Published on February 21st, 2013 | by Nicholas Brown2
LightSail Gets $5.5 Million For Compressed Air Energy Storage
LightSail Energy, a utility-scale energy storage company, has obtained $5.5 million from investors to fund its compressed air energy storage (CAES) project in the second closing of its $37.3 million Round D.
The investors include Bill Gates; Peter Thiel, an early Facebook investor and co-founder of Paypal; Total, a very large French energy company; Innova Corp; and Khosla Ventures.
Bill Gates, the co-founder of Microsoft, is definitely interested in alternative energy (including nuclear), but Peter Thiel flat-out said at one point that cleantech venture capital is a “disaster” and that alternative energy startup companies are wasting taxpayers’ money.
I mentioned his comments on alternative energy because energy storage is particularly important to wind and solar. It enables them to be deployed in a more economical manner if cheap enough.
Thiel’s comments against cleantech investment are apparently a thing of the past, though. Peter Thiel has come around to fund this CAES company, which aims to improve the efficiency of compressed air energy storage systems.
Compressed air energy storage systems store energy by using it to compress air in a tank, which can then be released so that it rushes through a generator to re-acquire it. LightSail said that the thermal efficiency of compressed air energy storage systems can be improved from 60% to 90% using the startup’s alternative concept.
Thermal efficiency is defined as how much of the energy that was supplied to the system was actually stored, rather than wasted as heat.
LightSail’s concept sprays water into an air tank to cool the hot, compressed air, since the water will absorb its heat, and then that warmed water is transferred to a tank for storage. The warm water is then used to reheat the compressed air to increase its pressure, and hence increase power production when it is needed.
A 50 litre (13 gallon) tank is required to store 1 kWh of energy. This has a volumetric energy density well below that of all the batteries on the market (in other words, it is bigger). However, U.S. Energy Information Administration studies have shown that compressed air energy storage is cheaper than batteries.
Source: Greentech Media