Disney, Microsoft, PepsiCo lead business charge on biogas
Despite a few early innovators, the waste-to-energy field still has a long way to go.
The largest U.S. electric holding company, Duke Energy, in March made its first notable commitment to producing power using biogas.
Duke's deal with developer Carbon Cycle Energy could generate up to 125,000 megawatt-hours of energy using methane gas captured from swine and poultry manure sourced in North Carolina. That’s roughly enough electricity to power about 10,000 homes.
"The gas from this project will generate carbon-neutral electricity compared to the emissions that would result if the waste was left to decay naturally," said David Fountain, the Duke Energy executive behind the 15-year-long partnership.
Duke’s motivation isn’t entirely altruistic: It is required to fill up to 12.5 percent of its electricity demand with power generated by alternative sources by 2020. In addition, North Carolina is one of the states mandating that a certain percentage of livestock waste be turned into energy.
The commitment still stands out for its relative rarity among utility companies.
Elsewhere, a number of high-profile companies, including Apple, Disney, Microsoft and PepsiCo, are experimenting with small renewable energy projects fueled by biogas generated through organic waste. General Electric is another vocal advocate — mainly because it provides a line of industrial generators and combined heat and power systems that can operate using this fuel source.
But like most alternative energy propositions, using biogas isn’t simple.
Microsoft’s project in Wyoming, meant to test the viability of a biogas-powered data center, required a $7.6 million investment, partially funded by grants and enabled by partners including the University of Wyoming, the local utility board and another technology company, FuelCell Energy.
The source of the biogas was the Dry Creek wastewater facility. The overall capacity of the project was 200 kilowatts. It was announced back in 2012, and the evaluation period began in November 2014. The verdict? The trail was successful enough to warrant future ones, according to Brian Janous, director of energy strategy at Microsoft.
"We recently completed an 18-month pilot to evaluate if a fuel cell can be run directly on waste gas alone and if a data center can run completely off grid with a fuel cell as the only source of power," Janous said, in response to GreenBiz’s request for an update. "The pilot proved both in the affirmative and we are currently in the process of evaluating a new site for a larger scale waste gas facility."
Gauging the potential
As of last year, the American Biogas Council estimated (PDF) there were about 2,100 U.S. sites producing biogas (but not necessarily using it for power generation).
That’s a pretty small number of the sites that the industry group figures are ripe for development, a number close to 11,000, the group believes. For comparison, more than 10,000 sites in Europe use anaerobic digesters — systems that convert organic waste into biogas that can be used as a substitute for natural gas.
The long and short of the council’s analysis: The capacity in the United States could generate enough electricity for 3.5 million homes.
Yet adoption has stalled for a variety of reasons. Among them: the relatively small-scale capacity of most digester systems; the challenge of sourcing enough feedstock to make them worth the investment; and falling costs for clean power sourced from solar and wind installations.
"Logistical challenges associated with this collection, aggregation, transportation and handling, coupled with poor energy density relative to fossil fuels, make power and fuel generation from biogas viable in only a narrow set of circumstances — where organic matter is available in large quantities, and in continuous supply," noted Navigant Research in a separate 2015 report about this topic.
The project that Disney uses in Orlando, Fla., offers a great illustration of that thesis. The 5.4-megawatt combined heat and power facility uses Harvest Power’s Energy Garden technology. It can process 120,000 tons of organic waste annually, contributed by local restaurants, hotels and food processing organizations. The local Disney World Resort was the facility’s first customer.
Another factor that doubtless will impact the future of biogas projects: state laws governing how large quantities of food waste and other organic materials are managed. Connecticut, Massachusetts, Rhode Island and Vermont have adopted some of the strictest legislation in the United States. Although the exact nature of the laws differs, they all effectively ban co-mingling of food with recyclables and other trash.
That certainly sets the stage for a new crop of anaerobic digester projects, at least in New England, but the landscape remains different state-to-state.
Editor's note: This article originally misstated Wisconsin as the location for Microsoft's project.