The alledged lack of utility size storage has always been the coal and gas minions excuse to the public for distrusting alternative forms of energy. It also has never been true. One of the easiest storage system was proposed in the 50s. That would be pumping water up hill to a reserve and then at night letting it run down hill through a turbine. This creates a complete energy loop that could in theory last forever. Another proposed in the 70s was to heat molten salts and then extract the heat later. The one that always excited me the most was actually proposed in several different places and times; and was actually proposed to capture lightening. All it is is a giant battery in the ground which uses the earth as an insulator. But now that the tech guys are getting into the act, I am sure the utility companies will just throw up their hands and toss in the towel.
http://cleantechnica.com/2012/02/18/new-flow-battery-does-that-cheap-energy-storage-thing/
New “Flow” Battery Does that Cheap Energy Storage Thing
Scientists on the lookout for utility-scale, high efficiency batteries are developing new “flow”systems that that store energy more effectively than lead-acid or lithium-ion batteries, but there’s a catch. The flow batteries in operation now are about the size of a house and they cost more than the equivalent in lithium-ion batteries. The race is on to find smaller, cheaper alternatives and researchers at Sandia National Laboratories believe that they are on to the solution, which is, in fact, a solution of liquid salts called MetILs.
The limits of lithium-ion for wind and solar
Lithium-ion batteries have been the gold standard of energy storage solutions for a long time, but they fall short when it comes to the utility-scale systems needed to keep up with new high efficiency wind turbines and advanced solar technology. The cost of lithium-ion batteries is one factor. Another is their relatively short lifespan, compared to flow batteries. According to Sandia chemist Travis Anderson, a flow battery can withstand about 14,000 cycles, which adds up to about 20 years of energy storage.
Flow battery basics
Flow batteries work by converting chemical energy into electricity. Stephanie Hobby of Sandia explains it thusly:
“A flow battery pumps a solution of free-floating charged metal ions, dissolved in an electrolyte — substance with free-floating ions that conducts electricity — from an external tank through an electrochemical cell to convert chemical energy into electricity.”
Flow batteries charge and discharge rapidly, and they have a long lifespan, but all is not perfect in flow battery land. The most promising systems so far use zinc bromine and vanadium, both of which are “moderately toxic” according to Hobby. In addition, the price of vanadium can spike wildly on the open market.
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Go there and read. More tomorrow.
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