Dairies have long faced the challenge of handling their biggest milk making by-product - MANURE. Traditional methods are not pretty as can be seen in the graphic that follows:
Now, 3 dairy farms in Enumclaw are teaming up with a Skagit county based company called Farm Power Northwest to construct an anaerobic digester to process this waste. The new company will be called Rainier Biogas. The $4 million project includes a 1-million gallon digester vessel and is expected to generate enough electricity to power 600 homes. In addition, the elimination of manure lagoon methane emissions combined with clean electricity will reduce net greenhouse gas emissions by an estimated 9,000 tons of CO2 per year - the equivalent of removing 2,200 cars from our roads.
Anaerobic digesters rely on naturally occuring micro-organisms to break down or digest the waste, producing waste gas that can then be harnessed to produce electricity. This technology has been around for many years, but what has changed is that it is now much more affordable to use for smaller scale projects. King County has committed $492,000 to the project with funding provided by Federal grants. The project is expected to be up and running in 2012. Appears to be a great step forward for sustainable agriculture right in our backyard.
For those interested, following are two more graphics, first of the new process flow and then of the digester process.