Connexus Energy has begun construction on two solar-plus-storage projects that it says will be first large-scale battery projects in Minnesota and the largest storage installations for an electric cooperative in the United States.
The projects, totaling 10 MW of AC solar and 15 MW/30 MWh of energy storage, are estimated to cost $31 million and save $4 million annually through peak load reduction. Connexus has been in negotiations to begin the project since last year.
Solar-plus-storage could be more cost effective than natural gas peaker plants in Minnesota as soon as this year, a study from the University of Minnesota concluded in 2017. The report also cited a study by Connexus that found a majority of its members "were willing to pay up to 5% more for efforts to reduce greenhouse gas emissions and increase renewable energy."
The Connexus projects join a larger trend of solar-plus-storage installations popping up across the country as the price of the resources decreases and utilities seek emissions-free alternatives to natural gas plants.
Battery storage is anticipated to reach 557 MW by the end of 2018 and near 1 GW by 2019, according to GTM Research.
Minnesota has been at the forefront of community solar laws in recent years, building 246 MW of privately developed community solar, thanks in part to a highly anticipated regulatory decision by Minnesota lawmakers in 2015.
"The holy grail for renewable energy is to have storage you can dispatch at any time," said Ellen Anderson, executive director of the University of Minnesota's Energy Transition Lab to the Minneapolis Star Tribune. The Star Tribune also noted that other utilities around Minnesota, including Xcel energy, are keeping a close eye on the project, "as batteries are viewed as increasingly important to the electric grid of the future."
The Connexus facilities will supply energy to 7,000 homes between their locations in Ramsey and Isanti Counties. The storage units are being developed by NextEra Energy, while the solar plants will be built by French energy firm Engie, according to the Star Tribune. The utility has a 25-year power purchase agreement with Engie and a 25-year storage commitment with NextEra.
Ramsey, Minnesota, the headquarters of Connexus Energy, will not only be home to the largest energy storage co-op in the U.S., but is also home to the first integrated bee farm and solar facility in the U.S.
Correction: In a previous version of this article the energy lab was misidentified. It is actually the University of Minnesota Energy Transition Lab.