siemens announced in september that it is working with engineers from the institute of thermofluid dynamics at the technical university of hamburg, germany on an economic storage technology to better harness the power of wind energy.

siemens is trying to produce a more efficent storage for wind energy. (siemens)

the process begins with converting excess wind energy to heat in rock fill before being stored behind an insulated cover. when the excess energy is needed, it is converted back to electricity by a steam turbine, according to a press release from the company.

the storage technology is being tested to optimize the efficiency of the conversions. the press release noted, “just like a hot air gun, a fan uses an electrically-heated air flow to heat the stones to the desired temperature. when discharging, the hot stones in turn heat the air current, which then heats a steam boiler; its pressure drives a generator via a steam turbine.”

at the present time, no reverse current is generated, as the system is being tested for its thermal management with temperatures as high as 600°c. the goal is to test a complete system by 2017 in which the energy is turned into heat and then converted back. the full-sized future energy solution (fes) will be able to store as much as 36 mwh with 2,000 cubic meters of rock and hope to build effectiveness from 25 to 50 percent.

"the technology of our fes store deliberately uses mainly tried and trusted technology," said till barmeier, siemens' project manager, in the press release. "because we are working here with tested thermal components and a series-ready steam turbine, we will be able to offer a practical solution within a few years. our complete experimental system will be operational in just around 15 months."