Thermoechemical energy storage is a new approach that could finally breach the gap between concentrated solar power production and the grid.
Solar power is on the rise, which is, of course, what we all would love to hear. Technology is advancing, financial support is flowing, but no matter how great everything is, energy storage still remains the soft spot of the system.
Now, a team of researchers from Oregon State University, claim to have found the key to storing solar power for those crucial hours of the night. Their approach is called thermochemical energy storage (TCES), it is designed for concentrated solar power systems, it is cheap, it is clean, and it has equal energy storage density to conventional lithium-ion batteries.
TCES works in a similar manner to regular batteries, with the difference that the driving chemical reactions absorb and release heat during the charge-discharge cycles. It contains eco-friendly strontium carbonate (SrCO3) , which is nonflammable.
When TCES is implemented into a large-scale energy storage system, connected to concentrated solar power plants, the TCES uses the heat to break down SrCO3 into carbon dioxide and strontium oxide, stored separately within the system. For discharge, the two chemicals are combined again, and the process releases large amounts of heat, used to power a turbine. To make it even better, any residual heat that might be produces along the way, is also captured and used to drive another turbine.
According to the team behind the technology, the system is comparable to lithium-ion batteries in terms of volumetric density (1,450 MJ per cubic meter). Unfortunately, after 45 charging cycles, the capacity of the device at its current state drops by 15%.
The team is currently working on tackling this problem. If they manage, the system might finally meet the needs for an eco-friendly and affordable energy storage to serve a smart electrical grid.
More technical details can be found in the author’s publication in ChemSusChem, with lead author Nick AuYeng.
Image (C) ChemSusChem/Oregon State University
