Researchers want to store surplus renewable energy in the form of methane

Their idea is to use microbes to convert the excess renewable energy into methane, which could be burned if necessary. In nature, the microorganism Methanococcus maripaludis consumes hydrogen and carbon dioxide and releases methane. Researchers therefore use renewable energy electrodes to split water and release its hydrogen atoms. These hydrogen atoms feed the microbes, which draw carbon dioxide from the air and release methane. The gas does not dissolve in the water, so it can be captured and stored.

Then, during peak demand or when renewable energy does not produce, methane can be burned in the same way as fossil fuels. Transforming renewable energies into methane, which releases carbon dioxide when it burns, may seem like a backward task. But this methane is produced by extracting carbon dioxide from the atmosphere, making the process carbon neutral. A significant advantage over battery-based storage systems, such as Tesla Powerpacks, is that methane can be converted to electricity using existing infrastructure.

Researchers are still working on technology, but believe that it can be profitable on a large scale. The Ministry of Energy has already committed funds and the National Laboratory Lawrence Livermore and Southern California Gas are helping to develop more efficient designs. It's hard to say if this can solve the biggest defect of renewable energy – its storage problem – but it's certainly a new approach.