With solar and wind energy becoming more important energy sources in Europe, countries are searching for new types of energy storage facilities. Some countries use hydropower as the least expensive method of storage, but this is only feasible in mountainous regions such as Norway. What if countries who don’t have the water source could use air?
The European Union and scientists from all over Europe are exploring this idea through a research project known as RICAS 2020. The main focus of the project is using sealed disused caverns as storage sites. The two largest compressed air stores in the world are in Germany and the USA.
SINTEF, the largest independent research organization in Scandinavia, is part of the research project. In a recent post, the organization explained that storing energy in compressed air is similar to using a bicycle pump. Bicycle pumps compress air to increase the pressure of the tires, which makes the pump hot.
“The more of the heat of compression that the air has retained when it is released from the store, the more work it can perform as it passes through the gas turbine. And we think that we will be able to conserve more of that heat than current storage technology can, thus increasing the net efficiency of the storage facilities,” says Giovanni Perillo, project manager for SINTEF’s contribution to RICAS 2020.
These underground chambers are created in salt formations, but these plants lose a lot of the potential energy of the compressed air because they lack a way to store the head produced during air compression.
The participants in RICAS 2020 believe they can reduce these losses with extra stations in which the hot compressed air passes through a separate cavern filled with crushed rock, which heats up the rock and the cold air is stored in the main cavern. When the air passes through the rock on its way to be used for electricity it’s reheated through the stones and then expanded through the turbine generating electricity.
SINTEF said this solution can offer better energy storage than batteries, and is therefore cheaper.
“If it turns out that our solution functions well, exciting new possibilities will emerge, not only for energy storage itself, but also for industrial applications of compressed air,” said Perillo.
Read more at SINTEF