The fuel cell-powered microgrid will provide all the power that the “Parkville” community will need during non-emergency operations. If there is an outage, the system will provide emergency power to other locations.
“When the power goes out elsewhere, our state-of-the-art microgrid will keep the power running at a senior center, library branch, school, health center, supermarket and gas station,” said Hartford Mayor Luke Bronin, in a statement. “In addition, the clean energy produced by the fuel cells will result in cost savings for the City of Hartford. That’s a win-win for our city — and we hope to build on this model elsewhere in Hartford.”
The project is a public-private partnership among the City of Harford, Exelon Corp.’s Constellation and Bloom Energy. Constellation is building the microgrid and Bloom is designing the fuel cell. Hartford is buying the output through a 15-year power purchase agreement.
The most practical use of the fuel cell technology is to supply onsite power generation to specific businesses that can’t afford a momentary lapse of electricity. Connecting to a localized microgrid that serves a neighborhood or campus increases the reliability.
The fuel cell and microgrid can be independent of the central grid or they can be set to kick in when the utility-provided power goes out. They are different from distributed generation that directly burn fuels that are used to power whole campuses. Their efficiency rate is 47 percent, say experts, meaning that for each unit of energy that is input, nearly half is returned in the form of power. In combined heat and power applications, where the heat is captured and used, the efficiency rate can jump to 80 percent, they add.
Fuel cells work by separating hydrogen from oxygen. That process requires other fuel sources to break apart the elements. Right now, hydrogen is produced mainly from natural gas using steam reformation, which does nothing to limit the reliance on fossil fuels or the infrastructure that must carry them. The end product, however, is emissions free.
Fuel cells that run on hydrogen have the potential over time to capture market share from stationary power generation. At present, though, those technologies have a small place in the electric power sector and are primarily used by those businesses such as medical complexes, grocery stores and telecommunications firms that need a continuous flow of power.
Bloom Energy has made a big splash with its solid oxide fuel cells that generate around 100 kilowatts and it says that it can convert any fuel source into electricity. Running on a fossil fuel, it says that its systems are approximately 67 percent cleaner than a typical coal-fired plant. Those powered by green energy, meanwhile, are more expensive but can be 100 percent cleaner.
Wall Mart has a goal of becoming fully powered with green energy is one that fits right in. The retailer has installed two “Bloom Boxes” that generate a total of 400 kilowatts at two of its Southern California locations. It says that more such deployments are on the way.
“This moment and time is what existed in the computing and telephony sectors in the 1990s,” says Josh Richman, vice president of global business for Bloom Energy, in a previous talk. Businesses installing such technology can expect to get a return on investment in three to five years, he adds.
To be sure, concerns exist over the conversion route. Experts say that the amount of energy used to make hydrogen is more than the amount of power produced by fuel cells. If fossil fuels are extracted to make the hydrogen, then more pollutants would be released. Green energy, meanwhile, could create the electricity to produce hydrogen but it may not be as predictable or as cost effective.
As fuel cells get incorporated into the marketplace, the technologies will improve and prices will come down. As that happens, both environmental quality and system reliability will also get getter.