Reserve price: Lessons learned from Brazilian electricity procurement auctions

Auctions have been used in several formats in the electric energy industry. In general, regulators may be uncomfortable initiating a reverse auction at a higher-than-expected final price, fearing that participants may sell their energy at an excess profitability. Nevertheless, evidence from electricity procurement auctions conducted in Brazil supports the findings that these types of auctions have the opposite effect. By attracting a larger number of agents, these auctions can trigger stronger competition and lead to lower settlement pricing. Accordingly, the Brazilian cases examined in this article present significant evidence to support this directional theory. In fact, there are some cases of electricity procurement auctions that show that inadequate auction reserve pricing leads to inefficient outcomes and may also cause the auction to fail. On the other hand, auctions with adequate price caps have led to lower final clearing prices, thus contributing to reasonable final energy pricing. - Highlights: • Outcomes from Brazilian electricity procurement auctions were analyzed. • Cases of success and frustration after adopting (in)adequate reserve prices. • Setting different price caps per source is inefficient. • Higher-than-normal price cap is more effective than fine-tuning reserve prices