Can a utility-scale PV plus storage system provide reliable capacity?

Declining photovoltaic (PV) and energy storage costs could enable “PV plus storage” systems to provide dispatchable energy and reliable capacity. This study explores the technical and economic performance of utility-scale PV plus storage systems. Co-Located? AC = alternating current, DC = direct current.

What is integrated photovoltaic energy storage?

Among these alternatives, the integrated photovoltaic energy storage system, a novel energy solution combining solar energy harnessing and storage capabilities, garners significant attention compared to the traditional separated photovoltaic energy storage system.

How does a DC-coupled storage system affect PV output?

DC-coupled system (right figure)—with shared 50-MW inverter—must shift storage output to lower-price periods to accommodate PV output. DC-coupled system value decreases by about 1% relative to independent PV + storage system. Impacts of DC tightly coupled storage systems are more significant.

Why is LCOE a incomplete metric for evaluating PV plus storage?

LCOE is a incomplete metric for evaluating PV plus storage because of the significant increase in value associated with storage—benefit/cost ratio is an alternative metric that accounts for the added value. Coupling by co-locating storage and solar can decrease the overall net costs of deploying PV and storage (AC coupling).

How many mw can a PV & storage plant produce?

Combined output of independent PV + storage plant (left figure) is as high as 70 MW, which is possible because of the separate inverters. DC-coupled system (right figure)—with shared 50-MW inverter—must shift storage output to lower-price periods to accommodate PV output.

How does DC-coupling affect PV capacity value?

Result is a total capacity value of $7.5 million/year. DC-coupling causes no decline in capacity value, because the PV capacity credit (20 MW) plus the storage capacity (30 MW) equals the inverter capacity of 50 MW. Independent, AC-coupled, and DC-coupled (flexible charging) storage receives 7-year MACRS (Modified Accelerated Cost Recovery System).