Dive Brief:

• Xcel Energy is partnering with Sunverge Energy and Northern Reliability to test the use of battery storage with rooftop solar installations.

• The two-year pilot project is designed to demonstrate how battery storage can help integrate higher concentrations of solar power on Xcel’s grid, as well as manage voltage regulation and peak demand.

• The project involves six residential, behind-the-meter batteries and six utility-scale batteries that will be placed on utility feeder lines.

Dive Insight:

Xcel has long been a big purchaser of wind power, and has a growing amount of solar power. The company is now looking for ways to better integrate those renewable resources into its grid.

In the partnership with Sunverge and Northern Reliability, Xcel will pair battery storage with rooftop solar on houses in Stapleton's North Central Park and Eastbridge neighborhoods, areas that have among the highest concentrations of rooftop solar installations in the Denver area.

The two year pilot program will place six, 15.5-kWh Sunverge batteries in houses with rooftop solar panels by this spring.

The pilot also calls for six utility-scale batteries manufactured by Northern Reliability of Waitsfield, Vt., to be placed on either end of the distribution feed half loop and are paired to match the entire loop's reverse power flow.

The Northern Reliability batteries are expected to be installed this fall and will comprised of two 18-kW batteries, two 36-kW batteries and two 54-kW batteries. Battery duration details were not released.

The batteries will store excess solar power during the day and discharge stored power during peak usage times. Xcel says it wants to see how much solar power its grid can accommodate.

The Stapleton project is estimated to cost $4 million. It is one of two Innovative Clean Technology programs approved by the Colorado Public Utilities Commission in 2016.

"Sunverge's cloud-based platform will allow Xcel Energy to control individual Sunverge storage systems and aggregate them into virtual power plants," Ken Munson, Sunverge CEO, said in a statement. "This modest investment in storage can translate into less need for expensive feeder upgrades, as well as reduce the need to build new generation or switch on peaker plants.”

Correction: An earlier version of this post misstated a company name in the headline. Xcel's partnership is with Sunverge Energy, not Sunrun.