When deciding how to meet the power and thermal energy needs of commercial and industrial facilities, executives must consider a range of priorities including cost, safety, reliability, and environmental stewardship. While on-site power and heat generation is often considered because of the potential for enhanced reliability and energy savings, typical equipment for on-site generation can also mean increased emissions, noise, and high operating expenses.
In recent years, a compelling on-site power and heat alternative is being adopted which is ultra-clean, affordable and highly efficient fuel cell power plants. These leading-edge systems generate virtually-pollutant free electricity and heat via an electrochemical process, without combustion, where the power is used. They economically address facility management priorities while supporting sustainability initiatives and providing key societal benefits of clean air and low carbon emissions.
Many people associate fuel cells with the space program or vehicles which require pure hydrogen as a fuel source; However, some fuel cell systems use readily available natural gas or renewable biogas as fuel. It is these systems that are being commercially deployed in stationary applications globally.
Fuel cells are unique as they extract energy from fuel without burning. Instead, fuel cells react fuel with air electrochemically, similar to reactions that consume zinc or cadmium in common batteries. In a battery, however, the reactants are used up or recharged; fuel cell reactants get fed continuously into the fuel cell, making power as long as fuel and air are supplied. The electrochemical conversion process has several advantages over combustion. Since there is no flame, the harmful pollutants created by burning fuel, such are nitrogen oxides (NOX) or particulates are simply not produced. Also, fuel cells create electricity directly from the fuel, at higher efficiencies than mechanical systems with multiple energy conversion steps. By eliminating moving parts, fuel cells are inherently quiet, a key aspect for urban locations.
At the heart of a fuel cell power system are the “stacks” of individual fuel cells, where the electrochemical reaction of fuel and air occurs. Fuel cell stacks consist of hundreds of alternating negative and positive electrodes, similar to the electrodes in batteries. Fuel flows over the negative electrodes and air flows over the positive electrodes. As fuel flows over the fuel electrodes a reaction occurs that produces electrons. A complimentary reaction occurs with air at the air electrodes to consume electrons, producing an electrical current.
For commercial or industrial scale stationary power generation, power plants need a readily available fuel, such as natural gas or renewable biogas from wastewater treatment. The primary energy component in these fuels is methane, which can be converted to hydrogen by reacting with water in a process called reforming.
Fuel cell technologies are characterized by the electrolyte used to separate the fuel and air electrodes, and several types are currently commercially available for use in on-site combined heat and power (CHP) applications. One of these, called the carbonate fuel cell, offers a number of distinct advantages. Carbonate fuel cells operate at high temperatures, which promotes very high electrical efficiency, and avoids the need for rare, expensive, catalysts like platinum that are needed for lower temperature fuel cells.
In a CHP configuration the heat is supplied to facilities and hot water systems, absorption chilling systems for facility cooling, or even sold to neighboring facilities. When used for CHP, carbonate fuel cells can approach 90 percent total thermal efficiency if there are sufficient on-site needs for heat.
Carbonate fuel cell power plant installations are operating at more than 50 sites on three continents. The California State University East Bay installation (pictured) is a typical of on-site combined heat and power system supplying the campus with ultra-clean and reliable on-site power and heat.
Installing multiple fuel cell plants together to provide power to the electric grid is a growing market. Utilities can add continuous ultra-clean power where it is needed, avoiding transmission and not being dependent on weather or time of day. The world’s largest fuel cell park is in South Korea, consisting of 21 fuel cell plants generating 59 megawatts of power for the electric grid plus high quality heat for a district heating system. Growing adoption is further reducing the overall cost of these solutions, which makes the technology even more attractive for facilities and utilities want or need more reliable and environmentally responsible on-site power and heat production, delivered affordably.
Tony Leo serves as Vice President, Applications and OEM Engineering at FuelCell Energy. Mr. Leo joined FuelCell Energy (then named Energy Research Corporation) in 1978 to work on advanced electrochemical technologies for energy storage and generation. He is now overseeing another department in FCE, focused on Application Engineering and Original Equipment Manufacturer (OEM) support. He has held numerous positions in FuelCell Energy involved in managing advanced research and development of rechargeable batteries and fuel cells. When FCE began to commercialize the DFC technology, Mr. Leo managed the first large-scale demonstration of the technology in Santa Clara, California. He also established FCE’s first Product Engineering group, and directed the transition of it from reliance on outside engineering contractors to the development of a fully capable engineering department. In addition, Mr. Leo managed the creation of FCE’s Service and Project Management organizations during its evolution from an R&D organization to a product company. He serves as a Director of Versa Power Systems, Inc. He is well known throughout the battery and fuel cell industry, has authored numerous papers, contributed to technical books, and been awarded two US Patents. Mr. Leo holds a BS in Chemical Engineering from Rensselaer Polytechnic Institute.
