A team from the Massachusetts Institute of Technology (MIT) has reinvented an ancient technology for modern use.
Researchers wanted to find a way to use or store excess renewable electricity generated when demand is low, and rediscovered the idea of the firebrick.
Firebricks were first used by the Hittites, a civilization that occupied modern-day Turkey around 1600 BC. They are made to tolerate high temperatures and retain heat for a long time if insulated.
Heat stored by firebricks can be used straight away or converted back into electricity at a later time.
Charles Forsberg, lead author of the MIT research paper, has dubbed the system FIRES (Firebrick Resistance-heated Energy Storage) and said there was a constant demand for industrial heat, creating an "almost limitless market" for the technology.
Forsberg claimed that FIRES could raise the minimum price of electricity in the utilities market, which at present can dive to almost zero at times of high production and low demand.
He added that the cost of firebrick thermal storage would be about a fortieth of the cost of storing electricity in batteries or expending it on a pumped hydroelectric system, two of the existing ways of storing excess renewable power.
The team plans to create full-scale firebrick storage system before 2020 to test their idea in real-world conditions.
Regis Matzie, a former chief technical officer at Westinghouse Electric, who was not involved in the research, said: "I believe FIRES is an innovative approach to solve a real power grid problem.
"The current skewed electricity market produces low or even negative market prices when a significant fraction of electrical energy on the grid is provided by renewables.
"A very positive way to correct this trend would be to deploy an economical way of storing the energy generated during low electricity market prices, such as when the renewables are generating a large amount of electricity, and then releasing this stored energy when the market prices are high.
"FIRES provides a potentially economic way to do this, but would probably need a demonstration to establish the operability and the economics."
Images courtesy of MIT
