South Korea RPS Phase Out 2026 — Solar EPC Playbook

What the RPS Was and Why It Mattered

South Korea's Renewable Portfolio Standard, introduced in 2012, required power generation companies with installed capacity above 500 MW to source a rising percentage of their electricity from renewable sources. The mechanism worked through Renewable Energy Certificates. Solar generators earned K RECs for each unit fed into the grid. Obligated power companies bought enough K RECs to prove compliance with their annual quota. This created a trading market and a separate revenue stream beyond electricity sales that made project economics viable, particularly for smaller and medium-scale solar plants.

The system had structural problems. IEEFA described it plainly: compliance relied primarily on renewable energy certificates that became expensive due to limited supply and did little to drive capacity expansion. Implementation lagged. A 2023 government revision reduced RPS targets from 25 percent for 2026 to 15 percent, precisely because the quota system was not driving enough actual generation. The signal was clear: the RPS was not delivering what energy policy needed.

The announcement that the RPS will be fully phased out by end of 2026 and replaced by a contract auction system is not a surprise to those who have been watching Korean energy policy. It is, however, a definitive end point that requires every solar EPC with projects depending on K REC income to act now.

What Replaces the RPS

The replacement is a competitive auction and long-term contract system. The government sets total capacity to be procured by energy source. Developers bid on price. Lowest bids win a long-term contract, effectively a Power Purchase Agreement, at a fixed price for a defined period. This removes the complexity of managing dual revenue streams (electricity and K RECs) but also eliminates the K REC spot market as an upside mechanism.

For solar EPCs, the change means that any project financial model including K REC revenue beyond 2029 needs revision. Projects that have not reached financial close must account for the post-RPS environment. The auction market also rewards cost efficiency. EPCs who can reduce project costs through better design, procurement, and construction productivity will win auction-based contracts. Those with a cost structure unchanged from the pre-2026 environment will be outbid.

Rooftop solar is being treated separately. The Korean government is actively supporting expanded rooftop installations, increasing the subsidy ceiling from 100 kW to 200 kW in 2025 and promoting RE100 industrial complexes. The auction system primarily targets utility scale. EPCs focused on rooftop work are less directly affected by the RPS phase out than those doing utility scale projects, but need to understand the market context for their clients' conversations.

The K REC Transition Period: What It Means for Existing Projects

Existing projects registered in the K REC system will continue earning certificates through a transition period until approximately 2029. The IEA PVPS Korea report confirms the K REC spot market will be gradually phased out during this window. This transition timeline is the expected framework based on the IEA PVPS analysis and will be finalised in Korea's forthcoming 12th Basic Plan for Long-term Electricity Supply and Demand.

The 12th Basic Plan is the definitive document to watch. When it is published, it will specify the exact transition terms for existing K REC projects, including the timeline, any grandfathering provisions, and the mechanism for moving existing projects into the new system. Every EPC with existing K REC projects should review the 12th Basic Plan immediately upon publication and update their project financial models accordingly.

In the meantime, the practical action is to model your project economics under two scenarios: one that includes K REC revenue through 2029 on the expected transition basis, and one that calculates project returns without K REC income from 2027 onward. If the project only works financially with K REC income, that is the risk that requires management before financial close.

What the Auction System Means for Your Business Model

The transition to a competitive auction system fundamentally changes what it takes to win work in the Korean solar market for utility-scale projects. Under the RPS, project economics were supported by K REC prices alongside electricity revenue. Under the auction system, the only support mechanism is the contract price per kWh. The project that delivers the lowest levelised cost of electricity wins the contract. Cost efficiency at every stage of project development and delivery becomes the primary competitive lever.

For EPCs building their business around the new market, this means investing in the capabilities that reduce per-kWh project cost: efficient site selection that maximises irradiance, technical design that minimises balance-of-system cost, procurement processes that capture equipment cost savings, and construction productivity that reduces labour cost per MW. These capabilities differentiated the best EPCs under the RPS system. Under the auction system, they become the entry requirement.

The K REC spot market, even in its final 18 months, is in structural decline. Obligated power companies are reducing forward purchases knowing the obligation ends in 2026. Generators who are banking K RECs hoping for a price recovery are taking a position in a market designed to wind down, not recover.

Corporate PPA as an Alternative for Projects Outside the Auction

For EPCs working on projects that may not compete effectively in the government auction, the corporate Power Purchase Agreement market in Korea is growing. Major Korean manufacturers in electronics, semiconductors, and automotive have RE100 commitments and are actively seeking long-term renewable offtake agreements. Projects with favourable siting, grid access, and proximity to large industrial demand centres may be viable on a PPA basis even without winning a government auction contract.

The PPA market cannot fully replace government auction volumes in the near term, and PPA negotiations are time-intensive and require creditworthy offtakers. However, for EPCs with the right client relationships and project locations, the corporate PPA pipeline is a real alternative to the government auction for projects that cannot compete on price alone.

Frequently Asked Questions

Q1. Will existing solar projects stop earning K RECs when the RPS ends?

No, not immediately. Existing projects registered in the K REC system will continue earning certificates through a transition period until approximately 2029. The IEA PVPS Korea report confirms the K REC spot market will be gradually phased out during this window. The exact transition terms will be specified in the government's 12th Basic Plan for Long-term Electricity Supply and Demand, expected to be published in 2026. Watch for this document: it is the definitive guide to how existing projects will be treated, including any grandfathering provisions and the mechanism for transitioning existing projects into the new system.

Q2. How does the new auction contract differ from the old RPS revenue model?

Under the old RPS model, a generator had two separate revenue streams: electricity sold to the grid at market rates, and K RECs sold separately through the certificate market. Managing both required tracking electricity generation, REC issuance, REC pricing, and REC sales independently. Under the new auction system, the generator bids a single price per kWh and receives a long-term contract at that price for a defined period. One revenue stream, one counterparty, one contract. The simplification reduces administrative complexity but removes the potential upside of a strong K REC market price. Predictable revenue is the trade-off for eliminating certificate market exposure and complexity.

Q3. Can an EPC still build utility scale solar in South Korea after 2026 without winning an auction?

Yes, but without government revenue support. A project that does not win a contract auction must sell electricity as a merchant generator at wholesale market prices, or enter a direct corporate PPA with an industrial buyer. Corporate PPA demand in Korea is growing: major electronics, semiconductor, and automotive manufacturers with RE100 commitments are actively seeking long-term renewable offtake agreements. Projects with favourable siting, grid connection, and proximity to large industrial demand centres may be viable on a PPA basis. However, without a government contract, the project's revenue is exposed to wholesale market price fluctuations, and financing at competitive rates requires a creditworthy offtaker agreement to provide the cash flow certainty lenders need.

Q4. How does the RPS phase out affect financial modelling for Korean solar projects?

Any project model that includes K REC revenue as a standalone income stream beyond 2029 needs revision now. The practical changes: remove K REC income as a separate revenue line from 2030 onward; instead model project revenue as a single blended electricity price reflecting either the auction contract price (if the project wins one) or a merchant/PPA electricity price. For projects targeting the auction system, model sensitivity scenarios around different auction clearing prices rather than a single assumed K REC price. The auction ceiling price and competitive dynamics will determine clearing prices, so optimising project cost structure is the primary lever, not revenue assumption management.

Q5. How has the RPS phase out already affected K REC spot market prices?

K REC prices have been under downward pressure precisely because obligated power companies are reducing forward procurement ahead of the system's closure. Buyers who previously purchased K RECs to meet annual quotas are reducing positions knowing the obligation ends in 2026. This has contributed to the compliance failures that IEEFA documented: many obligated utilities have been undercomplying rather than paying the penalty premium, calculating that the penalty cost is lower than the K REC market price. For generators currently selling into the K REC spot market, expect continued price softness through 2026. Holding K RECs in anticipation of a price recovery is a poor risk position in a market designed to wind down.

Q6. What type of projects are most likely to win the new contract auction?

The auction is competitive on price: lower bids per kWh are more likely to win. Projects with the lowest levelised cost of electricity will have the strongest auction position. The key LCOE drivers for Korean projects: access to high irradiance sites in southern coastal regions and Jeolla Province, low land cost or existing land rights, proximity to grid connection points that reduce transmission infrastructure cost, and project scale sufficient to amortise development and financing costs. Projects in the 5 to 20 MW range with favourable grid access and lower construction costs will be the most competitive bidders. EPCs who can design and build at lower cost per watt give their developer clients a structural advantage in the auction process.

Sources

• IEA PVPS Korea , iea-pvps.org , Korea solar 2025, RPS phase out end 2026, contract auction replacement, K REC transition
• IEEFA , ieefa.org , South Korea renewable energy pivot, RPS compliance failures, March 2026
• CMS Law Korea , cms.law , South Korea renewable energy legal guide, K RE100, RPS, MOTIE framework