Of all the energy storage solutions I’ve heard of, batteries / molten salt / pumped hydro, compressed air is certainly not one that would have occurred to me.
Compressed Air Energy Storage (CAES) works by using a renewable energy source (solar, wind, etc) to pump and compress air into a vessel when the sun is shining or when the wind is blowing. It then sits in the vessel until it is needed at which point it is released in a controlled manner and used to spin a turbine to create electricity.
Now this is where it gets interesting. Releasing compressed air consumes an incredible amount of heat and freezes everything in its path, including the turbine. Think of when you’ve used a can of compressed air to clean your computer. Even a small amount like that compressed air can gets really cold, really fast.
So how do they address the freezing? If releasing compressed air freezes things then compressing air must generate heat. It does, and lots of it. During the compression process the heat gets collected and stored in its own vessel. Then it is released in a controlled manner during the compressed air release. By balancing the rate of air decompression with the release of heat into the turbine, the system stays at its proper running temperature and all is well with the world.
CAES offers an ingenious way to produce, store and release electricity in a closed loop system using 100% renewable sources. This is another great option in the fight against climate change.
Matt Ferrell has a great video that explain CAES in more detail.
