자원·환경경제연구 ISSN:1229-9146(Print) Environmental and Resource Economics Review

This study quantifies how the design of two-way Contracts for Difference (CfDs) affects generator revenue stability and market efficiency. Using observed system marginal prices from the Jeju power market (2019–2025; 61,368 hours) combined with 1MW representative solar and wind generators with nationwide average generation profiles, we simulate settlement outcomes across combinations of reference-price averaging periods, weighting schemes, and negative-price non-payment rules. Four findings emerge. First, the reference period determines not the level of revenue stability but the cycle of cash flows being stabilized: under technology-weighted reference prices, hourly, daily, and monthly references yield virtually identical unit revenues and monthly volatility, while only the annual reference raises monthly volatility. Second, solar generation during negative-price hours is self-restrained under monthly or longer references even without a rule, whereas wind is restrained only when a non-payment rule applies, provided that its strike price exceeds the threshold at which the net unit revenue turns negative. Third, system-weighted reference prices curb settlement inflation associated with self-cannibalization but transfer basis risk to generators, substituting for longer reference periods. Fourth, daily or longer references provide a premium for west-facing installations, though insufficient to offset the associated generation loss. These results suggest that a technology-weighted reference price with a daily or longer averaging period, combined with a non-payment rule, constitutes a design that jointly achieves revenue stability and market efficiency.