Competition to make bio-fuels out of waste products that would otherwise have to be dumped is creating a fast-growing, worldwide industry.
And a German research organisation now believes it has perfected a system called a “biobattery” for turning a vast range of waste into energy.
The drive for better technology has been spurred on by criticism that the first generation of bio-fuels used productive land that should be used for food crops, rather than to grow plants for ethanol and other fuels.
That inspired scientists and governments to find ways of using everything from human waste to algae to power planes, cars and to make electricity.
So many new companies have sprung up to exploit this new market and try to gain big backers for their projects that there is even a daily internet news site, BiofuelsDigest, just to keep up with developments.
Germany has been the leader in Europe because it has made the political decision to phase out nuclear power and replace it with renewables.
We can utilise a number of raw materials that would otherwise have to be disposed of, often at great cost.
Professor Andreas Hornung, director of UMSICHT in Sulzbach-Rosenberg
Biofuel plants are a key part of this revolution because the gas they produce is used to make electricity to balance out the shortfall when solar farms and wind turbines are not producing enough power.
There are already 8,000 plants in operation in Germany, with an electrical output of 3.75 gigawatts in total − the equivalent roughly to three nuclear power plants. Some of these are the first generation that use food plants to make fuel, and so remain controversial.
However, the Fraunhofer Institute for Environmental Energy and Safety Technology(UMSICHT) in Germany has developed the biobattery, which uses sewage sludge, green waste, production residues from the food industry, straw and animal excrement to create electricity, heat, purified gas, engine oil and high quality biochar (a form of charcoal).