By John Fernandez
The Public Utilities Commission has given approval to Xcel Energy to undertake a solar power storage program at two locations: Stapleton and at the Panasonic campus proposed near the 61st and Pena station on the A Line. The overall purpose of the planned two-year program is to test the capabilities of current battery technologies and the integration of utility-scale battery systems with the power grid.

In Stapleton, six batteries will be installed on homes that already use solar power. Another six batteries will be installed along the utility feeder line itself. According to Andre Gouin, Xcel Energy business technology consultant, this “combination of customer-sited and utility-sited battery systems will allow us to determine whether one type of configuration offers advantages over the other.”

The PUC approval authorizes Xcel to invest $9.1 million on the program. Roughly two-thirds of the investment will be spent on the Panasonic project, which includes a 1.3 megawatt solar installation, a large, two megawatt-hour battery storage system, a microgrid “islanding” switch, and the integration and controls equipment necessary to operate them. The remaining third spent at Stapleton will be for the six utility-sited battery systems, six customer-sited systems, and the associated integration and controls equipment.

The solar storage program is being conducted as part of Xcel’s Innovation Clean Technology program used by Xcel to “demonstrate new technologies that could enable the increased adoption or integration of clean technologies into the electric system.”

According to Gouin, Stapleton was selected because this “neighborhood has one of the highest penetrations of solar within Xcel Energy’s Public Service Co. of Colorado service territory.” A process for selecting participating homeowners has yet to be determined but geographical distribution may be one criterion. Selection and installation are expected in the first quarter of 2017. The PUC approval requires Xcel to provide milestone reports about project costs so they can be vetted for future rate proceedings. All data would be made available to the public.

Rebecca Cantwell, executive director of the Colorado Solar Energy Industries Association (COSEIA), applauded Xcel for undertaking the pilot study, saying that everyone benefits from a grid less vulnerable to outages. She said, “Battery storage may be the ‘next big thing,’ a technology which is in its infancy in Colorado.” Assuming a successful test, she said policy changes can’t be predicted but the prospect of more distributed energy production and storage will inevitably raise important issues that will need to be addressed by the state’s Public Utilities Commission. Cantwell said, “We think it is very important that what is learned from the test be shared with all interested parties, including companies that wish to get involved in battery storage in the future. We will be working to ensure an open marketplace for this important new technology.”