Reposting: Don Sadoway on Energy Storage
February 25, 2014
Good discussions this week on the topic of new paradigms for utility grids and energy storage. I’m reposting Don Sadoway’s TED talk from 2012, because he has a promising technology for energy storage – that has continued in development by the startup Ambri.
Tech heavy stuff. Excerpts here – more details at the link. Experts weigh in.
The three layers in the Ambri battery are self-segregating, cheap to manufacture and earth-abundant. The materials used in the original design were magnesium and antimony separated by a salt — but “we needed higher voltage and lower temperature,” said the CTO, and so the firm has a new, undisclosed chemistry arrived at with the help of ARPA-E funding.
Prototype units started as the “shot glass,” followed by the 3-inch, 20-watt-hour “hockey puck,” and then by the 6-inch, 200-watt-hour “saucer.” The commercialized product will use a 6-inch square.
Bradwell notes that the batteries achieve 1,000 cycles of continuous deep cycling with negligible fade. There are no moving parts, pumps or valves in the design.
The cell is contained in a 4-inch-by-4-inch stamped stainless steel housing with no nanoscale microstructures or difficult-to-synthesize materials, according to the co-founder.
The cells have a DC-to-DC efficiency of 80 percent at a five-hour charge/discharge rate and an AC-to-AC efficiency of 70 percent to 75 percent.
Ambri hopes to have its first scaled 20-kilowatt-hour units operational early this year, with 35-kilowatt-hour commercial units coming in 2015. A larger system will reach 200 kilowatt-hours in 3 cubic meters. The 10-ton weight of that unit will serve as an effective theft deterrent, joked Bradwell.
In an earlier presentation at this event, Tad Glauthier, VP at storage system vendor Stem, cited Ambri and Aquion as new battery vendors with potential price-competitiveness. He noted that improvements in lithium-ion technology are small and incremental, while changes in battery technologies’ price points have the potential to change the size of the market. Glauthier sees near-term battery price reductions reaching one-half to one-third of lithium-ion, falling to sub-$100 per kilowatt-hour levels before 2020.