San Antonio-based CPS Energy signed a 15-year commercial agreement with Quidnet Energy for a 1 MW, 10-hour energy storage facility using geomechanical pumped storage technology. Following initial deployment, the municipal utility has the option to expand the project to 15 MW.

The technology is based on conventional drilling technology used in the oil and gas industry as well as off-the-shelf hydropower equipment. When low-cost electricity is available, water in a storage reservoir is pumped down a well and into a body of rock. The energy-storing rock bodies are non-hydrocarbon bearing and found in many locations, including near electricity transmission and distribution hubs. When electricity is needed, the well is opened to let the pressurized water pass through a turbine to generate electricity, and return to the pond for the next cycle.

This article was originally published on sister website Power Engineering.

The approach makes use of approaches and supply chains used in the oil and gas industry, Houston-based Quidnet said, and provides a possible “pathway into the green economy” for oil patch workers.

Quidnet has developed energy storage test sites in Medina and San Saba counties in Texas. It said it is working on pilot projects in Ohio, New York, and Alberta, Canada. The company is backed by Breakthrough Energy Ventures, Evok Innovations, Trafigura, and other investors and has received support from the U.S. Department of Energy, New York State Energy Research and Development Authority, and Emissions Reduction Alberta.

The company said that each 10 MWh system would cycle water equivalent to about five Olympic swimming pools, or around 3.3 million gallons.

CPS Energy adopted its Flexible Path Resource Plan to close coal plants and adopt technologies like energy storage and electric vehicles, expand renewable resources, and add more programs and services such as energy efficiency and demand response. By 2040, the utility plans to increase renewables by 127% while decreasing gas- and coal-fired generation by 72% and 61%, respectively.

EPIcenter’s Innovation Management program was engaged to support CPS Energy’s decision-making process for this novel form of energy storage. The program facilitates the process alongside a team of CPS Energy leadership to vet and implement emerging technologies. The nonprofit organization, established in 2015, is intended to speed innovation to make the production and consumption of energy smarter, cleaner, more resilient and more efficient.