The Stapleton neighborhood in Denver has the largest concentration of rooftop solar in the city. That’s why Xcel Energy is using its North Central Park and Eastbridge neighborhoods for a $4 million, two-year pilot program that will test the value of storing solar energy in banks of batteries, according to a February 15 report by the ABC-TV news affiliate, The Denver Channel.
Right now, the local news outlet said, Xcel is installing six huge storage batteries across Stapleton to figure out how they can take energy from those solar panels on sunny days and save it for peak demand times.
In addition, Xcel will test the use of batteries and the operation of microgrids power systems at the new Panasonic Enterprise Solutions complex near Denver International Airport.
The two projects were approved on February 14 by the Colorado Public Utilities Commission as part of the Innovation Clean Technology (ICT) demonstration project program (Proceeding 15A-0847E), originally requested by Xcel in October 2015.
Xcel Energy is partnering with battery vendors Sunverge Energy and Northern Reliability for the test in town. The company wants not only to learn how to accommodate more solar energy onto its grid, but also manage other grid issues such as voltage regulation and peak demand.
“For the program, Xcel Energy is testing six in-home, behind-the-meter battery units and six larger, utility-scale units along the feeder that serves the majority of the North Central Park and Eastbridge neighborhoods,” said Beth Chacon, Xcel Energy’s director of Grid Storage and Emerging Technologies.
Distribution feeders bring electricity into homes and businesses and carry the energy produced by in-home solar systems to the electric grid.
All three companies want to understand how energy storage can help manage the impact of high concentration of rooftop solar energy on a feeder in these Stapleton neighborhoods. This includes accommodating more solar energy on Xcel Energy’s grid, while also storing excess solar power during the day and discharging stored power during peak energy usage times. There is also the hope of learning more about regulating voltage spikes and reducing energy costs.
San Francisco-based Sunverge Energy is providing the six in-home batteries and control software. Each 15.5-kWh, AC-coupled Sunverge One energy storage system is expected to be installed soon, and will be paired with pre-existing rooftop solar PV arrays.
Meanwhile, Waitsfield, VT-based Northern Reliability is supplying the six, utility-scale batteries that will be placed on either end of the distribution feed half loop and are paired to match the entire loop’s reverse power flow. NRI’s batteries are expected to be installed in the fall and to comprise two 18-kW batteries, two 36 kW batteries and two 54 kW batteries.
If its plan works, Xcel will keep the energy in Stapleton and will spend less money pumping electricity across power lines into the neighborhood.