Energy storage in mine explained

Pyhäjärvi pumped hydro energy storage actually use more power than they generate. Yet it could play a key role in Finland’s’s future energy network.

Why it is needed?

As more coal and other old power stations retire and more intermittent renewables enter the energy market, something is needed to help fill the gaps when sun is not shining and there is no wind. In those scenarios we need to balance out the volatility with reliable, adjustable power and this is where pumped hydro energy storage can really make a difference.

How it works?

It is like creating a big battery. When there is excess power in the energy system, for instance on a windy nights, this energy can be used to pump water up to upper reservoir from the mine like “load a battery”. Then when there is demand for energy in the system, the water is released. As it falls to mine, it turns turbine and generator that “create the power” and the lower water reservoir is filled up.

Please take a look the below video: Pyhäjärvi energy storage in mine explained