Facing a sustained increase in the demand for electricity, many countries are concerned about how to add new capacity that is sufficient, reliable, secure, and least-cost. Focusing on World Bank client countries, this report assesses the potential of electricity contract auctions for adding new and retaining existing generation capacity. The report examines five main types of electricity auctions and presents the major issues and characteristics of each. It includes a section dedicated to renewable energy auctions. Case studies of the auction mechanisms in several countries are presented.