Speed or Efficiency? Korea’s Renewable Push Needs Grid, Finance, and Subsidy Reform Together

Korea needs to add renewable capacity four times faster than before, yet grid congestion is already forcing generators to cut output. Reaching 100 GW by 2030 means adding at least 6.8 GW every half-year, against a 1.7 GW average over the past 5.5 years. Meanwhile, spending under the main subsidy scheme, collected through electricity bills, reached 4.5 trillion won in 2025 alone. The authors combine a cost-benefit analysis with cross-country panel data to test whether speed and efficiency can go together.

The Subsidy Clears the Cost-Benefit Test Only Narrowly

Under conservative 2020 estimates, each won of subsidy generates 1.33 won in social benefit for solar PV and 1.18 won for onshore wind. Learning-by-doing, the know-how that lowers the cost of later installations, supplies roughly one-third of estimated benefits; without it, the figures fall to 0.89 won and 0.80 won. These values are not fixed: long-term revenue certainty and investment that responds to price signals can set off a virtuous cycle that lifts them.

High Costs Do Not Fully Explain the Slow Rollout

Korea’s generation costs are relatively high among major economies, yet its renewable generation share remains below the level of countries with comparable costs. Cross-country panel analysis links better financing conditions (and, for solar PV, better grid conditions) to higher shares even among countries with similar costs, pointing to structural barriers beyond generation costs.

Two Bottlenecks Undermine Subsidy Efficiency

Between 2003 and 2023, generation capacity grew by 154% while the transmission network expanded by only 26%. On financing, producer revenues swing with volatile wholesale electricity and certificate prices. Stable long-term channels are thin: solar PV and onshore wind auctions have been undersubscribed, and direct corporate power purchase agreements have yet to take off. Without secure long-term revenue, producers face a higher cost of capital.

Curtailment and connection delays then cut sales and make revenues harder to forecast, which lenders price into a higher risk premium. This weakens new investment and producers’ responsiveness to price signals, and with it the virtuous cycle behind the subsidy’s payoff.

Three Pillars Must Advance in Unison

The authors identify grid infrastructure as the most urgent pillar, since a bottleneck there leaves financing and deployment support ineffective. That means clearing obstacles to transmission expansion and building a market that compensates energy storage and demand response. With legal frameworks now taking shape, the test is effective implementation.

On financing, they call for effective long-term auction contracts and policy finance that crowds in private capital. On subsidies, contracts for difference, now under consideration to stabilize producer revenues, should be designed using the cost-benefit findings, with multi-year auction volumes announced in advance. Isolated reform on any single axis will not be enough.