There are pros and cons to each type of energy storage. Utility-scale battery storage is still an emerging technology, whereas pumped hydro storage is proven to work. Battery storage can ramp up to full power within seconds, but can supply that power for less time, when compared to pumped storage. Typically for grid applications, energy batteries are sized up to four hours. Pumped storage, for example, can provide more energy over a longer period of time. As to cost and construction, pumped hydro is very capital intensive and takes significantly longer to build.

The batteries being installed in Hanover County will be two 40-foot containers (similar in size to shipping containers), while New Kent will have several refrigerator-sized modules on a single concrete pad.

The batteries in this pilot can store 56 MWh of energy.

The batteries in this pilot project can deliver a total of 16 MW of power to help keep the grid stable and reliable for our customers.

The safety of our employees and customers is our top priority. As with any lithium-ion battery, you are dealing with large amounts of stored energy in a small place, and fire is a danger associated with them. We have taken precautions with regards to the batteries’ physical placement to minimize hazards to our customers, their property and our employees. The industry continues to study this technology to improve the batteries’ safety characteristics.

These projects will allow us to analyze the use of energy storage for grid stability support as an alternative to traditional grid upgrades. These pilot projects will enable Dominion Energy to better understand how best to deploy and operate batteries to help overcome the inherent fluctuation on wind and solar generation sources.

The three proposed Central Virginia-based lithium-ion projects will cost approximately $33 million to construct. Pending SCC approval, the experimental pilots would last five years once operational in December 2020.

The company is committed to providing our customers with a reliable, affordable and diverse supply of energy. The Grid Transformation & Security Act of 2018 enabled 30MW of battery storage generation to be developed as a pilot project. If approved by the SCC, the pilot will allow us to study this emerging technology and understand how it fits into Virginia’s energy future. As the company continues to forge ahead as an industry leader in renewable energy, various storage technology will be needed to ensure a balanced and reliable energy grid.

Not at this time. Different kinds of generation are utilized depending on the magnitude of the demand.