On March 16, 2020, the Department of Energy's (DOE's) Lawrence Berkeley National Laboratory published a report detailing the advantages and disadvantages of power plants that combine wind and solar projects with on-site batteries (hybrid power plants) within the bulk power system.

Variable renewable energy (VRE) technologies, such as wind and solar photovoltaics (PV), have increasingly penetrated the US energy market in recent years, reaching approximately nine percent penetration in 2018. Competitive costs and continued policy support suggest that further penetration of VRE technology will continue, increasing the need for grid flexibility. As battery prices have declined, there has also been an increased interest in integrating them onto US grids by co-locating them with generation facilities at the point of interconnection.

Currently there is a 4,600-megawatt (MW) hybrid capacity, 14,700 MW in the immediate development pipeline, and 69,000 MW in longer-term interconnection queues.

Advantages of hybrid power plants include:

Hybrid power plants do have certain disadvantages, including:

Additionally, there still exists some regulatory uncertainty surrounding hybrids, namely in the way of ever-evolving market rules and the future availability of financial incentives.

The report further analyzes that, based on recent power purchase agreement (PPA) prices for solar and battery hybrids, additional revenues can exceed additional costs when a four-hour battery is added to a standalone solar facility.

The report also concludes, however, that more research is needed to clarify the long-term cost-reduction potential, market value, and risks and benefits of hybrid power projects within the electricity system.

For more information on renewable energy, see Practice Note, Renewable Energy: Overview.