The ticket item in the energy transition is the efficient buffering of energy in order to overcome the intermittent nature of solar and wind. Old wells can help with that, as company Renewell from Bakersfield in California aims to do.
Only in North America, there are around 2 million idle oil and gas wells. With an average depth of around 5,700 ft or 1,750 m, these boreholes offer a greater vertical range than any building in the world can provide.
By fitting a weight consisting of old tubing and a high-density filling, occupying about a quarter of the length of the well, the company estimates that a single well has got a 168 kWh storage capacity. Implementing this simple technology to a significant part of idle US wells will result in a total storage capacity of 108 GWh, which is about 90% of the US’s energy storage needs by 2050 according to the company.
Not all wells will lend themselves for this solution because of the non-vertical nature of the hole. This may lead to friction and loss of efficiency.
At the same time as fitting the well with the Gravity Well technology, Renewell also aims to seal off the well to overcome the problem of methane leaks, an issue that contributes significantly to GHG emissions after well abandonment.
More information at: renewellenergy.com
