Fuel Cells Revisited
The Connecticut Juvenile Training School in Middletown, Conn., for a while this year, boasted the world's large single-site fuel-cell power plant, with six 200-kW fuel cells powering a central plant for 227,000 sq. ft. of space on the campus. Completed in 2001 at a total cost of $49 million, the school hosts approximately 240 boys, sentenced to the facility as a result of convictions in juvenil...
The Connecticut Juvenile Training School in Middletown, Conn., for a while this year, boasted the world’s large single-site fuel-cell power plant, with six 200-kW fuel cells powering a central plant for 227,000 sq. ft. of space on the campus. Completed in 2001 at a total cost of $49 million, the school hosts approximately 240 boys, sentenced to the facility as a result of convictions in juvenile court. According to Lt. Gov. M. Jodi Rell, the seven building facility was a model that the rest of the country would be watching.
While it can no longer claim to be the world’s largest fuel cell installation (see “Talk of the Town”), it has been up and running for more than one year, and it offers a good case study of how a large-scale implementation of this technology can fare.
Connecticut in the Forefront
Why Connecticut? Actually, the state has always been in the forefront of fuel-cell design and implementation. The Clean Energy Fund (CEF), created in 1998 by the Connecticut General Assembly, invests in enterprises responsible for the development of sustainable energy. The fund is administered by Connecticut Innovations, an entity that was created in 1989 by the Legislature and charged with growing the state’s enterpreneurial high-tech economy by making venture and other types of investments.
Another strong driving force behind the state’s enthusiasm for fuel cells is that Connecticut is home to a number of small start-up fuel cell research and technology development companies, as well as three major fuel cell manufacturers: FuelCell Energy of Danbury, Proton Energy Systems of Rocky Hill and UTC Fuel Cells of South Windsor.
In fact, it was the latter—UTC—that provided the six fuel-cell power plants that power the Juvenile Training School. Not only does each unit produce 200 kW of electricity, but also 900,000 BTUs of heat. In addition to providing primary power for the school, fuel cells are used to heat and cool the facility.
UTC, which was then International Fuel Cells, worked with Select Energy, the competitive energy marketing and services subsidiary of Northeast Utilities, and NU affiliate subsidiaries Select-HEC Inc. and Northeast Generation Services Company, on the project for the Connecticut Department of Public Works.
“UTC’s position as the leader in the fuel cell industry, and its power plant’s proven track record made it the logical choice as a partner for this innovative effort to meet our customer’s needs,” said Michael Cassella, Select Energy’s director of new business and large project development.
Powering the Green Revolution
The fuel cells are a central part of the entire power installation that also relies on generators and the electric grid to ensure an extremely high level of reliability. A fuel cell is an electrochemical device that combines hydrogen, or hydrogen-rich fuel, and oxygen to produce electricity, heat and water. Fuel cells operate without combustion, making them almost pollution-free, which is why they are popular for “green building” projects (see “Fuel Cells Power a Green Building,” p.24). While a traditional generating system produces as much as 25 lbs. of pollutants to generate 1,000 kWh of electricity, the type of fuel cell used for the Connecticut Juvenile Training School project power plant uses natural gas as a fuel and produces less than an ounce of pollutants.
The fuel-cell model used for the Juvenile Training School has been manufactured since 1991. Some 220 units have been delivered to customers in 15 countries on four continents. Those power plants have together accumulated some 4 million hours of operation. Use of these power plants has already reduced 600 million pounds of CO2 emissions and 11 million pounds of NO x and SO x compared with typical US combustion-based power plants. The U.S. Environmental Protection Agency recognized the manufacturer last year with a Climate Protection Award as a result of these accomplishments
UTC is the undisputed world leader in fuel cell production at this point in time, as well as in development for commercial, transportation, residential and space applications. For example, the company is the sole supplier of fuel cells for U.S. space missions.
According to Tom Ditoro, P.E., electrical engineer with HDR Engineering, Omaha, the 2002 update to the National Electrical Code, added sections on many new and innovative “green” power systems. Among the technologies now considered in NEC is fuel cells.
“The 2002 NEC defines a fuel cell as an electromechanical system that consumes fuel to produce an electrical current,” says Ditoro. “A phosporic acid fuel cell has a phosphoric acid electrolyte separating its anode and cathode terminals. The electrolyte allows positive hydrogen to pass through, while blocking the electron flow. The hydrogen ions combine with air at the cathode side in an exothermic reaction. This reaction produces heat and water. A load (inverter) is applied across the anode and cathode terminals to allow current flow to occur. The inverter changes the DC current to alternating current—the standard form of power used in electrical current distribution.”
Still in Its Infancy
In many respects, fuel cells represent a technology still in its infancy—a fact that is somewhat confounding, considering that fuel cells have been around for 160 years! William Grove, a judge who pursued science as a hobby, built the first fuel cell in Wales in 1839. However, serious interest in the fuel cell as a practical generator did not begin until the 1960s, when the U.S. space program chose fuel cells to furnish power for the Gemini and Apollo spacecrafts.
Fuel-cell systems are, at present, significantly more expensive than conventional commercial power—$18 million of the total $49 million price tag on the Connecticut Juvenile Training School went to the fuel cell installation—yet prices are expected to decrease to commercially viable levels within the next two to five years. Zero- to low-emissions fuel-cell technology in the United States can potentially reduce air pollution and dependence on imported fossil fuels. Jack Brouwer, associate director of the National Fuel Cell Research Center, states that if new fuel cell technology were to replace all of the current installed capacity of electric generators in the United States, emissions of greenhouse gases could be reduced by about 50% and emissions of nitrogen oxides, sulfur oxides, carbon monoxide, and hydrocarbons could be reduced by about 80% to 90% “The project is consistent with the Connecticut Legislature’s intent to have the state develop diversified energy sources,” says Cassella, “with an ever-increasing percentage of that energy derived from renewable and fuel cell technologies.”
Conditioning is Essential
Power conditioning is another essential link in the school’s power plant. Digital power conditioners, provided by MagneTek, are essential fuel cell subsystems. They convert the direct current (DC) produced by the fuel cells’ electrochemical reaction into precisely controlled alternating current (AC)
Another supplier of power conditioning systems for fuel cells is ABB Power Electronics, New Berlin, Wis., which has provided FuelCell Energy with a total of four units. They recently shipped 1.5-MW and 250-kW units for use with fuel cells from Fuel Energy, and have received an order for an additional 250-kW unit, which features extremely compact inverters and IGBT fast-switching technology.
Fuel cells may still be in their infancy, but the baby is growing fast. With decreasing costs and successful deployment, they are certain to figure increasing in future power systems designs.
From Pure Power, Winter 2002
Talk of the Town
When telecommunications giant Verizon decided to install seven fuel-cell power plants to provide primary power for a critical call-routing center on Long Island, N.Y., it set itself on track to grab the title of largest fuel-cell installation in the world from the Connecticut Juvenile Training School in Middletown, Conn.
The seven units, which each produce 200 kilowatts of electricity and 900,000 BTUs of usable heat, will form the largest fuel cell installation in the world.
Verizon will install the units at a 332,000-sq.-ft. facility that delivers local phone service to some 40,000 customers. The facility houses more than 1,000 employees who handle various functions, including answering customer calls. The fuel cells, which together will generate 1.4 megawatts of electricity, will provide primary electrical power for the facility.
Verizon also plans to install four natural gas-powered generators to operate in parallel with the fuel cells as a hybrid system that can generate up to 4.4 megawatts of electrical power. The generators will serve as backup power, along with the electrical grid and batteries.
Fuel Cells Power a Green Building
Ford Motor Company’s North American Premier Automotive Group, Irvine, Calif., boasts 300,000-sq.-ft. of space that houses the North American headquarters for Aston Martin, Jaguar, Land Rover and Volvo, as well as the global headquarters for Lincoln Mercury.
The facility also claims the distinction of being a “green building,” the first in Orange County and only the third in California to receive Leadership in Energy and Environmental Design (LEED) certification from the U.S. Green Building Council.
Its fuel-cell power plant, which produces 200 kilowatts of electricity and 900,000 BTUs of heat, provides 25% of the building’s power. Additionally, the heat is used to produce hot water for the facility.