|The 59 MW Gyeonggi Green Energy Park in Hwasung City, South Korea is the world’s largest
Credit: FuelCell Energy
Tildy Bayar spoke with FuelCell Energy, the company behind it
South Korea is an energy-intensive country with a growing population, high urban population density and little available land. In the wake of a scandal involving falsified nuclear plant safety certificates, the nation aims to reduce its reliance on nuclear power to 29 per cent of its energy mix by 2035.
Due to a lack of domestic resources, imported fuels currently meet around 97 per cent of South Korea’s energy demand. In 2013, the country was the world’s second-largest importer of liquefied natural gas (LNG), the fourth-largest coal importer, and the fifth-largest oil importer.
In a move to clean up its energy mix, South Korea has had a “green growth” policy in place since 2008, with the goal of increasing its use of renewables to 20 per cent of the generation mix by 2027. Among its renewables-friendly policies, the nation has feed-in tariffs (FiTs), a renewable heat obligation and a renewable portfolio standard.
However, its terrain is hilly and thus not particularly well-suited for large solar or wind farms. In the past few years South Korea has shown a growing interest in fuel cell power, with a number of projects in the works.
Enter US-based FuelCell Energy. In February the firm’s South Korean partner, independent power producer Posco Energy, completed the world’s largest fuel cell power plant, the 59 MW Gyeonggi Green Energy park in South Korea’s Hwasung City, which uses FuelCell Energy’s technology. PEi spoke with Tony Leo, FuelCell Energy’s vice president for applications and advanced technology development, and Kurt Goddard, vice president for investor relations, about Gyeonggi, stationary fuel cell power, research and development, market prospects and the firm’s plans for the future.
How a fuel cell power plant works
Fuel cells convert chemical energy from hydrogen-rich fuels into electrical power and heat in a low-emission electrochemical process.
Similar to a battery, a fuel cell is comprised of many individual cells grouped together to form a so-called fuel cell stack. Each cell contains an anode, a cathode and an electrolyte later. When a hydrogen-rich fuel such as natural gas or biogas enters the fuel cell stack, it reacts electrochemically with the ambient air (oxygen), producing electric current, heat and water. But differently from a battery, which has a fixed supply of energy and can be depleted, fuel cells can generate electricity as long as fuel is supplied.
FuelCell Energy’s Direct Fuel Cell power plants are based on carbonate fuel cell technology, in which the electrolyte is made up of potassium and lithium carbonates. Carbonate fuel cells can generate hydrogen from multiple fuel sources in a process called internal reforming, which has been patented by FuelCell Energy. The company says this process offers a competitive edge because it allows readily available fuels to be used. And because there is no fuel combustion, power production emits almost no NOx, SOx or particulate matter, the firm says.
Inside the power plant is the fuel cell stack – or, for multi-megawatt power plants, a module that contains multiple stacks. The incoming fuel is processed by the mechanical balance of plant, while the electrical output is processed by the electrical balance of plant.
At 59 MW, Gyeonggi is quite a bit bigger than the world’s second-largest fuel cell park, a 14.9 MW system in Bridgeport, Connecticut, US, also developed by FuelCell Energy. Posco Energy is also building a third, 19.6 MW fuel cell park in Seoul.
The LNG-fuelled Gyeonggi plant provides continuous baseload power to Hwasung City’s grid. Its 21 Direct Fuel Cell (DFC3000) base units, rated at 2.8 MW each, sit on 2 ha of land. Because of their small footprint, FuelCell Energy’s power plants are easy to site, Goddard said.
“An intermittent solar plant would need about 10 times the land we do,” Leo added. “In South Korea, where there’s high urban population density, we take only five acres in an industrial area for almost 60 MW of continuous baseload power.”
Posco Energy completed the plant in 14 months. “For a project of this size, such a short construction time is a testament to how smoothly it was done,” Leo said, “compared to conventional power plants where it takes that long just to get the permit.”
Permitting for the park was very fast, and Leo explained why: “It’s specific to this technology,” he said, “and it’s the same in California and many other US states. Because fuel cell technology is recognized as emitting virtually no harmful pollutants, we can bypass the air and pollution permitting which is required for a power plant of that size.”
Construction was unproblematic too, Leo said. “Because we’re constructing 21 of the same unit, it’s a relatively straightforward construction process. Instead of 21 separate mobilizations, there are fewer in terms of cranes and such.” Interconnection of the 21 units was “a little more tricky than a single unit”, he said, but didn’t present problems and was “just something we needed to work through in engineering terms.”
The units’ scalability was an advantage, making the project “very different from trying to install one big 59 MW system,” Leo added.
Gyeonggi is “bigger than what we’ve done before, but hopefully will become typical,” he said. “In the grand scheme of power plants, it’s not that big.”
Use of heat
The efficiency of a fuel cell power plant – in Gyeonggi’s case, around 47 per cent electrical – can be enhanced by using the waste heat from the fuel cells in other applications such as industrial processes or facility heating and cooling, although this is “not always possible in systems of this size”, explained Goddard. “In our 14.9 MW project in Connecticut we couldn’t find a user for the excess heat, so we take the waste heat from the fuel cell and make more electricity in a bottoming cycle.”
However, Hwasung City has a district heating system, to which the Gyeonggi plant now contributes 20-30 MW of heat energy. “We recover heat from all 21 units’ exhausts,” said Goddard, explaining that atop each fuel cell power plant’s main equipment section is a waste heat recovery system which transfers heat to a hot water loop and onward to the district heating network. While district heating systems are not common in the US, explained Goddard, “Once you get outside the US and into areas with district heating and cooling, there are interesting options” for excess heat use.
South Korea aims to expand its local manufacturing base, and clean energy manufacturing is predicted to be a driver for the nation’s growth over the next 10 years.
While FuelCell Energy’s components are currently manufactured in Connecticut, Posco Energy, which is a subsidiary of the world’s fourth-largest steel company, is now building a fuel cell component manufacturing facility in Pohang which is expected to begin operation in 2015.
“They’re doing it under license to us,” Goddard explained, “but it’s for them and their marketplace, although we can source components out of that. We initially licensed the balance of plant technology, and a few years ago they started manufacturing heat exchangers and so forth – everything but the fuel cell stack modules. They’re already doing final assembly of fuel cell stacks, and in a couple of years they will be able to manufacture the cells themselves.
“For us this is a royalty stream, but also a second source of supply,” Leo said. “And for some of our customers, the fact that there’s a second source for key fuel cell components is comforting.”
The company is working on improving its technology. “One of those 21 DFC3000 power plants in South Korea generates 2.8 MW, and you have to change the fuel cell stacks every five years,” Goddard said. “We’re developing improvements to the cell technology to increase output to 3 MW and increase the stack life from five to seven years.
“We’ve done this before,” he added. “When we first started selling cells commercially, a DFC3000 would produce 2 MW, then 2.4 MW, then 2.8 MW. It’s been a general evolution and refinement of the carbonate technology.
“We’re also looking at ways to develop new products from carbonate – for example, we’re developing a product that also produces hydrogen in addition to electricity and heat,” commented Leo. The product converts natural gas to hydrogen inside the fuel cell stack, yielding pure hydrogen for use in industrial processes or hydrogen vehicle stations. The company has a demonstration project in California and others in process in Connecticut and Canada.
Another project, supported by the US Department of Energy, involves using fuel cells to capture carbon dioxide. Leo explains: “Carbonate fuel cells have a carbon cycle inside them. If you send CO2 into the air intake, it gets transferred to fuel gas and you can easily separate it out.”
FuelCell Energy is also working on a next generation of fuel cells based on solid oxide technology, “an interesting option for smaller-sized power plants,” Leo says. “Solid oxide is more efficient because of the way electrodes work – but it’s difficult to make the cells very large. A single cell in a carbonate power plant is 9000 cm2 in area – but no one knows how to make solid oxide cells that big; the ones we make now are 600 cm2.
“We’ve scaled up more than anyone,” he said. “We hope to enter the market in a couple of years with sub-megawatt products. And the US government is funding us for solid oxide because they think that, in the long term, it’s good for power plants running on coal gas, and we agree.”
Several other fuel cell companies are active in FuelCell Energy’s target markets. California-based Bloom Energy, which uses solid oxide fuel cells in its 200 kW EnergyServer power plants, has installed systems in Tokyo as well as California and Connecticut. The firm has formed a joint venture with Japan’s Softbank Group to deploy its technology in Japan.
Another US-based competitor, ClearEdge Power, filed for bankruptcy in May. Financial analysts say fuel cell developers face a difficult time in the mid-term, with more bankruptcies and consolidations expected. While investors’ enthusiasm seems undimmed – as recent fundraising such as fuel cell maker Plug Power’s $124 million and Intelligent Energy’s $63 million show – analysts caution against “making bets disproportionate to the long-term revenue opportunities,” as Cosmin Laslau, an analyst with Lux Research, put it.
But Leo is confident about FuelCell Energy’s continuing success. “Ours is the lowest-cost system out there and very high efficiency,” he said. “We’re the most successful fuel cell developer out there.”
Carbonate fuel cell power plants can be used in a variety of scenarios given their fuel flexibility, Leo says. “Quite a few of our units in North America – California in particular – are running on renewable biogas,” he offers, “because carbonate fuel cells aren’t bothered by CO2 dilution of digester gas, for example.
“There is the possibility to take digester gas from a wastewater treatment plant, clean out the sulphur and all of the CO2 and sell it into the natural gas grid – some people do,” he continues. “This is very expensive though, especially the CO2 scrubbing part. We can put a unit right at the customer’s plant so they don’t have to scrub out all the CO2 and it’s less expensive to process the gas.”
A 2.8 MW unit in California is the world’s largest fuel cell power plant operating on renewable biogas, Goddard says. The technology can be useful for food processing companies and breweries as well, he adds, “converting a waste disposal problem into a revenue stream.”
The firm’s future market development is “a wide-open question,” Leo says. “We’re very successful in South Korea, and successful in some North American markets, California in particular. And we’ve opened up, a couple of years ago, a subsidiary in Germany, so we’re starting to address the European market [which] has a lot of potential and hadn’t really been adequately served in the past.”
FuelCell Energy Solutions GmbH is a joint venture between FuelCell Energy and Fraunhofer IKTS. The company operates a facility in Ottobrun which assembles sub-megawatt Direct Fuel Cell power plants.
In the UK, the firm has installed two sub-megawatt systems in central London – including one powering the headquarters of Al Gore’s sustainable investment company – and is working with The Crown Estate on its Regent Street redevelopment project. Leo said the company is “pursuing a variety of megawatt-scale applications all over Europe” and “hopes to announce specifics soon.” Demonstration installations for a federal ministry building in Berlin and a utility customer in Switzerland are “showcasing what the technology can do,” he said.
“We’re now working to scale up into bigger applications – megawatt-class on-site power – and over time we look, hope, expect to have European fuel cell parks like those in South Korea.”
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