Fuel Cells: What They Are, How They Work, and Why They’re Important
Fuel cells are not some novel new technology. In fact, most history books credit the invention of the fuel cell to Welsh chemist and physicist William Grove, who, in the late 1830s and early 1840s, conducted experiments proving that electric current could be produced from an electrochemical reaction between hydrogen and oxygen over a platinum catalyst.
Yet, fuel cells never really took off as a mainstream source of power. Why is that? “I think the real reason is, historically, we’ve been comfortable with less-clean, lower-efficient but less-expensive technologies, because we haven’t been as focused on air quality and on decarbonization as we currently are,” Tony Leo, executive vice president and Chief Technology Officer with FuelCell Energy, said as a guest on The POWER Podcast.
However, as people have become more focused on air quality and climate change, Leo suggested fuel cells are now poised to take off. “That’s why you’re seeing such an acceleration in the deployment of fuel cells and that’s why you’re hearing more and more about them these days,” he said.
How a Fuel Cell Works
A fuel cell is a device that makes electricity from fuel and air. Instead of burning the fuel to make heat to drive a mechanical generator, fuel cells react the fuel and air electrochemically, without combustion. The electrochemical approach avoids pollutants that are created by high flame temperatures, and it is a more direct and efficient way to make power from a fuel.
Reacting fuel and air electrochemically involves delivering fuel to a set of negative electrodes (called anodes) and delivering air to a set of positive electrodes (called cathodes). The electrochemical reaction of fuel produces electrons. The electrochemical reaction of oxygen in air consumes electrons. Connecting the two produces the current of usable electrical power.
Fuel cells are configured in stacks of individual cells connected in a series. FuelCell Energy’s carbonate stacks have up to 400 cells per stack and produce between 250 kW and 400 kW of power. FuelCell Energy’s standard MW-scale module contains four stacks, nets about 1.4 MW of power, and can make electricity for sites such as universities, hospitals, and data centers. The modular design of fuel cell plants allows them to scale up to a specific site’s energy needs.
Benefits of Fuel Cells
“One big advantage is they’re quiet,” said Leo. “Since they don’t have a big spinning machine and this big spinning generator, they’re quiet compared to traditional power generation, so you can site them in population centers. We have a 15-MW fuel cell right in the middle of downtown Bridgeport, Connecticut, for example, and that just makes a really good neighbor.” The lack of harmful emissions is also a benefit.
Another advantage is that while fuel cells are making electricity, they’re also making heat that can be used to produce hot water or steam, or to drive chilling operations. “That further enhances the sustainability because you get to avoid burning fuel in a boiler, for example, if you can use the heat coming off the fuel cell,” said Leo.
Additionally, fuel cells don’t require a lot of maintenance or a large operations staff. “They’re unmanned—we monitor them remotely—and so, they take care of themselves and just generate value,” Leo explained.
Large and Innovative Projects Around the World
Just outside Seoul, South Korea, there’s a fuel cell park that produces 59 MW of power. “We originally manufactured that system for a distribution partner that we had—POSCO. We have just now taken over the service agreement for that project, so we’ll be making stacks to keep that project going for many years to come,” said Leo. “That’s the biggest project in the world—that’s also producing heat in addition to power that goes into a district heating system.”
Another interesting project began operation in Southern California recently. FuelCell Energy and Toyota Motor North America Inc. celebrated the grand opening of the first-of-its-kind “Tri-gen” system at the Port of Long Beach on May 2. Tri-gen uses biogas to produce renewable electricity, renewable hydrogen, and usable water. It was built to support the vehicle processing and distribution center for Toyota Logistics Services (TLS) at Long Beach (Figure 1), Toyota’s largest North American vehicle processing facility, which receives approximately 200,000 new Toyota and Lexus vehicles annually.
“We have a system that in addition to producing electricity, also produces hydrogen that they use to fuel those vehicles and it also produces water they use to wash cars,” Leo explained. “So, that’s an example of a new application of fuel cell technology that’s very different.” TLS Long Beach is Toyota’s first port vehicle processing facility powered by 100% onsite generated renewable electricity.
Scale-Up Could Bring Costs Down
What Leo said is currently holding fuel cells back is the cost. “Fuel cell technology tends to be more expensive at this point than the incumbent legacy technologies, just because they’re new and because they haven’t yet achieved the volume that these legacy technologies have,” he said. “I think that will change over time as there’s more and more deployment, and that deployment is now being driven by decarbonization.”
Meanwhile, there are some government incentives available too. “Some of them are very similar to the wind and solar [incentives],” Leo said. “For example, there’s a federal investment tax credit, where a person installing a fuel cell can take a percentage of the capital costs and apply that as a tax credit.”
In California, there are additional incentives around the state’s Low Carbon Fuel Standard. There are also capital cost incentives in Connecticut, where a renewable energy credit mechanism supports fuel cells. “That’s what makes our Bridgeport 15-MW system economical, for example,” said Leo. He noted there’s a similar mechanism in South Korea.
Leo, a 40-year veteran of the fuel cell industry, has seen his share of ups and downs over the years, but he remains very optimistic about the future. “I feel really strongly that we are, in fact, globally and as a nation, one way or the other, going to go through an energy transition to decarbonize the grid and to clean up the air,” he said. “As the demand goes up for onsite power generation in areas like data centers, we think that people are going to look to a more sustainable way to meet that need, and we think that’s an opportunity for us.”
To hear the full interview with Leo, which contains more about the benefits of fuel cells, carbon capture technology, hydrogen, FuelCell Energy’s competition, distributed energy systems, the company’s manufacturing facilities, and much more, listen to The POWER Podcast. Click on the SoundCloud player below to listen in your browser now or use the following links to reach the show page on your favorite podcast platform:
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—Aaron Larson is POWER’s executive editor (@AaronL_Power, @POWERmagazine).