Heating Homes With Manure: In Germany, Villages Begin Producing own Power
A handful of villages in Germany are already securing their heating needs by means of bio-energy. Now more boroughs want to set up their own grids of self-produced energy.
Ralf Keller, an organic farmer, had a waste problem. The quantity of heat energy escaping his biogas plant every year was equal to that contained in 180,000 liters (47,550 gallons) of heating oil, he calculated.
Every day, the facility on his farm in Mauenheim, in southern Germany's Baden region, ferments 10 tons of corn, 1 ton of grass and 4 tons of dung to produce methane. Keller uses the methane to produce 2 million kilowatt-hours of electricity a year. And like it or not, the process releases considerable amounts of wasted heat.
Keller decided to just give the heat away. But that wasn't easy in his idyllic village, which has only about 100 households. Who here needs that much heat? Even if it's free?
As it happens, Mauenheim is not too far away from Singen, in southern Germany, and Singen is the seat of Solarcomplex, a small but creative eco-company owned by 200 shareholders, most of whom come from the region around Lake Constance. When Solarcomplex learned about the offer, the company was happy to accept the gift of heat. The eco-managers had the idea of selling it on to citizens in Mauenheim. They were going to sell it for a price lower than that of heating oil. And the heat would be piped directly into the houses of clients, through a heat supply line.
The mayor of the nearby borough of Immendingen praises the project as a "far-sighted and single-minded initiative." What he especially likes is that energy costs "are no longer drained off, but remain in the area in the form of purchasing power." And Peter Hennicke, the president of the influential Wuppertal Institute for Climate, Environment and Energy, even sees Mauenheim as proof that "full supply using renewable energy sources is technically and economically possible on a local level."
Experts aren't the only ones who take this view. With electricity, oil and natural gas becoming increasingly expensive and the warnings from climate scientists getting louder, a growing number of people have taken energy supplies into their own hands. They ferment or burn local raw materials and distribute the heat produced via their own decentralized grids.
Rai-Breitenbach, a neighborhood in the town of Breuberg, in the south-central Odenwald area, is a good example. More than 150 home and real estate owners -- including the Breuberg city council -- have opted in favor of connection to a local heating grid. From 2008 onward, heat will be fed into the grid from a modern plant that uses wood as fuel. The planners have also considered using elephant grass, a tall reed with good biomass properties. As a backup for periods of high demand, they also may use a boiler for rapeseed oil.
As in most bio-energy towns, the model for this system was developed by the citizens themselves. "We had the necessary know-how right here, so we developed it ourselves," says Horst Stapp, the chairman of the Rai-Breitenbach co-op.
But the project may yet fail. A successful start still depends on local demand. Rai-Breitenbach has opted for heat only -- no electricity production -- so there will be no additional income from the sale of power. "We've chosen wood because we have plenty of it," says Stapp. But wood fuel is technically difficult to use in small power plants.
The people in Odenwald won't let that discourage them. They now want to market the knowledge they've acquired over the past 12 months and make it easier for other bio-energy villages to get started.
Citizens in Jühnde, in the state of Lower Saxony, got started about six years ago, when scientists at the nearby University of Göttingen asked 17 boroughs in the area whether they would like a decentral bioenergy supply. Four villages were shortlisted before the eco-researchers finally chose Jühnde, a village with a population of 775.
Heat delivery to Jühnde began in September of 2005. The core of the project is a biogas facility that ferments local raw materials like rye, wheat, sunflowers, maize and liquid manure from farmers in the region and uses the resulting methane to produce electricity and heat in a small power plant. A local heat grid carries the energy to (at the moment) 142 households. In other words, more than 70 percent of Jühnde's inhabitants use local bio-heat.
The operating company is a co-op with almost 200 members. It managed to feed 4 million kilowatt-hours of electricity into the grid during the first year -- replacing more than 300,000 liters (79,252 gallons) of heating oil. The co-op has proclaimed itself "mighty proud" of this achievement.
The Spread of Bio-Heat
Most of the co-op's members are also clients, which effectively means consumers fix their own energy prices -- so the heat is cheap. The price corresponds to .35 (47 US cents) per liter (0.26 gallons) of heating oil, which enables the residents of Jühnde to save about one-third of their usual heating costs. True, they also pay a basic charge of 500 ($672) a year. However, additional savings come through the fact that the homes connected to the net no longer require central-heating boilers, and the correlative maintenance costs cease to apply.
Jühnde has inspired others in the region to follow its example. The responsible district authority in Göttingen has already found eight additional boroughs which might be eligible for local heating grids. A feasibility study may be made available to these villages by fall of this year. And those boroughs whose citizens join the project may be supplied with bio-heat as early as the end of 2008.
Meanwhile Keller, the organic farmer in Mauenheim, gazes from his cowshed to his biogas fermentation tanks and takes pleasure in the fact that, since last winter, the waste heat from his small power plant has also been put to sensible use.
He may be giving the heat away for free, but Keller has guaranteed himself a lucrative additional income. Germany's renewable energy law says electricity should be remunerated with an additional .02 (3 US cents) per kilowatt hour when the heat is also used. This legal provision was introduced by Germany's last government, a coalition between the Social Democrat Party (SPD) and the Green Party, to encourage farmers to save energy -- and the strategy has worked out perfectly in Mauenheim.
© SPIEGEL ONLINE 2007
All Rights Reserved
Reproduction only allowed with the permission of SPIEGELnet GmbH