Strategic Us e of Fuel Cells
Published In: EnergyBiz Magazine September/October 2013
The U.S. Department of Energy released a report recently that stated that the nation's entire energy system - the grid and all of its associated parts - is vulnerable to severe and costly weather events and that energy disruptions such as those caused by Hurricane Sandy are just the beginning.
"What we've learned from Hurricane Sandy and other disasters is that we've got to build smarter, more resilient infrastructure that can protect our homes and businesses, and withstand more powerful storms," President Barack Obama said recently."
So how do Dominion and other energy companies find ways to improve the resiliency of the nation's grid? What do we need to build today to prepare for an ever-changing future, to keep the lights on and get them back on faster after a natural disaster?
One of many possible answers is being built today on what was an empty lot in downtown Bridgeport, Conn. It is our newest "smart grid green" power station that holds a promise of 24/7 reliable energy, but doesn't depend on fuel combustion or those other familiar but intermittent green power sources such as sun or wind.
The new entry is the Dominion Bridgeport Fuel Cell Power Station, which will be in operation by year's end. Its progress is easily visible to the millions of people who drive along Interstate 95 and travel Amtrak's Northeast Corridor between New York City and Boston. We believe that this facility and others like it can be a key to utilities locating "clean" distributed generation in constrained areas and improving grid resiliency.
Dominion announced in late 2012 that it had acquired the project from FuelCell Energy of Danbury, Conn., Which is providing the fuel cells and services. The facility will produce enough to power approximately 15,000 homes using an electrochemical process that converts natural gas into electricity without combustion. Dominion will sell the output to Connecticut Light & Power under a 15-year fixed power purchase agreement. The facility is part of Project 150, a program sponsored by Connecticut and supported by the Clean Energy Finance and Investment Authority to increase renewable and clean energy projects in Connecticut by 150 megawatts.
The power station will have five proprietary stationary fuel cell systems and an organic Rankine turbine that will use waste heat to generate almost 15 megawatts of electricity.
In essence, fuel cells are electrochemical devices that combine fuel - in this case, natural gas - with oxygen from the ambient air to produce electricity and heat, as well as water. The non-combustion process is a direct form of fuel-to energy conversion, and is more efficient than conventional heat engine approaches. Carbon dioxide is reduced because of the fuel cell's high efficiency, and the absence of combustion significantly reduces the production of nitrogen oxides and particulate pollutants.
Fuel cells incorporate an anode and a cathode, with an electrolyte in between, similar to a battery. The material used for the electrolyte and the design of the supporting structure determine the type and performance of the fuel cell. The process uses molten carbonate and porous nickel catalysts as the anode and cathode. At the end of the process, electrons flow through the external circuit, producing the desired electricity in direct current. An inverter changes the DC output to AC for use on the grid.
Distributed generation such as the Bridgeport project has several advantages. Commercial businesses, universities and military bases can become energy self-reliant. It reduces grid congestion and power transmission issues associated with centralized generation. It makes the grid better able to respond to severe weather events and does so with a process that is clean and efficient and available at all times. It is one of the possible keys to recovering from the next disruptive weather challenge that utilities will face.