The Dry Creek Water Reclamation Facility has an unusual new neighbor.

A $112 million Microsoft modular data plant, almost the size of a shipping container, houses 200 computer servers next to the plant in Cheyenne, Wyoming. It gets its electricity from a fuel cell powered by the Dry Creek plant’s biogas in a system that produces carbon-free electricity to benefit both facilities.

The $7.6 million biogas demonstration project was funded by Microsoft with the help of $1.5 million in assistance from the Wyoming Loan and Investment Board. The data plant will use about two-thirds of the power from the 250 kW fuel cell. The rest goes to Dry Creek, along with 200,000 Btu/hr of heat for the plant’s anaerobic digesters.

“It’s all technology that exists,” says Randy Bruns, CEO of Cheyenne LEADS, the economic development group for the city and Laramie County that coordinated the deal. The difference is that the technologies have never been combined in such a decentralized approach. Local officials believe the Cheyenne installation to be the world’s first waste-to-energy data center.

Concept testing

Microsoft already has a large data center and operations facility in a business park owned by Cheyenne LEADS and is adding a $274 million expansion to meet growing demand as people and businesses store data and programs on cloud-based services.

Such centralized data centers require large amounts of electric and fiber optic capacity that isn’t available in all areas. Smaller, decentralized data plants provide more flexibility in location, and that is the concept being tested in the 18-month demonstration project in Cheyenne.

“Everybody needs to see how the economics work out before deciding the next step,” says Bruns. “There continues to be a lot of interest, even by some players not involved at the moment. But all of that is to be determined.” Microsoft says it intends to eventually donate all the infrastructure to the participants in the project.

Clint Bassett, water conservation specialist for Cheyenne’s Board of Public Utilities, says Dry Creek will make decisions about the future of the biogas system after the demonstration project is complete. Dry Creek is the larger of the city’s two water reclamation facilities and provides the solids treatment for both. The plants provide about 200 million gallons a year for irrigation of more than 230 acres of public land through a 12-mile distribution system.

The modular data plant went online in November 2014 after operating on natural gas for about six months. The servers are used by the University of Wyoming, another partner in the project. Other participants are the Cheyenne Board of Public Utilities, Cheyenne Light, Fuel and Power Company, Western Research Institute, the Wyoming Business Council, Siemens, and FuelCell Energy Inc.

Going renewable

With a goal of creating carbon-neutral data centers, Microsoft approached FuelCell Energy in 2012. “The idea of powering a data center with completely renewable biogas from a wastewater treatment plant really excited them,” says Anthony Leo, FuelCell Energy vice president of applications and advanced technology.

The project uses FuelCell Energy’s DFC 300 self-contained combined heat and power (CHP) system. The company also has larger systems of 1.4 MW and 2.8 MW. “The treatment plant was making biogas but wasn’t using it,” says Leo. “We had to connect to that biogas supply, install a gas cleanup system, and put in a system to get the waste heat from fuel cells back into the digesters.”

The small unit at Dry Creek requires only 60 cfm of biogas. With low or zero emissions, fuel cells are just as environmentally friendly as renewables such as wind and solar, but generate electricity continuously. Compared to power from the grid in Wyoming, the Dry Creek fuel cell project reduces annual emissions by 3.5 tons of NOx (smog), 3.5 tons of SOx (acid rain) and 2,910 tons of CO2 (carbon dioxide, a greenhouse gas).

A power monitoring system (Siemens) controls power dispatch to the data plant and the treatment plant while tracking biogas volumes, electrical generation and output. The fuel cell is connected directly to the data plant and to the electrical grid.

“The power quality from the fuel cell is inherently very good,” says Leo. “We’ve been testing the way the fuel cell provides power to the data center when it is connected to the grid, when it’s disconnected from the grid, and when the data center is ran at different levels of use.”

Pulling it together

Before construction could begin, it took about a year to develop a contract between all the agencies. That’s where Cheyenne LEADS made a difference. “It’s not what wastewater treatment plant managers do, it’s not what data center operators do,” says Bruns. “It was outside everybody’s specific field, yet they all had to play together. One of our roles is to be a connector of dots, a clearinghouse of information, and to get the right people talking to one another.”

That will be necessary again as decisions are made about the future. “Whether this continues to power a data center or something else, our hope is that what we’ve learned makes it easier for more biogas to be used in a meaningful way,” says Bruns. “Demands are going to change, resources are going to change. We have to think openly about that, not limit ourselves. As cool as all this is at a technical level, the most powerful part of the project, in my mind, is the people it has brought together and the willingness to explore other ideas.”

He sees potential beyond how to use biogas, such as finding ways to deploy decentralized generation and use the power on site, as at Dry Creek, rather than transmitting it over wires. “Once you start down that path, it would seem that there are thousands of opportunities,” says Bruns. “The real power of this is having people from all these different disciplines working together and thinking about other solutions.