Embedding renewable energy pricing policies in day-ahead electricity market clearing

• RES uplift charges are integrated in the market clearing.
• The demand clearing price entails the total cost for participating in the market.
• RES uplift charges are endogenously defined.
• A non-confiscatory market is ensured for both consumers and RES producers.
• Two implementations are studied, a feed-in tariff and a Green Certificates policy.

Since the 90s various policies have been applied for supporting the development of Renewable Energy Sources (RES), including quota or amount-based systems and price-based systems (feed-in tariffs or “FiT”). In both cases, there is a political stress when there is a need to increase the renewable uplift charge rates (out-of-market mechanism), in order to finance the RES projects. This issue is resolved by adopting a novel market framework, in which the demand entities’ clearing price entails the whole cost they are willing to pay for their participation in the energy market, including energy prices, reserve prices and the RES uplift price. A Mixed Complementarity Problem is utilized for clearing the market, in which the demand clearing prices are implicitly defined by mixing the explicit prices for energy, reserves and the RES uplift. The model retains the consistency of the supply (energy and reserves) and demand cleared quantities with the respective bids and the clearing prices, and attains a significant decrease of the payments through the relevant uplift accounts. The efficiency of the proposed model is demonstrated on a 24-h day-ahead market simulation using the IEEE RTS-96, defining endogenously the RES uplift under a system-wide FiT and a Green Certificate mechanism.