Danish factory stores electricity as methane

German firm Electrochaea built a factory in Copenhagen, Denmark, where microbes convert electricity into natural gas.

Electricity is used to split water into hydrogen and oxygen. The hydrogen is combined with carbon dioxide (CO2)  to make methane. The methane can be stored, or sent to gas users through existing pipe systems.

Electricity is easy to generate but hard to store efficiently. The main problem with solar and wind power is that they are not reliable and constant.

When that electrical energy is converted to the chemical energy contained in methane, it can be stored indefinitely and used whenever needed.

The technology is based around microorganisms called archaea which naturally create methane from CO2. Arcaea occur naturally around volcanic hot springs and in animals’ digestive systems. They are the microbes that make such potent methane sources. Electrochaea has found a way to harness this process.

Electrochaea CEO Mich Hein said the plant makes it possible to “store large amounts of energy in the gas grid, which is really the biggest battery that we have already built.”

A secondary benefit is that the process could actually remove CO2 from the atmosphere.

“There’s a large amount of interest in this technology for also being able to recycle and store carbon as a combustion fuel that can be used clean, essentially replacing fossil fuels with a renewable energy and making use of all the infrastructure we have available to us for combustion,” he said.

The biggest benefit beyond the clean energy source is that there is already a storage and delivery system for gas, and there are power plants already set up to burn it.

This makes the natural methane a cheap as well as cleaner alternative that is ready for immediate use.