Rising fuel prices make bioenergy production on farm in Germany attractive

There can be no questioning of Hartmut Pahmeyer’s desire to become independent from the global fuel market. Nor can you doubt the German farmer’s ability to innovate successfully to meet his aims.

For the past four years he has been running five tractors and a Claas Lexion 530 combine on 100% rapeseed oil and, while it is true to say he is not alone among German farmers in doing that, what makes Mr Pahmeyer more unique is that it is his and his two farmer partners’ ideas that designed the oil presses he uses on the farm.

“We have a factory in the south of Germany that makes the presses,” he explains. “Last year our company, Kern Kraft, sold 540 machines worldwide. We have the highest market share in Germany for small presses.”

It is the simplicity of the presses which Mr Pahmeyer believes makes them successful.

A typical press that can process 250t of oilseed a year costs €7000. On Mr Pahmeyer’s farm in Eggeberg, Halle-Westfalen, west of Hanover, he uses 10 of these machines to crush around 2500t of rapeseed from his 60ha rape crop each year, producing 38 litres of oil/100kg rapeseed.

Two-step proces

The oilseed is stored above the presses in an old barn, and is crushed in a two-step process. “The quality of the oil is very high – it could be used for cooking – and consistent. When you make your own oil, you know the quality is the same. If you buy it, you don’t know whether it is good or bad. That’s why it is important for a good farmer to make his own.”

The oil is then filtered before being used in the tractors or combine. Each has been modified to have a two-tank system – a small tank holding diesel, as well as a tank for the rapeseed oil, again designed on farm.

“It is not good for the engine to start using rapeseed oil,” he explains. “You need to start with diesel and then after about five minutes switch over to rape oil.”

The tractors also have to be working hard to run effectively on the oil, he says. “The tractor needs to be hot enough, working hard, so you have to think carefully about what you’re doing.”

Performance is similar to diesel, he claims. “I use around 5% less oil than I would diesel the oil has more energy in it than diesel.”

The twin-tank system cost him around €500 to build and install. “It is established technology. You can buy it on machines from Deutz or Fendt, but it would cost considerably more.” Volvo, for example, charges €8000 for a similar system, he says.


The switch saves him around €0.40/litre. “It costs me €0.80/litre to produce the oil, against €1.20/litre for diesel. If you sell the rapemeal it works out at €0.60/litre.”

Currently the rapemeal attracts around €25/100kg for animal feed, but Mr Pahmeyer has grander plans for the by-product. From this month it will be used as a feedstock, along with slurry from his pigs, to produce biogas.

Again, he has been heavily involved in the design of the system. “A lot of farmers have built biogas plants, but the problem is that the industry earns the money, not the farmer. They are very expensive to build – for a 300kW-400kW plant it costs €1-1.5m to build, so the farmer is paying for it the entire life of the plant.”

Biogas plants also tend to be very complicated. “There are a lot of electronics, so it is difficult to operate for the farmer.”

Mr Pahmeyer’s aim was to build a very simple plant. “The important thing is to have very liquid fermentation,” he explains. Around 8cu m of slurry and 1t of rapeseed meal will be pumped around a fermenter, before being transferred into a secondary fermenter, from which methane gas is extracted, and converted into electricity.

Small-scale pilot tests proved the technique worked. The newly built plant is due to come on-stream this month, producing around 80kWh of electricity, which will be used to power and heat the farmhouse and stables. Any spare electricity can be sold back to the national grid.

“It is another step to becoming independent from the energy market. If a lot of farmers built such systems we might be able to influence the market.”

Kern Kraft press in action

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