A new technology called Underground Gravity Energy Storage turns decommissioned mines into long-term energy storage solutions to support a sustainable energy transition.
Renewable energy sources are central to the energy transition towards a more sustainable future. However, energy sources such as sunlight and wind are inherently variable and inconsistent, so finding ways to store energy in an accessible and efficient manner is critical. While there are many effective solutions for everyday energy storage, the most common being batteries, cost-effective long-term solutions are still lacking.
In new research led by IIASA, an international team of researchers has developed a new method of storing energy by transporting sand to abandoned underground mines. A new technology called Underground Gravity Energy Storage (UGES) offers an effective long-term energy storage solution while tapping into potentially millions of mining sites around the world.
UGES lowers sand into underground mines when prices are high, converts the sand’s potential energy into electricity via regenerative braking, and uses electric motors to lift sand out of the mines and into upper reservoirs when electricity is cheap. to generate electricity. The main components of UGES are shafts, motors/generators, upper and lower storage sites, and mining equipment. The deeper and wider the mine shaft, the more power can be extracted from the plant, and the larger the mine, the higher the energy storage capacity of the plant.
“When the mines close, thousands of workers will be laid off. This will devastate communities that depend solely on the mines for their economic output. It will create some vacancies to provide storage services,” said Julian Hunt, a researcher in the IIASA Energy, Climate and Environment Program and lead author of the study. “The mine already has basic infrastructure and is connected to the power grid, which greatly reduces costs and makes the UGES plant easier to implement.”
Other energy storage methods, such as batteries, lose energy through self-discharge over long periods of time. Since the energy storage medium of UGES is sand, there is no energy loss due to self-discharge, and ultra-long-term energy storage of several weeks to several years is possible.
The investment cost of UGES is about 1-10 USD/kWh and the power capacity cost is 2.000 USD/kW. The technology is estimated to have 7-70 TWh of potential globally, with most of this potential concentrated in China, India, Russia and the United States.
“To decarbonize the economy, we need to rethink our energy system based on innovative solutions using existing resources. Turning abandoned mines into energy storage is all around us. It’s just one example of many solutions that we can deploy that just need to change how we deploy them,” concludes study co-author Behnam Zakeri, a researcher in the IIASA Energy, Climate, and Environment Program. increase.
Original: turn an abandoned mine into a battery
Than: International Research Institute for Applied Systems Analysis
