German Farmers Create Energy From Crops
When Gerold Fuge and Mark Landfried merged their German farms more than 10 years ago, their goal was simple – the pair wanted to create a more sustainable future for their operations.
Part of that goal included becoming more energy-efficient. For years, the farms had relied on nuclear power to provide electricity.
Nuclear Power in Germany
The first commercial plant came online in 1969. From the very beginning, it was a highly contested issue in the country. Yet, the debate didn’t slow down development and by 2011, Germany had 17 reactors.
After Japan’s Fukushima nuclear disaster in 2011, the topic received renewed attention. Within days of the incident, large protests began to break out, which prompted the decision by Chancellor Angela Merkel to shut down all of Germany’s nuclear plants by 2022. Eight of the 17 reactors were immediately shut down after Fukushima. There are only eight reactors left operating today.
Nuclear power in Germany accounted for 17.7% of the country’s electrical supply in 2011, compared with 22.4% the prior year. As of 2017, reliance on nuclear power continues to decrease as the country looks to alternative sources.
“Renewable energy is on the rise in Germany,” says Fuge. “Windmills, solar panels, and biogas are all being utilized.”
Not only is the country working to rid itself of relying on nuclear power, it also wants to reduce its reliance on natural gas.
“We have to buy natural gas from Russia because there is a very small amount available in western Europe,” he says. “There is a little in Norway, the United Kingdom, and Scotland, but most of it comes from Russia. What happens when there is a political issue or the relationship goes bad and Russia shuts down our natural gas supply – what will we do then?”
By building a biogas plant on their farm, and utilizing the crops they grow, Fuge and Landfried have been able to create their own energy source.
By the numbers
The initial Investment for the plant was about $2.5 million euros (around $2.9 million U.S.).
“We hope to see a return on our investment in 15 years,” he says. “It depends on what repairs we have to make along the way or if the government adds more mandates like it did three years ago and we had to invest in a burner tube. If the motors break down and you can’t use the biogas, you have to burn it down the tube.”
There are 200 hectares (around 500 acres) dedicated to growing crops for the plant – 175 hectares of corn and 25 of grass. Together they produce around 10,000 tons of silage annually.
“Only green crops can be used in this biogas facility. When the corn is 40% dry matter or higher, it’s not usable as silage because it’s not wet enough,” he explains. “You can use any variety of grass, but we use a special one from Hungary called szarvasi,” Fuge says.
The corn and grass are combined in a bunker silo; 85% of the silage is corn and the rest is grass. “There are about 8,000 biogas facilities in Germany doing this with farm crops and about 2,000 with food waste,” he says.
Biogas is being produced around the clock, 365 days a year. “It’s about 14,000 kilowatt hours per day or roughly 4.5 million kilowatt hours per year, which is enough energy for 1,200 households,” Fuge explains.
“The total efficiency of the biogas process is about 80% of the energy we transform into electricity and warm water,” he says. “When you generate electricity out of coal, only 30% of the power inside the coal can be transformed into electricity.”
Fuge adds that the biogas contains about 50% methane, and the rest is CO2 and a little bit of oxygen. It takes about 150 days to get the gas out of the silage.
“It’s about 80 days in step one, and then it goes through the second step for another 70 days,” he says. “The split process from first fementor to second fermentor is meant to get as much energy out of the silage as possible. Research has found that splitting it like this is the better process because you get two chances to get all of the energy out. It’s also an efficient system for transforming crops into energy.”
An added bonus for the pair is a partnership with a local mill to utilize the thermal energy from the biogas plant.
“They are making flour out of wheat and malt out of barley for brewing beer at a mill in town,” Fuge says. “The malt is very wet and it has to be dried down to around 15% moisture. They need a lot of warm water for heat to dry the barley.”
Roughly half of the 4.5 million kilowatt hours being generated from the biogas plant are used for electricity; the other half is thermal power used to dry down the barley.
“About 14,000 kilowatt hours is electricity and 12,000 kilowatts is for warm water,” he says. “We are replacing the natural gas they would have used to dry down the barley 1:1 with biogas.”
How they get paid
As a separate company, the two farmers are paid for the time they put in at the plant. In addition, they are paid per ton for the silage.
The pair also receives about 20¢ per kilowatt hour from the government, which Fuge says is based on a tiered pricing system.
“The base price starts at around 10¢ per kilowatt hour,” he says. “We receive various incentives. For example, in 2017, the government said when there is also replacement of natural gas with the warm water, you receive an incentive of 3¢ per kilowatt.”
In addition, the Fuge and Landfried have two tanks, about 8,000 cubic meters in total, to hold the dark, liquid slurry byproduct from the silage, which is used as fertilizer on their fields.
“It’s just like spreading manure,” Fuge explains. “Most of it is spread in the springtime before corn is planted.”
While experts say biogas is expensive electricity, Fuge believes it can close the gap when there is no sunshine or wind.
“Wind and solar panels are viable alternatives, but unlike wind and sun, biogas is a resource that can produce electricity and heat 24/7,” he says. “Biogas gives the grid managers that added flexibility as a reliable backup.”