A new zinc-nickel oxide (Zn-NiO) rechargeable battery system is currently being shifted from a 30kWh lab demonstration for peak shaving to a 100kW sub-system for the smart power grid on the City College of New York campus.
The GreenCat system uses flow-assisted batteries with nickel oxide cathodes are able to recharge for over 5,000 deep cycles while still retaining more than 80% of their capacity, necessary for grid-scale energy storage which requires batteries with low lifetime costs per kWh. The batteries are suitable for peak shaving, peak shifting, power protection, forklift operations, and solar and wind firming.
The system performs similar to a lithium ion battery, but at the price of a conventional lead acid battery per delivered kWh. They are also safe, non-toxic, recyclable, and operate without capacity loss for many years and without the need for special handling or cooling equipment.
Developed by the CUNY Energy Institute, the Department of Energy, NYSERDA, and Con Edison, the GreenCat system was exclusively licensed to Urban Electric Power (UEP). This is the first stage of a 110kW/200kWh system to be completed by the end of July 2013.