In recent years, there has been significant growth in the expected capacity of solar + storage hybrid systems. Nearly two-thirds of battery capacity expected to come online between 2021 and 2024 will be paired with a solar plant, and one-third of solar photovoltaic (PV) capacity in interconnection queues is proposed as a hybrid plant.
This study explores the trade-offs between hybrid solar + storage plants compared to stand-alone configurations using EPRI’s U.S. Regional Economy, Greenhouse Gas, and Energy (US-REGEN) capacity expansion model. A DC-coupled solar + storage hybrid system technology option is incorporated into the US-REGEN model for the first time, capturing cost and performance impacts of coupling solar PV and lithium ion batteries. Three scenarios with varying carbon reduction targets and cost and technology assumptions are analyzed to understand which factors influence whether hybrid plants are deployed over stand-alone configurations and how different scenarios impact the optimal design of a hybrid solar + storage plant.
The analysis finds that the potential cost savings due to the shared infrastructure of hybrid plants can make these projects economically advantageous compared with stand-alone solar PV and battery storage plants and can result in system level cost savings. It also finds that a hybrid plant can result in significant changes to the optimal design parameters of the solar field compared to stand-alone plants.