Variable Renewable Energy Participation in U.S. Ancillary Services Markets: Economic Evaluation and Key Issues

This research estimates the economic value of standalone and hybrid (battery-paired) variable renewable energy (VRE) participation in ancillary services (AS) markets, from resource owner and electricity system perspectives, in each of the seven U.S. independent system operator and regional transmission organization (ISO/RTO) markets. Across ISO/RTO markets, average (2015-2019) simulated incremental revenues from regulation market participation were 0.0-2.9/MWh (+0-15% of revenue without participation) for standalone VRE owners and 1-33/MWh (+1-69%) for hybrid VRE owners. In most markets, standalone and hybrid VRE were able to provide regulation reserves during periods with high regulation prices, suggesting that VRE participation in AS markets could have high system value. The analysis highlights the value of separate upward and downward regulation products and suggests that ISOs/RTOs might consider initially focusing on enabling hybrid VRE provision of AS