Urban Electric Power -- a small New York City startup -- is hoping it has the next big solution in energy storage.
Formed last May by researchers from the City University of New York (CUNY) Energy Institute, Urban Electric Power is taking breakthroughs in battery technology from the lab to the market -- technology that was initially developed with funding from the Energy Department. The company’s low-cost, lead-free zinc anode rechargeable batteries are designed for a wide range of applications in the growing energy storage market -- from reducing peak energy demand in urban areas to storing variable renewable energy for future use.
Inexpensive, non-toxic and widely available, zinc has long been known to be an excellent electricity storage material because of its high energy density. Invented more than 100 years ago, the zinc anode battery is still used today. Yet, for all its benefits, zinc has one major shortcoming -- dendrite formation develops over the battery’s life, causing the battery to short after a few hundred cycles. This dendrite formation -- or buildup of zinc deposits -- significantly reduces the life of zinc batteries, making them too expensive for large-scale applications like grid storage.
With industry and government funding -- including a grant from the Energy Department -- the CUNY Energy Institute began developing innovative solutions for this problem in 2008. The result: a zinc-nickel oxide battery in which the electrolyte circulates constantly, eliminating dendrite formation and preventing battery shortages. This breakthrough helped the CUNY Energy Institute create a zinc battery that has a round trip efficiency of 85 percent, and can be charged and discharged more than 5,000 times.
Over the past year, Urban Electric Power has worked to scale up manufacturing of this technology while driving down its price -- making the zinc-nickel oxide battery a quarter of the cost of conventional lead-acid batteries per cycle. In June, the CUNY Energy Institute and Urban Electric Power unveiled part of a 200 kilowatt installation of their zinc-nickel oxide batteries at the City College of New York’s Steinman Hall. The batteries will be used to reduce the building’s peak electricity demand by 10 percent.
Building on lessons learned from the zinc-nickel oxide battery, the CUNY Energy Institute received funding from ARPA-E to develop a zinc-manganese dioxide battery for grid-scale storage -- essentially a larger, rechargeable version of the disposable alkaline batteries we use in our daily lives. The CUNY Energy Institute researchers were able to create a zinc-manganese dioxide battery that is half the weight and five times the life of a lead-acid battery, without the manufacturing, handling and recycling costs of lead-acid batteries. Urban Electric Power hopes to offer these batteries on an industrial scale by 2014, and once fully scaled up, the zinc-manganese dioxide battery will be even more cost-effective than the company’s zinc-nickel oxide batteries.
Watch the video above to learn how researchers overcame the technical challenges with making zinc rechargeable, and what this breakthrough means for the future of grid-scale energy storage.