Geomechanical Pumped Storage (GPS)
Quidnet Energy pioneered a novel form of pumped hydro that is widely deployable at very low cost called Geomechanical Pumped Storage. Subsurface rock layers are converted into energy storage facilities for large-scale renewables integration and grid management.
Pumped hydroelectricity storage without the need for mountains, lakes, or pre-existing underground caverns.
Structural cost advantage, with lower per-MW installed costs than even gas peaking plants.
Key process equipment provided and serviced by mature suppliers from well-established industries.
1-10 MW well modules for flexible and precise deployment onto the grid.
How does it work?
The entire system is built on conventional drilling technology and with off-the-shelf hydropower equipment. Facilities operate with closed-loop water systems, designed for conservation against evaporative loss, and regularly treated with disinfectants. The energy-storing rock bodies are non-petroleum bearing and found abundantly throughout the world, intersecting with major electricity transmission and distribution hubs.
When electricity is abundant, it is used to pump water from a pond down a well and into a body of rock.
The well is closed, keeping the energy stored under the form of water pressurized in the rock for as long as needed.
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 ready for the next cycle.
Frequently Asked Questions (FAQs)
Geomechanical pumped storage technology mimics conventional “pumped hydro” in its storage mechanism but doesn’t require large-scale dams and the costly civil works projects associated with them. Instead, geomechanical pumped storage relies on proven well drilling and construction technologies to pump water into subsurface geological reservoirs at elevated pressure to store energy.
Utilizing high-pressure water, we create a space between the horizontal layers of rock, much as you create a space between the covers when you slide into bed at night. This space extends outward from the center in a disk-like shape. Quidnet calls this our “Storage Lens.”
By pumping water under the pressure of thousands of feet of earth into this Storage Lens, we are able to store massive amounts of energy over long periods of time. When the energy is needed, the pressurized water is released to move power-generating hydro turbines.
Electricity is a unique product in that it is produced the moment you call upon it. When you turn on a light switch or plug in an iPhone, electrons race to you at 186,000 miles per second (virtually instantaneously) to supply your demand. Whenever you call upon it, somewhere a generator is ramping up to supply you with the additional electrons you’ve requested from the grid. The grid works by staying in perfect balance between supply and demand, with grid operators balancing this equation every five seconds.
Two of our most potent tools in the transition toward a zero-carbon producing electric grid are wind and solar power. These renewable power resources produce no emissions during operations and have a stable, no-cost fuel supply. However, the availability of wind and sun varies minute by minute. Periods of cloud cover or calm, windless conditions mean that supply can’t meet demand. As more and more wind and solar generation are added to the electric grid, more and longer duration storage is needed to keep it in balance.
To address this issue, leading researchers in the energy field have made energy storage the “Holy Grail” of solving our climate and energy challenges. This will be particularly important as other energy forms (transportation/buildings) transition to electricity as their primary energy source, putting significant additional demand on the electric grid.
While we mobilize the same workforce as the oil and gas industry to execute the work in the field, we are looking for very different rock layers: rock that is good for pressurized water storage is bad for oil and gas production and vice-versa.
As a consequence, encountering unexpected oil and gas would actually lead us to stop our operations in a given layer: it interferes with our water storage process, and any mixing of our storage water with oil or gas would result in a complex fluid mixture that requires costly separation equipment and reduces efficiency of the overall process.
Each 10 MWh of GPS, which would supply electricity to 1,000 homes for 10 hours each day, and will cycle 2 million gallons of water (5 Olympic swimming pools give or take). This water, minus what is lost on evaporation, is reused over and over in the closed-loop system. Due to the higher operating pressure, and thus energy density of the GPS process, the volume of water cycled in the GPS process is a fraction of the water cycled in a conventional pumped hydro storage facility.