Flow batteries are one emerging technology for storage of electrical energy. Development of large-scale flow batteries would enable storage of electricity created at off-peak times (mostly at night) and then supplied to the grid at peak (~noon-4pm) hours. Sources like wind generators or large electrical utility plants (that cannot totally shut down off-peak) would charge the flow batteries off-peak. Currently a large fraction of that off-peak energy production capacity is wasted.
There are several possible chemicals to use in flow batteries. Vanadium is popular, but, the few companies selling vanadium are limited on how much excess vanadium they could supply for flow batteries. Chrome-iron flow batteries use commonly available chromium and iron. Raw material suppliers should be able to supply large volumes of Cr-Fe at low prices for large scale use with utilities.
Work in 2012-13 has mostly been on the scale-up and design of a 1 megawatt-hr flow battery for Enervault.
It is an interesting electrochemical process that is similar, yet different from the electrochemical cells and equipment I designed and installed for 3M. The major equipment is on order and startup is planned for this fall in Turlock, California.
More details to follow.
Bloomdahl Engineering 