eco-Friendly Island of Distinction” stands near the Gapa-do ferry terminal in Seogwipo, Jeju, on the 30th of last month. Gapa-do, which previously pursued a project to become energy self-sufficient, is once again seeking to transform itself into an eco-friendly energy island through a project to create an RE100 village combining wind and solar power with energy storage systems (ESS). Photo by Kang Nahum

On one side of Gapa-do's vast fields in Jeju, there was once a cluster of wind turbines built to supply electricity to the island. But when we visited the site on October 30, there were no giant blades or turbines converting wind into electricity. Only an empty lot remained where the turbines once stood. It is a reminder of Gapa-do's first experiment in energy self-sufficiency, launched more than a decade ago with the dream of creating a "carbon-free island."

Gapa-do, a small island covering 0.87 square kilometers, is about a 10-minute boat ride from Unjin Port in Daejeong-eup, Seogwipo, Jeju. It is known as one of the windiest places in Jeju. The sea stretches in every direction, and the wind sweeps freely across the island's low-lying terrain. The island's natural conditions were no coincidence in the decision to pursue a plan to generate electricity without fossil fuels by combining wind and solar power.

In the early 2010s, Gapa-do tested the potential of becoming energy self-sufficient through Jeju Island's Carbon Free Island (CFI) initiative. The plan was to combine two wind turbines, solar power and energy storage systems (ESS) to generate all the electricity the island needed. Over time, however, the generation equipment and power conversion systems began to break down, and the wind turbines, a key part of the system, were eventually removed in September 2024.

A walk to Gapa-do Power Plant, which supplies the island's electricity, revealed a reality at odds with the name "energy self-sufficient island." The island's main source of power is currently diesel generators that run on diesel fuel. More than 30-year-old diesel power generation equipment now sustains the daily lives of island residents, replacing the wind turbines that have disappeared.

Last year, 606,000 liters of diesel were used to generate electricity on Gapa-do, or about 1,660 liters per day on average. Despite its abundant wind and sunshine, most of the electricity used by residents still comes from fossil fuels.

That does not mean Gapa-do's drive for energy self-sufficiency is over. On the contrary, the small island is once again attracting attention as a test bed for the future of South Korea's energy transition. Drawing on lessons from the previous project, the government and Korea Electric Power Corporation are pursuing a new RE100 village project that combines wind and solar power with ESS. After an earlier attempt encountered challenges, Gapa-do is once again moving toward becoming a "carbon-free island."

An Island Without Wind Turbines...Still Powered by Diesel

Hwang Jeyoung, head of the KEPCO MCS branch office, whom we met at Gapa-do Power Plant, has worked here for more than a year and is responsible for the island's electricity supply. He is a veteran who has spent more than 25 years working on islands, including at power plants on Marado, Biyangdo and Chujado in the Jeju region.

Explaining why the wind turbines were removed, Hwang emphasized the challenges of the island's unique environment. "The wind turbines and the integrated system, including the power conversion equipment, developed problems, and it became impossible to keep them operating," he said. "Because the equipment is by the sea, salt exposure takes a heavy toll, and some electrical equipment was also exposed to the elements, which created problems."

Power generation equipment is more difficult to maintain on an island than on the mainland. It is exposed to strong winds and salt, and when bad weather disrupts ferry services, bringing in outside personnel and equipment is difficult. That is why having a system that can operate reliably for a long time without breakdowns is just as important as installing the generation equipment.

Gapa-do Power Plant currently has three 150-kW diesel generators, for a total installed capacity of 450 kW. Installed in 1992, the generators were transferred from the local government to Korea Electric Power Corporation in 2003. KEPCO MCS has operated them since August 2024. Eight on-site employees handle generator operation and maintenance, as well as the management of power distribution equipment.

According to Korea Electric Power Corporation, Gapa-do Power Plant generated 1,991 MWh and transmitted 1,695 MWh of electricity last year. Average demand was 227 kW, while peak demand surged to 434 kW on August 1. By contrast, demand fell to a low of 58 kW on November 2. The difference between the highest and lowest levels of electricity use was more than sevenfold.

Gapa-do is an isolated power system with no connection to the mainland grid. On the mainland, multiple power plants are connected through the transmission network and can exchange electricity. Gapa-do, however, must meet its electricity demand using only its own generation equipment. Even if it does not generate enough power, it cannot draw electricity from other regions.

Solar power equipment remains in various parts of the island, but it is difficult to accurately measure how much electricity it generates. Solar panels were installed at some homes and at the desalination plant through the earlier project, but their operating conditions vary. "Some solar installations are still working well, while others have broken down," Hwang said. "We can't determine the exact amount of electricity they all generate, but we can see the output of the diesel generators drop noticeably when the sun gets stronger."

The earlier project did not leave the island with nothing. Some residents who installed rooftop solar panels have benefited from lower electricity bills, and the underground power distribution network built across the island is still in use. However, the lack of a sufficiently robust system for the long-term maintenance and operation of the generation equipment remains a challenge.

"With the previous project, it was unclear which agency was responsible for repairs when equipment broke down," Hwang said. "I understand that the maintenance budget was also insufficient." He added, "I understand that this time the project is being prepared with long-term maintenance in mind, so I think it will be different."

The shortcomings of the previous project have also affected residents' trust. For residents who have already experienced an energy self-sufficiency project, the more important question may be not whether new generation equipment will be installed, but how long it can operate reliably.

One resident said: "When the first wind turbines were installed, people were excited because we were told wind would generate electricity for the whole island. But within just a few years, there were more and more days when the turbines didn't work properly, and eventually they were removed. It's disappointing that the wind is still blowing so strongly, yet we're still generating electricity with diesel. This time, I hope they don't just install new turbines, but also establish a system to repair them quickly if they break down."

Weeds are overgrown at the site of a former wind turbine on Gapado, Jeju, on the 30th of last month. The only thing left where the turbine once operated is an electrical equipment box marked “Wind Power,” a reminder of a past experiment in energy self-sufficiency. Gapado is moving ahead with plans to build new renewable energy facilities after removing the old turbine. Photo by Kang Nahum

Wind, Solar and ESS...A Different Second Experiment

The government's Gapa-do RE100 village project has been designed based on lessons from the previous effort. Rather than simply increasing renewable energy generation capacity, the goal is to establish a new power supply system that integrates electricity generation, storage and consumption.

The project will run from 2026 to 2027. Korea Electric Power Corporation will build the power supply facilities; the Korea Energy Agency will install solar panels and heat pumps at public facilities; and KEPCO KDN will build an integrated control system and a platform to make operational data public.

The key equipment will include 600 kW of wind power, 990 kW of solar power and an ESS with a storage capacity of 7 MWh. The wind capacity will come from three 200-kW turbines. The solar panels will combine south-facing tilted panels with east-west-facing and vertical panels.

In particular, the project will make active use of generation equipment and storage systems produced by domestic companies. The aim is to address problems with the supply of parts and maintenance of foreign-made equipment that emerged in the previous project, while strengthening the technological competitiveness of South Korea's renewable energy industry.

One technology to watch is "grid-forming," which will be applied to the ESS. Grid-forming technology creates voltage and frequency independently, without relying on an external power grid. Whereas conventional solar and ESS systems operate in line with the voltage and frequency of the grid, grid-forming technology can also help maintain the stability of an isolated power grid.

This is particularly important on islands like Gapa-do that are not connected to an external grid. Solar panels cannot generate electricity at night, and wind power output falls when the wind weakens. To replace diesel generators, the island must be able to maintain a stable electricity supply even as renewable energy output fluctuates.

The new ESS will use vanadium flow batteries. This technology stores electricity in an electrolyte and is well suited to long-duration charging and discharging. Korea Electric Power Corporation plans to combine it with grid-forming technology to store electricity when renewable energy output is high and supply stored electricity when output is low.

However, even with sufficient renewable energy facilities in place, it remains to be seen whether diesel generation can be completely replaced at all times. If there is no wind or cloudy weather persists for an extended period, the electricity stored in the ESS may not be enough to meet the island's entire demand.

"Ideally, electricity would be supplied entirely by renewable energy 365 days a year," Hwang said. "But if there is no wind and not enough sunshine for several days, the ESS may have capacity limits."

He added, "If the new equipment operates properly, I expect renewable energy could account for more than 80% of the electricity supply. Diesel generators would serve as a backup, used when there is a power shortage or an emergency."

The way electricity is used will change, too. The Korea Energy Agency plans to install heat pumps with a combined capacity of 76 kW and solar power equipment with a capacity of 52.25 kW at three public facilities: the senior citizens' center, the village hall and the community safety center.

Heat pumps transfer heat from outside and use it for heating and cooling. Shifting from heating systems centered on fossil fuels to electricity, and using electricity as heat when renewable energy generation is high, can improve energy efficiency.

KEPCO KDN will establish an energy management system (EMS) to oversee power generation and consumption. It also plans to optimize the power supply by analyzing the operation of wind, solar and ESS systems together, and to create an open-data platform that makes information such as generation and consumption figures public.

The project budget initially proposed by the government was KRW 22 billion, but the budget finalized this year was reduced to KRW 8 billion. A budget of KRW 5.77 billion has been provisionally proposed for next year. Korea Electric Power Corporation finalized the basic plan for building the power supply facilities in August this year and is moving the project forward, including by proceeding with the procurement of solar panels and ESS equipment.

Bird's-eye view of a hybrid installation of east-west-facing vertical solar panels at the Gapado wind farm site. Korea Electric Power Corporation.

Turning the Legacy of Failure into a New Asset

The infrastructure built during the previous project also played a role in Gapa-do being selected again as a site for an energy self-sufficiency experiment. The underground power distribution network, transformers, switches and other power equipment installed during the first experiment can be used in the new project.

"Gapa-do already has basic infrastructure in place from the previous project, including power lines, transformers and switches," Hwang said. "In other regions, you would have to install this equipment before starting a new project. Here, the advantage is that new generation equipment can be connected to the existing power grid and put to use."

This is why Gapa-do is valuable as a test bed for validating new technologies after overcoming the challenges of its earlier attempt. If the island can secure a stable operating model by using the existing grid and combining it with domestically produced wind and solar equipment, ESS and integrated control technology, it could lay the groundwork for expansion to other island regions.

The government's plan is to expand the technologies and operational experience gained on Gapa-do across Jeju and use them to help domestic companies enter overseas markets. The renewable energy generation equipment, ESS and power grid control system could be packaged together and deployed in areas that need an off-grid power system.

Gapa-do's experiment is also connected to South Korea's energy transition as a whole. South Korea operates an isolated power system that is not connected to the grids of other countries. As the share of renewable energy increases, technologies to manage fluctuations in generation and maintain grid stability will become increasingly important.

If an operating model combining grid-forming, ESS and electricity demand management is validated on Gapa-do, it could help build experience needed to establish a renewable energy-centered power grid. An experiment that began on a small island could provide a technological foundation for the future of the national power grid.

Residents' daily lives are also expected to change. A higher share of renewable energy could reduce diesel consumption and carbon emissions, while making heating and cooling at public facilities more efficient. More reliable generation equipment is also expected to improve confidence in the electricity supply.

Residents are also looking forward to a future landscape in which the new wind turbines blend in with Gapa-do's green barley fields. Another resident we met on the island said, "If wind turbines of a scale suited to Gapa-do are installed, I think they could also be used as part of the tourism infrastructure in connection with the green barley festival."

After once grinding to a halt, Gapa-do's experiment in energy self-sufficiency is back at the starting line, supported by new technology and experience. Attention is now focused on whether the dream of generating the island's electricity from wind and sunshine can this time take root reliably in residents' daily lives.

This content was produced with the assistance of AI translation services.