You might say that at GE, when the you-know-what hits the (digester) fan, we like it! While farmers have long valued manure as a fertilizer, at GE Energy it’s also a source of power — biogas — that can fuel the company’s highly efficient Jenbacher engines. That technology in action was in the spotlight last week as more than 80,000 visitors over three days descended upon the 2009 Dodge County Farm Technology Days in Waterloo, Wis. The big event was held at the Craves Brother Farm, which is a cheese factory, dairy farm — and a biogas energy plant that uses GE’s Jenbacher to run the farm and send power back to the local grid. In videos shot by GE’s Don Spieth, the Craves explain the process, including how even the leftovers still have valuable use as a fertilizer. (Make sure you aren’t eating when you watch that one!)


Say, cheese! As the Wisconsin State Journal reported: “One of the biggest draws to the show was a $4 million manure digester, owned by Clear Horizons, a Milwaukee company that develops biogas energy systems. An estimated 5,000 people toured the digester operation, which makes electricity from the waste of the Crave Brothers’ 2,000 cows,” the paper reported.

The ecomagination-certified Jenbacher J312 biogas engine, which was installed in May, is now generating 633 kilowatts of electricity — which can power the farm, the factory and over 300 homes. Crave Brothers originally had operated an older, less powerful biogas system to support some of the farm’s electricity requirements, but switched to GE’s Jenbacher to generate even more electricity.

In the video below, Charlie Crave talks about the “food, fuel and future” theme of the event that ties together their cheese-making, the biogas system, and the whole sustainability idea behind it. But the bottom line is that it’s still a business. As Charlie says: “When it all comes together, it has to pay. So the economic viability, the environmental viability, and the social responsibility are core values of our family.”


Widely accepted in Europe, the use of biogas digester systems with GE’s Jenbacher engines is a fairly new U.S. agri-business trend. In the past, some U.S. farmers had used old diesel motors and smaller gas engines until they began installing more durable, robust gas engines in recent years. To get a sense of how much “you-know-what” it takes, if you had 2,500 cows, 15,000 pigs or 300,000 chickens you can create enough biogas to power 900 homes in the European Union using just one of GE’s Jenbacher engines.

In the video below, Karl Crave, who is Charlie’s son, gives a brief look at GE’s Jenbacher.


Renewable energy developer Clear Horizons, which built and owns the digester biogas plant at the Crave Brothers site, is supplying the engine’s electricity to the regional grid operator.


Way more than knee-deep! The giant digester is where the manure goes to be processed. This photo, shot during construction, shows just how massive the processer is compared to the person standing in the center.

In the process, the manure is circulated and anaerobic, or oxygen-free, digestion takes place. Microorganisms break down the organic waste, ultimately producing gas — mainly methane with some carbon dioxide. This gas can be burned just like natural gas, thus generating energy.


It literally does hit a fan: The tall fan is an axial stirrer. The short blade is a mixer. (Fortunately, these photos were taken before they were ever used.)

Dan Nemke, the general manager of Clear Horizons, explains how the digester works. (The plant noise may be loud, but Dan does a great job simplifying a complicated process).


Of great relief to everyone involved — especially neighbors who live near large farms — is that the digester reduces odor from the manure when the liquefied portion is ultimately spread on fields. And the dry, solid byproducts are used as animal bedding and in a line of organic potting soil.

In the video below, Karl Crave explains how the end product, after the biogas is removed, is used.


* Watch an NBC News video about the Crave Brothers Farm
* Read GE’s announcement about the Wisconsin Jenbacher
* Read about the Wisconsin facility in trade publication PennEnergy
* Read about Jenbachers powering greenhouses
* Read “The Sweet Smell of Success” about Jenbachers and landfill gas
* Learn how many cows, pigs or sheep it takes to power 900 homes
* Learn about waste-heat recovery
* Learn more about ecomagination
* Read about biogas technology
* Learn more about Jenbachers
* Watch a Jenbacher video