US State regulators have given utility-holding company Xcel Energy permission to test the use of large lithium batteries to store solar power.
The testing will take place at two sites in the Stapleton neighbourhood in Denver, Colorado.
On one site, Xcel will install a utility-scale power system at a car park at Denver International Airport.
It will be backed up by a 1-2 MW lithium battery that can be operated as a microgrid to provide back-up power in emergencies as well as connect to the regional grid.
The second site nearby will comprise six batteries at private residences that already have rooftop solar systems.
Each project will specifically test the batteries’ ability to mitigate voltage fluctuations stemming from grid-installed solar power; reduce system peak demand and demand on the feeder; reduce energy costs; and provide back-up power to the building.
The Colorado Public Utilities Commission (PUC) will contribute $6.7 million to the cost, with the rest split between the two projects, which could go ahead this year.