No matter how appealing solar energy sounds, there are host of problems associated with it that are yet untackled and shine directly in our face as we try to research on the renewable energy topics. One such problem is of the Solar Energy storage. Once the Sun goes down, the existing solar energy technology is not able to meet the demand because of lack of storage. So now, Terrajoule - a start-up from California has come up with a solution to using the old technology of steam engines. Interestingly, using steam engines they've been able to lower the cost of building the storage system to less than $100 per kWh, which is less than 20 percent of what it costs for current battery storage systems.
So, how does it work? Solar concentrators produce steam - and Steam engines convert the solar power in steam to electricity. Energy storage is achieved via a “steam accumulator” built with insulated steel pressure vessels and filled with water. Since it is impractical to store gaseous steam for later use, the steam is condensed into the mass of water where its energy is stored. When needed, the stored energy flashes the water back to steam. The energy lost in this steam-water-steam phase change cycle is less than 2%.
What do electrical engineers think about the solar energy storage issue and the probable solutions? - Speak up in comments.