Lunen, a North Western German town is about to give an example of distributed recycled energy network, by installing a biogas plant to supply 30 to 40% of its energy needs (including heat).
The project, aimed to be finished by December 2009, will have a central biogas digester, that will be fed with all kinds of biodegradable materials, such as animal residues, crop waste, and other biomasses. These materials will ferment, releasing methane and CO2.
This has been done before. What’s new in their approach is that the methane will be fed into a biogas network, and taken to twelve strategically-distributed CHP (combined heat and power) units, provided by Schmitt Enertec, that will burn the gas, spin a turbine, and produce electricity. The remaining heat will help the town’s already functional heating networks.
The twelve CHPs will be connected to the digester through a special piping network, using a horizontal drilling technology, so they won’t have to dig the entire town in order to install the gas pipes.
The result will be the generation of 6.8MW of almost CO2-free power, enough to provide heat and electricity to about 25,000 homes. Anyway, the emitted CO2 will re-enter the normal recycling path, since it would have been drawn from renewable resources, grown locally in less than a few years (unlike oil, that is already buried into the grounds for millions of years).