United Power held a ribbon-cutting ceremony in December to celebrate its newly energized battery storage facility and the cooperative’s continued commitment to adopting and implementing innovative technology.
Currently the largest utility-scale battery storage facility in Colorado, the Tesla PowerPack battery system, built in collaboration with ENGIE North America, is expected to save the cooperative roughly $1 million annually in wholesale capacity charges. Energy generated from all sources on United Power’s grid will be stored during low-demand hours to be discharged during high-peak periods throughout the year.
“As a co-op, we have an obligation to our communities and members to continue scanning the horizon and exploring innovative technologies that help distribute affordable and reliable power,” said Jerry Marizza, United Power’s New Business Director. “When we stop looking ahead, that’s when we start falling behind. We hope to continue setting the bar for other utilities to follow.”
The system has the capacity to store and distribute up to four megawatts of energy, or enough to power up to 700 homes simultaneously. Size and duration of the batteries used was determined during a study of United Power’s monthly load profile in early 2018.
“Energy storage is the next logical step to integrating more renewables into the grid,” said Marizza. “As long as people want to watch television at night, renewables can’t provide 100 percent of energy needs without storage.”
Over the past few years, United Power has added other innovative and renewable projects to benefit its members. From Colorado’s first community solar farm to methane gas collection at the Erie landfills, these projects make economic sense for our members while providing reliable power.


You can fill the same 5-gallon bucket with either a garden hose, or a fire hose. A garden hose will not fill as quickly – but the hose costs less to operate, and the impact on the water system is minimal. Fill that same bucket with a fire hose, and it will fill up very quickly, but the surge of water from a fire hose requires larger pipes and a more expensive hose. In the end, both buckets would be full with the same amount of water, but filling a bucket more slowly – smoothing the water use over time – creates less demand on the system and costs less to do.