17 September 2012 – In Rhede, Germany, since 1752the Wenning family has run a successful agricultural business and distillery. Thirty years ago it took the first steps towards on-site biogas production. Together with the help of Atlas Copco, it has evolved into an energy producer that uses less power than other comparable plants.
In Europe, the target is that by 2020, 20% of all energy and 10% of all transport fuel should come from renewable sources. To reach these targets, European countries are rethinking their energy mix. Germany is promoting biogas as an alternative source of energy. “In comparison with other sources of energy, like electricity, the biggest advantage is storability. We can store up to two months’ worth of energy,” Bernd-Josef Wenning says. As biogas is stored in the existing gas network, it doesn’t have to be consumed immediately and no additional investments in the gas grid are required.
In Germany, over 6,000 anaerobic digesters convert biomass into raw biogas. This numberwill more than double over the next ten years. “The energy cycle is simple: the distillery contributes with residues that feed the bulls,” Wenning explains. “The bulls give manure in return, a raw material for the biogas plant. The plant delivers gas, which is used to generate electricity and steam. This is a closed loop that really makes sense.”
There are two possibilities for biogas; cogeneration and as substitute to natural gas (upgraded biogas). As cogeneration is only effective as a local source of electricity and heat, and is less efficient when the heat is only used at certain times of the year, upgrading the biogas to biomethane offers better opportunities. By 2020, biomethane is expected to provide 10% of Germany’s overall gas demand.
“Biomethane offers a twin benefit. First, we gain energy. Secondly, we avoid energy costs. On the one hand, we obtain gas, energy we can use for all sorts of things. On the other hand, the output of a biogas plant can be used as fertilizer, reducing the burden on the environment.”