CPS Energy In Texas Signs Deal For Underground Pumped Storage Project

by Peter Maloney
APPA News
March 9, 2022

CPS Energy, the public power utility serving San Antonio, Texas, has signed a deal with Quidnet Energy for a pumped energy storage project that could eventually be as large as 15 megawatts (MW).

The 15-year agreement calls for an energy storage project employing Quidnet’s geomechanical pumped storage (GPS) technology. The plan calls for the project to be developed in two phases, starting with a 1-MW, 10-hour storage facility.

Quidnet’s technology uses off-peak electricity to pump water from a holding pond into an impermeable rock under the ground where it is held under pressure until the pressurized water is released to power a hydroelectric turbine. The closed loop process is designed to conserve water by reusing it and minimizing evaporation.

The technology employs much of the same expertise, workforce, and supply chains that are used to drill for oil and gas, and it uses conventional drilling technology and off-the-shelf hydropower equipment, Quidnet said. The technology can also be deployed across a diverse range of geographic locations and be scaled by using modules that go from 1 MW in size up to 10 MW, the company said.

“Incorporating Quidnet’s homegrown-Texan energy storage solution allows us to create a cleaner electric supply while supporting our local energy industry workforce and lowering costs for our customers,” Rudy Garza, interim president and CEO of CPS Energy, said in a statement.

CPS Energy also said the energy storage project would support its Flexible Path Resource Plan that aims to reduce the utility’s net emissions by 80 percent by 2040.

Under its Flexible Path Resource Plan CPS Energy’s intends to close coal plants, integrate technologies like energy storage and electric vehicles, expand the use of renewable resources, and add more programs and services such as energy efficiency and demand response. CPS aims to increase its renewable resources by 127 percent by 2040 while decreasing gas- and coal-fired generation by 72 percent and 61 percent, respectively.

Last year a Department of Energy study found that hydropower, including pumped hydro storage facilities, could be critical to ensuring the reliability of the nation’s electric grid during extreme weather events.

Quidnet has developed energy storage test sites in Medina and San Saba counties in Texas and is working on pilot projects in Ohio, New York, and Alberta, Canada. In addition to venture capital backing, Quidnet has received support from the Department of Energy, the New York State Energy Research and Development Authority, and Emissions Reduction Alberta.