Fuel cell power plant
Power station that uses fuel cells to generate electricity
From Wikipedia, the free encyclopedia
A fuel cell power plant is a power station or distributed generation system that uses fuel cells to generate electricity. Unlike a conventional thermal power plant, which generates electricity by burning fuel to produce mechanical work, a fuel cell converts chemical energy into electricity through an electrochemical reaction. Fuel cell power plants may be connected to the electrical grid, used as on-site power systems, or configured for combined heat and power.
Fuel cell power plants can operate on different fuels, including hydrogen, natural gas, biogas, methanol, and hydrogen-rich fuels produced from other sources. The most common stationary power technologies include phosphoric acid fuel cells, molten carbonate fuel cells, solid oxide fuel cells, and proton-exchange membrane fuel cells.[1][2]
Technology
A fuel cell power plant is usually made up of multiple fuel cell stacks, fuel supply equipment, air supply equipment, cooling systems, power electronics, controls, and sometimes heat-recovery equipment. Fuel and oxygen are supplied continuously to the fuel cell, allowing the plant to generate electricity as long as fuel is available. Direct-current electricity from the fuel cell stacks is converted to alternating current for grid or facility use by an inverter.
Stationary fuel cell systems are generally modular, so larger plants can be built by combining multiple fuel cell units. Smaller systems may supply a single building, while larger installations can provide power to campuses, industrial sites, utilities, or data centers. Depending on the design, a fuel cell power plant may operate as base load generation, backup power, a microgrid resource, or a combined heat and power system.[3][4]
Types
Fuel cell power plants can be classified by fuel, by fuel cell chemistry, or by use. High-temperature fuel cells such as molten carbonate fuel cells and solid oxide fuel cells are often used for stationary power because they can operate on natural gas, biogas, or other hydrogen-rich fuels. Phosphoric acid fuel cells have also been used in stationary combined heat and power systems. Proton-exchange membrane fuel cells are commonly associated with hydrogen applications and can respond quickly to changes in power demand.
| Type[5] | Common stationary-power use | Typical fuel |
|---|---|---|
| Proton-exchange membrane fuel cell | Backup power, hydrogen power systems, grid support | Hydrogen |
| Phosphoric acid fuel cell | Building-scale and campus combined heat and power | Hydrogen or reformed hydrocarbon fuel |
| Molten carbonate fuel cell | Utility-scale and industrial stationary power | Natural gas, biogas, syngas, or hydrogen-rich fuel |
| Solid oxide fuel cell | Distributed generation, industrial power, and data center power | Natural gas, biogas, hydrogen, or syngas |
| Direct methanol fuel cell | Small stationary or portable power | Methanol |
Natural gas and biogas fuel cell power plants
Natural gas fuel cell power plants are designed to operate on natural gas, biogas, landfill gas, or other methane-rich fuels. They commonly use high-temperature fuel cells such as molten carbonate fuel cells and solid oxide fuel cells. In these systems, methane and other light hydrocarbons can be converted into usable fuel within the fuel cell system, reducing or eliminating the need for externally supplied hydrogen.
Natural gas fuel cell power plants are not zero-emission when operated on fossil natural gas, because carbon in the fuel is converted to carbon dioxide. However, because electricity is produced electrochemically rather than by combustion inside the fuel cell stack, local emissions of nitrogen oxides, sulfur oxides, and particulate matter are generally much lower than from combustion-based generators. Fuel cleanup may be needed to remove sulfur compounds or other contaminants that can damage fuel cell components.[6]
Hydrogen fuel cell power plants
Hydrogen fuel cell power plants use hydrogen as the supplied fuel. When pure hydrogen is used in the fuel cell, the direct products are electricity, heat, and water. The overall environmental impact depends on how the hydrogen is produced, stored, and transported. Hydrogen produced from electrolysis of water using low-carbon electricity can have lower lifecycle emissions than hydrogen produced from fossil fuels, while hydrogen produced from natural gas reforming can still be associated with carbon dioxide emissions.
Hydrogen fuel cell power plants may use proton-exchange membrane fuel cells, phosphoric acid fuel cells, or solid oxide fuel cells. They can be used for grid power, backup power, microgrids, and combined heat and power. Because hydrogen can also be produced from surplus electricity, hydrogen fuel cell power plants are sometimes discussed as part of long-duration energy storage systems.[7][8]
Other fuels
Some fuel cell systems can use fuels other than hydrogen or natural gas. Direct methanol fuel cells use methanol directly, although they are more commonly used for portable or small stationary applications than for large grid-connected power plants. Other fuel cell systems may use ethanol, propane, ammonia, or syngas after the fuel has been converted into hydrogen-rich gas. Fuel flexibility is one reason high-temperature fuel cells are considered for stationary power applications, but the practical fuel choice depends on cost, fuel availability, emissions rules, fuel cleanup requirements, and the fuel cell chemistry used.[9]
Combined heat and power
Fuel cell power plants can be configured for combined heat and power by recovering heat from the fuel cell system for hot water, steam, space heating, industrial processes, or district heating. Heat recovery can increase total fuel-use efficiency compared with producing electricity and useful heat separately. This is especially useful for buildings or industrial sites with steady thermal loads, such as hospitals, universities, hotels, food-processing facilities, wastewater-treatment plants, and district energy systems.[10]
Applications
Fuel cell power plants are used for utility generation, distributed generation, microgrids, combined heat and power, and on-site power for large electricity users. They are used at hospitals, universities, municipal facilities, industrial sites, wastewater treatment plants, military facilities, and data centers. Compared with many combustion-based generators, fuel cell systems can be quieter and more compact, but siting can still raise concerns about land use, gas infrastructure, emissions, and the concentration of energy facilities in particular neighborhoods.[11]
Examples
The Gyeonggi Green Energy fuel cell park in Hwaseong, South Korea, began commercial operation in 2014 with a capacity of about 59 megawatts. The plant uses fuel cells supplied by FuelCell Energy, runs on natural gas converted within the fuel-cell system, and supplies heat to a local district heating system.[12]
The Shinincheon Bitdream Fuel Cell Power Plant in Incheon, South Korea, entered service in 2021 with a capacity of 78.96 megawatts.[13]
In the United States, the Bridgeport Fuel Cell Park in Bridgeport, Connecticut, is a 14.9 megawatt fuel cell project on a former brownfield site. Fuel cell systems have also been deployed for data center power, including a Bloom Energy and Equinix deployment that exceeded 100 megawatts of capacity across multiple U.S. data centers.[14][15]
Advantages and limitations
Fuel cell power plants can provide efficient, modular, and relatively quiet electricity generation with lower local air pollution than many combustion-based generators. They can also be paired with heat recovery, renewable fuels, or carbon capture depending on the system design. Limitations include high capital cost, fuel cell stack degradation, fuel cleanup requirements, dependence on fuel supply infrastructure, carbon dioxide emissions when fossil fuels are used, and slower startup times for some high-temperature systems compared with conventional backup generators.[16]
Air filtration
Fuel cell power plants require a continuous supply of intake air for the electrochemical reaction, and this air may be filtered before entering the fuel cell system. Some large fuel cell plants have been described as removing fine dust from intake air during operation, the Shinincheon Bitdream Fuel Cell Power Plant in South Korea was reported to remove about 2.4 tons of fine dust annually.[17]