High Pressure Water Energy Storage Coming To San Antonio

A “battery” is any device that stores electrical energy so it can be used later. To Elon Musk, a battery is cylindrical device with an anode and a cathode inside. It is a pretty effective energy storage device, but but can only supply power for about 4 hours.

Pumped hydro is another energy storage solution. Pump water uphill when demand is low; let it flow downhill to spin turbines when demand is high. In theory, the water can remain in the upper storage area for weeks or even months, but the total energy available is limited by how large a volume of water is stored.

Quidnet Energy is one of many companies being backed by Breakthrough Energy Ventures, the energy innovation organization founded by Bill Gates. It takes the fracking technology developed by the oil and gas industries and repurposes it to store energy. Here’s how the company describes the process, which it calls “geomechanical pumped storage” or GPS.

“Geomechanical pumped storage uses the rock beneath our feet as a sustainable natural resource. Quidnet’s patented GPS technology utilizes excess renewable energy to store water beneath ground under pressure. When renewable energy is not producing, this pressurized water drives hydroelectric turbines producing electricity to support the grid at a fraction of the cost of Li-ion and for much longer duration. Quidnet’s technology is an adaptation of centuries-old gravity-powered “pumped storage,” but without the massive land requirements and reliance on elevated terrain.”

Here’s a video that explains how the Quidnet GPS system works.

Quidnet GPS Energy Storage For San Antonio

CPS Energy, which serves nearly a million utility customers in and around San Antonio, is committed to lowering its carbon emissions 80% by 2040. It is one of the largest users of electricity from wind and solar in Texas, but needs long term energy storage to complete its renewable energy portfolio. This week, it announced a 15-year agreement with Quidnet Energy to use the company’s GPS technology to store excess electricity.

In a press release, CPS Energy says the project will be developed in two phases, starting with an initial 1-megawatt, 10-hour storage facility. The 15-year agreement will allow time for both parties to explore and refine the new technology, which pumps water underground and stores it between impermeable rock layers. The rock acts like a natural spring to hold the water under pressure. When called upon to supply electricity, the pressurized water is released to power a hydroelectric turbine that generates emission free electricity. The entire process is closed loop to conserve water resources. CPS Energy will have the option to expand the project to provide 15 MW as the project matures.

Quidnet say its GPS technology “unlocks the constraints of traditional pumped hydro to fundamentally change the economics and deployment profile of long duration storage.” A GPS system costs half of what traditional battery storage costs and is suitable for many locations where pumped hydro storage is not practical. Because it relies on fracking technology that is common in the oil and gas industry, it provides new employment opportunities for workers in those industries. Quidnet is developing energy storage sites in several parts of Texas as well as in Ohio, New York, and Alberta, Canada.