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.

How does independent PV + storage increase value?

Increases value by about 1% relative to independent PV + storage. In other periods (July 1 shown here), storage plant cannot be fully utilized because of the operation of the PV system. Combined output of independent PV + storage plant (left figure) is as high as 70 MW, which is possible because of the separate inverters.

What is a battery energy storage project?

A battery energy storage project is a system that serves a variety of purposes for utilities and other consumers of electricity, including backup power, frequency regulation, and balancing electricity supply with demand.

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.

What is the 'value stack' in energy storage?

Owners of batteries, including storage facilities that are co-located with solar or wind projects, derive revenue under multiple contracts and generate multiple layers of revenue or 'value stack.' Developers then seek financing based on anticipated cash flows from all or a portion of the components of this value stack.

Can energy storage projects sell ancillary services?

In many regions, energy storage projects may be able to sell “ancillary services” in addition to energy or capacity either to transmission owners or to regional grid operators. For example, Swinerton’s Mira Loma, California, energy storage project.