Can we store energy for months together?

Most batteries are capable of storing energy efficiently only for a few hours.

But there are situations where energy needs to be stored for months together.

Take a city in a cold region in Europe. The city might want to capture the heat from sunlight during the summer and use that for home or district heating in winter. But winter could be six months away from the time the unit of energy was captured from sunlight.

Are there systems that can store the energy for many months together?

Yes. While different solutions are emerging for medium and long term energy storage, it is already proven that underground energy storage systems can store heat efficiently long enough to last for the next season. These underground locations might be in the form of boreholes, caverns, pits or aquifers.

A community in Alberta, Canada has seen significant success in the use of underground heat storage between seasons. The underground storage of heat captured during summer is fulfilling more than 90% of each home’s space heating requirements in winter, resulting in reduced use of fossil fuels.