In this webinar, researchers from Lawrence Berkeley National Lab will discuss their new study on variable renewable energy (VRE) participation in U.S. ancillary services (AS) markets. Participation of VRE in AS markets is important as they could provide a new source of revenues for VRE resource owners to offset declining energy and capacity values and a new tool for power system operators to address emerging system constraints. We use historical market prices to estimate the economic value of standalone and hybrid (battery-paired) VRE participation in 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. We find that across ISO/RTO markets, participation in regulation reserve markets could increase revenue by +0-15% for standalone VRE owners and +1-69% for hybrid VRE owners. However, ISO/RTO reserve markets are relatively thin and have the potential to become saturated by energy storage projects that are currently in ISO/RTOinterconnection queues. The webinar will also highlight the high system value of new sources of ancillary services and the advatnages of separate upward and downward regulation products.