As the problems caused by climate change, carbon dioxide emissions and the energy storage conundrum rise, researchers at Lawrence Livermore National Laboratory have come up with a way to combat them. The subsurface energy system they have developed could tap geothermal energy, store energy from above-ground sources, and dispatch it to the grid throughout the year like a massive underground battery.
Since the Paris climate agreement in December 2015, pressure has been mounting to try and find alternative ways of generating energy that don't pollute the atmosphere.
Capturing and storing waste CO2 underground is a potential solution for the greenhouse gases created when fossil fuels are burned, but this approach has proven costly and tricky to accomplish. Challenges include the high cost of capturing CO2, overpressure caused by storing huge quantities of CO2, and controlling where the gas goes.
Meanwhile, there also remains the long-term dilemma of renewable energy sources such as solar and wind power being unable to provide energy when the sun isn't shining or the wind isn't blowing. People want clean energy, but they don't want to compromise on their energy needs.
A solution for intermittent renewables?
Scientists at the Lawrence Livermore National Laboratory (LLNL), Ohio State University, the University of Minnesota and tech firm TerraCOH think they've found the solution to both these problems by coming up with a way of storing CO2 underground as a supercritical liquid - with properties similar to a liquid - and then using it for other purposes. The team's paper, titled Earth Battery, was published in Mechanical Engineering magazine and it puts forward an underground battery concept which is fuelled by waste carbon dioxide and stores energy to be supplied to the grid when needed.