[Report] Midnight Renewable Energy 'Peak Time'... How Tourist Destination Jeju Lives with Wind Power

Visiting Jeju Dongbok and Bukchon Wind Power Complexes
Peak Electricity Consumption Time
Coincides with Tourist Activity Hours
Output Control Due to Overproduction
Annual Losses of Hundreds of Millions Won Remain a Challenge

One of the 15 wind turbines at the Dongbok and Bukchon wind power development sites in Jeju is stopped. Photo by Choi Seoyoon

[Asia Economy Reporter Choi Seoyoon] A place where electricity demand surges only at night when everyone is asleep, and a certain amount of electricity can be generated by ‘wind’ to meet that demand. Last month, at the Dongbok and Bukchon Wind Power Complex in Gujwa-eup, Jeju, two giant wind turbines, each 80 meters tall, were operating. This site is operated by Jeju Energy Corporation, with an annual power generation of 66,659 MWh. The installed capacity is about 30 MW, making it the largest wind power complex among the corporation’s facilities.

Here, wind turbines alone can supply electricity to residents. They generate enough electricity to cover 18,000 households based on a family of four. Kang Sanghyun, Head of Disaster Safety Operations at Jeju Energy Corporation, explained, "It covers the urban area of Yeondong, close to Jeju Airport," adding, "It also has an annual carbon dioxide emission reduction effect of about 46,000 tons."

The operating wind speed ranges from a minimum of 3.5 m/s to a maximum of 25 m/s. Generally, a wind speed of about 6 to 7 m/s is considered economically viable. This is similar to the average annual wind speed in Jeju. The power generation rate relative to installed capacity is about 20-25%, which is higher than the typical 15% of general wind turbines. The generation capacity per turbine is 2,000 kW.

Jeju, which has excellent ‘wind resources’ with an average annual wind speed of 6 m/s, has different times for discharging electricity stored in energy storage systems (ESS) compared to the mainland. Jeju, visited by about 12 million people annually, sees tourists’ main activity times from 5 to 10 a.m. and 6 to 11 p.m., coinciding with the peak electricity consumption times in the region. This differs from the mainland’s peak electricity consumption times, which are from 9 a.m. to 12 p.m. and 1 to 5 p.m., during factory operations and office hours. Kang said, "The major electricity consumers in Jeju are accommodations and restaurants used by tourists," noting, "The number of rooms in Jeju’s luxury hotels has increased from 4,000 in 2007 to 20,000 currently."

Although there are usually difficulties in installing turbines due to residents’ acceptance issues, Jeju is different. Conflicts with fishermen over turbine noise can arise, but Jeju Energy Corporation conducts public contests in villages, negotiates, and then carries out projects. This is similar to how villages and public sectors collaborate and lead projects in the UK, Denmark, and the Netherlands.

The power conversion device (left) and on-site control system (right) installed inside the lower part of the wind turbine towers in Dongbok and Bukchon, Jeju. Photo by Choi Seoyoon

However, the issue of ‘output control,’ where turbines must be temporarily stopped due to excess power production, remains an unsolved challenge. On this day as well, at the request of the Korea Power Exchange, 13 out of 15 turbines had to be stopped despite the wind blowing. Output control reduces the complex’s power generation by about 3-5%. This results in losses of several hundred million won annually borne by the corporation.

From the Power Exchange’s perspective, it is necessary to enhance grid stability within the area. This means they cannot adjust to the fluctuating wind power generation that increases or decreases depending on the weather. Even though Jeju has well-equipped renewable energy facilities like wind power, the power grid with higher generation efficiency must be prioritized.

There are also calls for the direct power purchase agreement (PPA) system, which allows not only Korea Electric Power Corporation (KEPCO) to monopolize renewable energy sales but also enables direct transactions with necessary individuals, to be activated. The issuance of RECs (Renewable Energy Certificates) cannot be increased either. This is money accumulated by deducting 3.7% of the electricity bill consumers pay monthly for KEPCO’s project development.

Even actively utilizing the ‘Plus DR (Demand Response)’ system has its limits. Plus DR is a system that stabilizes the power grid by increasing customers’ electricity usage at specific times to balance supply and demand, providing incentives to participating customers. Jeju has been included in the list since March. Regarding the output control issue, Kang said, "Creating separate demand to respond to peak times when electricity is overproduced would be effective," adding, "A system where the state or local governments provide subsidies during output control is necessary."