De-rating of wind and solar resources in capacity mechanisms: a review of international experiences

Abstract

Non-conventional renewable energy technologies are already a key element in the expansion of many power systems. These resources, whose deployment was fostered through different types of support mechanisms in the last decades, can now enter the market, in many jurisdictions, without the need of any specific economic aid, beyond the one that conventional technologies may need or may be benefitting from. Therefore, where capacity mechanisms are in place, non-conventional renewable technologies should be involved in these markets as any other technology, thus not only being able to receive a capacity remuneration, but also being subject to the commitments that a capacity contract entails. A key and challenging design element to allow this participation is the definition of a methodology to evaluate the actual (or expected) contribution to reliability from renewable technologies. This article presents a comprehensive review of international experiences on this design element, encompassing eleven power systems from the United States, Latin America, and Europe.