Dive Brief:

• Virginia regulators have approved Dominion Energy's proposal to construct its first battery storage installations, according to a Feb. 25 statement from the company.
• At a combined 56 MWh, the projects will be the largest examples of utility-scale battery storage in the state, where Gov. Ralph Northam, D, and lawmakers are calling for Dominion to add over 2 GW of storage by 2035 as part of the effort to achieve a statewide goal of net-zero emissions by 2050.
• Dominion plans to use the projects as testing grounds for how to use lithium-ion batteries to integrate more solar power onto the grid efficiently and potentially reduce the need for distribution grid upgrades by using the batteries as non-wires alternatives.

Dive Insight:

In a Feb. 14 order, the Virginia State Corporation Commission ruled that the combined over-$33 million in expected costs for the projects are reasonable and prudent. At $26.1 million, most of those costs will go to two of the projects — a 2 MW, direct current battery system with a duration of four hours that will be coupled with a 10 MW, 40 MWh alternating current system.

The two systems will be installed at Dominion’s Scott Solar facility to “provide valuable information on the proficiency of battery technology to store energy generated from solar panels during periods of high production and release energy during periods when load is high or solar generation is low,” as well as “reveal how well a battery can optimize power production of the solar facility,” Dominion’s statement said.

The next biggest project is a $4.1 million, 2 MW, 4 MWh battery system that Dominion plans to install at a specific substation to study how to reduce transformer load, a goal that could show the path forward for the utility to use storage as a “non-wires alternative” to capital investments into distribution grid upgrades. Finally, a $2.9 million, 2 MW, 4 MWh battery system will be used to study how to prevent solar energy from backfeeding onto the transmission grid.

The Virginia House and Senate recently passed versions of the Clean Economy Act, each of which include a requirement that Dominion acquire 2,700 MW of energy storage capacity by 2035.

Because the House and Senate versions of the legislation have yet to be reconciled into one final bill, it is not clear if the pilot projects will count toward that storage requirement, according to Dominion spokesman Rayhan Daudani. But the utility plans to use the pilots to “get a better sense of how we can deploy storage at a larger scale,” he said.

In comments on the proposed pilot programs, environmental organization Appalachian Voices said the commission should approve the projects, but said that Dominion should do more with the batteries than it has proposed. Dominion “has structured the Pilot Program in a manner that hardly utilizes the assets and leaves them sitting idle the majority of the time,” the group said, calling for the utility to also test the batteries’ abilities to provide additional uses like ancillary services, frequency regulation and peak shaving.

Dominion responded that while it does plan to test the batteries for more than the primary goals of the program, “the Company would not want to jeopardize the information and experience gained from the primary use case by adding secondary and tertiary use cases too quickly,” which could degrade the batteries.

Ultimately, Dominion agreed to include studies of these additional uses in annual reports to be filed over the course of the five-year pilots. Among the metrics to be included in annual reports is the reduction in Dominion’s capacity obligations for the PJM market provided by the new battery systems installed there, such as the Scott solar facility -- a behind-the-meter resource connected at the distribution level.