LI Bus' Battery Energy Storage System


Sodium and sulfur may not sound like a combination that can store energy and cut electricity costs, but that's exactly what a high-tech bank of batteries is doing for Long Island Bus.

Called the Battery Energy Storage System (BESS), this device is a collection of more than 6,400 sodium sulfur battery cells. When fully charged, BESS can supply one megawatt of electricity for approximately seven hours.

In use for the past year, BESS powers the natural gas compressor LI Bus uses to refuel its fixed route vehicles during the day. It automatically recharges itself at night when low-demand makes electric rates less expensive. BESS lets LI Bus improve its energy efficiency, reduce costs and provide emergency backup power.

This device is among the first and largest sodium sulfur cell technology installations in the United States. It also marks the first time this type of advanced battery technology is being used by a consumer with an electric meter. That's an important development because storing power based on this battery process has the potential to allow customers to capture energy from sources such as wind or tidal power. They can then use the electricity when it's most needed.

The entire project cost $4.3 million with about $2.4 million in funding coming from the New York State Energy Research and Development Authority, the United States Department of Energy, Sandia National Laboratories, the Electric Power Research Institute, the Long Island Power Authority, the American Public Power Association, the Canadian Energy Association, Natural Resources Canada and several other partners. In addition, the Petroleum Overcharge Restitution fund provided $300,000.

The MTA and NYPA have partnered on projects at MTA facilities resulting in energy savings totaling more than $9.6 million per year. These projects also annually save almost 11 megawatts of electricity and reduce CO2 emissions by about 40 metric tons.

LI Bus' entire fleet of 330 buses runs on compressed natural gas utilizing an environmentally responsible technology to transport 30 million riders annually.