If you have been following my blog I think you will know that a key challenge to bringing renewable energy to mass market is storage. We have the ability to generate a huge amount of cheap solar energy during the day time, but we really struggle to deliver it at night time. One approach to solving this lies in battery storage. Battery storage has a lot of potential (no pun intended), but we are not able to store municipality levels of energy in batteries yet. Another method that is being tested to store energy is using compressed air. The idea is that we can compress air with electricity generated by solar panels during the day, and release it across a turbine at night time.
This is a clever idea and it does actually work. The problem is that every time we convert energy we lose some efficiency. Air compressors have notoriously low efficiencies which can be between 65% and 80%. This means that for every 10 KW you put into compressing air, you only get about 7 KW of usable air. At this point a reader might ask, “I thought we can’t create of destroy energy, so where does the rest of the energy go?” Great question, I’m glad you asked. You are correct that we can’t destroy energy in reality most air compressors lose a lot energy in the form of heat. All of the energy that is lost in the process of compressing and expanding air across a turbine makes it hard to remain economical.
But all hope is not lost for this method of storing energy. An innovative company called LightSail Energy seems to have figured out a better way. LightSail Energy uses technology that both compresses air for later use, and captures and stores the waste heat for later use. By capturing and storing the heat, LightSail is able to greatly increase the efficiency of the process. Which means they are able to make this type of project much more economical. Another nice thing about compressed air energy storage is that you can scale it up by storing air in large underground caverns.
This company really understood the root problem and came up with a viable solution to solve it. Keep an eye out for LightSail Energy in the future because they are doing a lot of things right. They recently received large rounds of funding from big investors including Bill Gates.
If you have any thoughts on this innovative new technology please share them in the comments section.