Auctions are a promising tool to support worldwide renewable energy expansion. Nevertheless, their introduction poses a serious challenge to both policy makers and project developers. Our aim is to develop a bridge between auction theory and the implementation of auctions in the context of renewable energy support (RES). We present suitable theoretical concepts to model the specific situations for RES. In addition, we provide structured theory-based guidance for implementation and participation. In this regard, we theoretically analyze auction formats that are potentially suitable for renewable energy auctions. We focus on the most discussed auction formats in practice: pay-as-bid and uniform price auctions. We highlight advantages and point to potential pitfalls for bidders and auctioneers under relevant market and framework conditions in the RES context. Finally, our theory-based results are substantiated by first-hand experiences from different countries.