New York recently strengthened its power supply with the completion of two projects: an underground and underwater 660-megawatt electric transmission project between New Jersey and Manhattan and a low-cost, commercial battery-storage system on the campus of the City College of New York (CCNY).


The Hudson transmission project recently completed testing and has begun delivering power to customers in New York. Starting in Ridgefield, N.J., it has a route of about 7.5 miles, with a cable bundle under the Hudson River for about 3.5 miles and the rest buried underground. The line is capable of providing about 5 percent of the city’s peak demand. Electricity drawn from the PJM grid is converted from alternating curent (AC) to direct current (DC). At a new station, it is converted back to 345 kilovolts (kV) AC for underground and underwater transmission to ensure reliability and controllability.


Construction began in May 2011 at a cost of some $850 million and was completed six weeks ahead of schedule, despite the two hurricanes that hit the area during construction. The Hudson project demonstrated how this technology can bring reliable and timely electric power to densely populated areas.


This low-cost battery-storage facility designed for the smart grid is currently being powered up as a 100-kilowatt (kW) subsystem on the CCNY campus. It is the first stage of a 100-kW/200-kilowatt-hour system scheduled to be completed this summer.


Cost-competitive grid-scale energy storage for peak shaving, renewables firming, transmission and distribution deferral requires batteries with much lower lifetime costs per kilowatt-hour than has been previously available. For the past 10 years, researchers have worked to develop battery technologies that can compete in these markets.


Urban Electric Power’s zinc anode battery technology is the first of these to transfer from the lab to market. The new GreenCat zinc-nickel-oxide rechargeable-battery systems are able to meet ambitious cost targets because they are capable of achieving many more cycles than previous generations of zinc anode batteries. These new zinc anode batteries provide performance similar to a lithium-ion battery for the price of a conventional lead acid battery per delivered kilowatt-hour. Zinc anode batteries are safe, nontoxic, 100 percent recyclable, operate without capacity loss for many years, and do not require special handling or cooling equipment.


The CUNY Energy Institute developed the storage technology. This technology had been in operation for more than a year as a 30-kWh lab demonstration used for peak shaving.