ABC, GE Energy discuss community biogas-to-energy

By Anna Simet | June 13, 2012

The technology a developer selects can make or break a biogas project.

That's according to Shonodeep Modak, global market development manager of energy at GE Energy. Modak was one of several speakers of a June 13 webinar jointly hosted by the American Biogas Council and GE Energy, in order to advise how cities and communities can take advantage of waste products through means of biogas-to-energy.

During the webinar, Modak and his fellow presenters emphasized the importance of choosing the right digester and engine for a project, and provided an overview of a planned, cutting-edge Potawatomi Community Digester Project in Milwaukee, Wis.

Modak began the webinar by discussing how GE has quickly grown over the years in respect to the global biogas market.  He said the company acquired Jenbacher in 2003, and at that time only offered 200 kilowatt engines. Since then, the company has added many different products and can now scale up to 9.5 MW.

GE currently employs over 2,000 people and has engines operating in 100 different countries for a broad array of applications, according to Modak. “One day we might be at a hospital for a combined-heat-and-power project, and the next day at a wastewater treatment plant or an on-farm digester project,” he said.

Modak said GE views its engines as a project's financial engine. “We're constantly looking at how your internal rate of return can be improved, capital costs or project pay back.”

But there are many things that influence those factors, he pointed out, including feedstock size, technology selection power price, carbon price financial structure and digester selection. “[Digester selection] is just important as the biogas engine,” Modak added.  “[For biogas engines] there are lots of technologies out there, but you want to be able to make the most electrons possible.”

For GE engines, every 3 percent efficiency is worth 1-2 percent internal rate of return, he said.

Following Modak, Bryan Johnson, GE renewable/sustainability team leader, discussed a 2 MW biogas project the company is helping implement for the Potawatoni Community in Milwaukee, Wisc. He said the community investigated what the best technology was to utilize organic waste—which the area is known for— and the most feasible and cost-effective solution turned out to be biogas.

The facility will be located on a 3-acre, former brownfield site that was previously tamarack swampland. Utilizing a 10,000-square foot building, the digester system will consist two tanks, 90 feet in diameter and 50 feet tall, and will take in a diverse range of locally available, pumpable organic feedstocks. GE will supply two Waukesha APG1000 engines.

Johnson said one characteristic of the project that was particularly important to the community was that the facility was aesthetically pleasing, so a lot of work went into the physical design.

Construction of the project would begin later this year, he added, and it should be complete in 2013.

For a full recording of the webinar with additional presenters, visit