Although electricity storage is the holy grail for generators and transmissions firms, the steps to get there don’t come without some hiccups.
Compressed air systems cannot be reversed to power production from power storage in the milliseconds the industry would like, and below-ground storage sites are often not in locations close to major conurbations, while above-ground storage is not a major attraction in residential areas for obvious reasons. Sodium-Sulfur, while a vast improvement on Lead Acid and Lithium Ion, is still an expensive storage technology, which accounts for its slow uptake so far.
An old technology highly refined is purporting to have the answer, according to the NY Times. Eos, a US firm, has refined the Zinc Air battery to the point where in tests, batteries are exceeding 10,000 cycles and life expectancy of 30 years is a realistic expectation.
Overcoming the traditional degradation experienced in zinc air batteries by developing new electrolytes and patented cell designs, the firm is working with power generators to develop scalable products that could be in service by 2014.
Early devices are the size of a small refrigerator, but eventually standardized 40-foot container plants capable of storing MWs of power are planned, crucially at a low installed cost of about $160/kWh, less than providing natural gas-powered peak power production capacity and significantly below other battery technologies, which are in the $400 to $1,000/kWh range.
As the manufacturer Eos points out, zinc is a relatively low-cost metal widely available both domestically and from friendly sources such as Canada and Australia. Zinc batteries do not catch fire like Lithium Ion have done on occasion, nor do they contain toxic chemicals. Residents in built-up areas may therefore happily co-exist with a 40-foot container or two discreetly placed in the neighborhood in return for consistent power supply, come summer heat or winter freeze.
We will watch the trials with interest.