25 GW Offshore Wind Target Requires Sea Area Seven Times the Size of Seoul

Solutions for Our Climate and GESI Release Study Findings
4,300 km2 of Development Zones Needed for 24 GW in Competitive Bidding

Artist's rendering of the Shinan-Ui offshore wind farm

The government has set a target of deploying 25 gigawatts (GW) of offshore wind capacity by 2035. A new study has found that achieving this target will require sea areas equivalent to seven times the size of Seoul.

Solutions for Our Climate and the Green Energy Strategy Institute (GESI) said on October 14, in a study titled “Research on the Marine Area Required to Meet Offshore Wind Deployment Targets,” that about 3,800–6,500 km² of newly designated development zones—approximately 6.3–10.7 times the area of Seoul—would be needed to accommodate the 24 GW of capacity planned for competitive bidding in government-designated development zones by 2035. Under the baseline scenario, the required area was estimated at about 4,300 km², or approximately 7.1 times the area of Seoul.

The researchers said they analyzed the capacity and area of 34 domestic offshore wind farms and 55 major overseas farms, then estimated the marine space required while accounting for factors such as farm size and whether the facilities were fixed-bottom or floating.

Alongside its target of deploying 25 GW of offshore wind capacity by 2035, the government announced a bidding plan for a total of 55 GW between 2026 and 2035. Of this, 31 GW will be pursued through existing competitive bidding, while 24 GW will be pursued through competitive bidding for development zones, where the government designates sites in advance.

Deployment and bidding are different concepts. Deployment refers to the capacity of power facilities that will actually be installed, while bidding is the stage at which projects are selected. Since developing and building projects takes time even after bidding, holding bids for 55 GW by 2035 does not mean that all 55 GW will be operational in that year.

The approximately 4,300 km² of new development zones estimated in this study under the baseline scenario is the area needed to accommodate the 24 GW slated for competitive bidding in development zones. Given the time required for projects, this capacity is expected to come online in stages through the mid-2040s.

Development zones are areas designated in advance by the government for offshore wind projects. In terms of housing, securing development zones is like preparing land on which to build homes. Just as setting a target for the number of homes to be supplied does not mean they will be built, offshore wind development requires preparing sites that can accommodate the planned capacity of power facilities.

The researchers said they calculated the area needed for offshore wind installations based on an estimate of “installed capacity density”—the amount of power generation capacity that can be installed in 1 km² of sea—suited to conditions in South Korea.

The total marine area required to meet the 2035 deployment target of 25 GW was analyzed separately. When the total planned capacity, including existing farms and already selected projects, was converted using the same effective-density assumptions, the required area was estimated at about 3,700–6,660 km², or about 4,340 km² under the baseline scenario.

The analysis found that the 24 GW scheduled for competitive bidding in development zones by 2035 could be accommodated, in terms of total area, within the potential sites currently identified as preliminary zones. Preliminary zones are areas the government designates first to assess site suitability before formally designating development zones.

However, areas that appear suitable for installation on a map are not necessarily areas where projects can actually be developed. If suitable areas are fragmented into small sections, it may be difficult to build large-scale farms even when their combined area is sufficient. Additional restrictions related to military facilities and regional grid connection conditions could further limit the areas that can actually be used as development zones.

The study concluded that securing contiguous areas that can actually be developed at the right time is more important than the total area of the sea.

Lee Suhyeon, a researcher at Solutions for Our Climate, said, “Even if the government sets bidding volumes, bidding cannot proceed as planned unless the waters where projects will be built are ready. With the first competitive bidding for development zones scheduled for the second half of 2029, the initial development zones must effectively be designated within the next two to three years.” Lee added, “The government should establish an annual plan for designating development zones in coordination with the bidding schedule and also review grid connection conditions.”

Kim Boram, associate research fellow at the Green Energy Strategy Institute, stressed, “To meet the 2050 carbon neutrality target, we must ease spatial constraints to expand the areas suitable for fixed-bottom offshore wind development while also advancing floating offshore wind deployment and expanding offshore power grids.”

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