Fuel cells find new applications
A fuel cell creates electricity from hydrogen, or hydrogen-rich fuel, and oxygen. If pure hydrogen is used, fuel cells emit only electricity, heat, and water. Fuel cells can be used in a wide range of applications including transportation, stationary, portable, and backup power applications.
A fuel cell consists of two electrodes—a negative electrode (or anode) and a positive electrode (or cathode)—sandwiched around an electrolyte. A fuel, such as hydrogen, is fed to the anode, and air is fed to the cathode. If a hydrogen source is not available, a fuel processor converts natural gas to hydrogen. In a hydrogen fuel cell, a catalyst at the anode separates hydrogen molecules into protons and electrons, which take different paths to the cathode. The electrons go through an external circuit, creating a flow of electricity. The protons migrate through the electrolyte to the cathode, where they unite with oxygen and the electrons to produce water and heat.
Fuel cells have come a long way since they were used only to power spacecraft. However, the promise of fuel-cell-powered cars fueled by hydrogen seems to be running on empty.
Whereas the use of fuel cells in the transportation sector has fallen short of what was expected a decade ago, things are different in the power sector. Fuel cells represent a tiny, but growing, share of total generation with the largest fuel-cell power plants approaching 40 MW. The primary difference between the transportation and power sectors is fuel. Instead of using hydrogen as do fuel cells for vehicles, power sector fuel cells use natural gas.
Kurt Goddard, Vice President, Investor Relations for FuelCell Energy sees growth in the fuel cell industry: “The size of the applications continues to increase, the adoption by leading utilities and global companies is advancing, the awareness and appreciation of the attributes of fuel cells continues to expand globally, and the types of applications continues to grow,” he said.
Fuel cells support utility grids
Grid support applications, where power is supplied to electrical grid or utility substations, provide utilities with an economical, practical, and scalable way to enhance grid resiliency. An example of a grid support application is the 14.9 MW installation for Dominion Energy in Bridgeport, Connecticut. Comprised of five SureSource 3000 plants from FuelCell Energy, each of which generates 2.8 MW, this fuel cell park is utility-owned and located on a remediated brownfield property occupying only 1.5 acres. The project enhances the resiliency of the electrical grid by generating predictable and clean power for three substations. “The city benefits by returning an unused and difficult to develop brownfield back to the property tax rolls as well as benefitting from infrastructure enhancements and environmental remediation of the city-owned land that was paid for by the project,” said Goddard.
In another grid support application, Delmarva Power in Newark, Delaware has deployed 30 MW—enough to power about 22,000 homes—generated by fuel cells from Bloom Energy. “The project provides price stability and predictability over the term of the project,” said Asim Hussain, Vice President of Marketing and Customer Experience at Bloom Energy. “It also provides environmental benefits far superior to conventional electricity generation.”
Fuel cells stabilize on-site power
While utility applications for fuel cells are growing, so are onsite or “behind-the-meter” applications, where power is generated at the point of use, providing end users with improved power reliability and energy security by reducing reliance on the electrical grid.
At Pfizer’s research and development headquarters in Groton, Connecticut, two FuelCell Energy SureSource 3000 plants generate 5.6 MW of power to increase the energy resiliency of the 160-acre campus. The on-site fuel cell plant ensures continual power even in the event of a grid disturbance. This aspect of predictable power is critical to avoid disruption of pharmaceutical research and testing.
The Owens Corning Roofing and Asphalt Plant in Compton, California was dealing with several power outages per week due to an overloaded local infrastructure. To mitigate this issue, the company installed two 200 kW fuel cells from Bloom Energy to provide approximately 65% of the plant’s power.
The Coca-Cola Bottling plant in Elmsford, New York installed a pair of PureCell Model 400 fuel cells from Doosan Fuel Cell America Inc. to deliver reliable power, reduce water consumption, and benefit the environment. At the Elmsford plant, the third largest Coca-Cola bottler in the world, the two units have been providing 35% of the electricity and heat required to operate the facility since 2010. The units are capable of operating independent of the local electric utility, so if there’s a power outage, the fuel cells will continue to provide power to the facility until grid power is restored. The Doosan on-site power plants provide continuous power for electrical needs, heat for process loads and space heating, and grid-independent backup power.
Using heat from fuel cells
Combined heat and power (CHP) is the useful application of byproduct heat from on-site electrical generation. CHP is an important strategy for reducing greenhouse gas (GHG) emissions. “For industrial applications, fuel cell plants are typically configured for CHP so end users benefit from a continuous and predictable supply of clean electricity and the high-quality heat, steam, or hot water to support processes and facility needs,” Goddard said.
St. Helena Hospital, a 181-bed full service community hospital in Napa Valley, California, installed a Doosan fuel cell to provide clean, reliable energy to the 350,000 sq ft facility. In addition to providing 63% of the hospital’s electricity needs, the fuel cell also provides 50% of the facility’s space heating and hot water requirements through on-site distributed generation.
The Pepperidge Farm bakery in Bloomfield, Connecticut has two SureSource power plants configured for CHP. The fuel cells meet the majority of the plant’s power needs along with a solar array that supports peak power needs. The high temperature heat generated by the fuel cells is supplied to the facility to support the baking process. The CHP configuration enhances efficiency while reducing CO2 emissions and pollutants by lessening Pepperidge Farm’s reliance on a combustion-based boiler.
Fuel cells generate clean power
Not only do fuel cells produce electricity, heat, and water, they do it cleanly and efficiently. Fuel cells do not operate using combustion. Therefore, they are virtually pollution free. Because the fuel is converted directly to electricity and heat, the total system efficiency of fuel cells can be much higher than internal combustion engines, extracting more energy from the same amount of fuel.
“The main issue is being able to produce energy that costs less than the grid,” said David Giordano, Federal and State Government Relations at Doosan. “Other issues deal with the fact that [fuel cells] are the cleanest way to use natural gas; [they] can provide power to critical facilities when the grid goes down because [they] run 24/7—and they lower greenhouse gas (GHG) emissions and criteria air pollutants.”
In September of 2013, eBay Inc. opened its data center in Salt Lake City—the first in the world to use Bloom Energy fuel cells as primary, on-site power. The state-of-the-art facility incorporates 30 Bloom Energy Servers, providing 6 MW of power into the mission critical data center’s energy architecture. The electric utility grid will be used only as backup. By using Bloom Energy fuel cells—which generate on-site power 24 hours a day, 365 days a year—eBay replaced large expensive backup generators and UPS components, and will drastically reduce the carbon footprint of its new facility.
Fuel cells provide grid support for utilities, and on-site power stabilization and process heat for end users. To decide if a fuel cell is appropriate for your operation, you should understand your power usage and costs. Is high electrical efficiency or high thermal efficiency of value? Is an environmentally “green” power source important to you? Can you make use of the heat byproduct for your facility? If so, a fuel cell can be the right choice.