Manure: new source of renewable energy

In 2008, Dairy Manure from 3 stares contributes to half of 125 digesters installed in USA. PA, NY and WI are large Dairy states with the most installed anaerobic digesters.
In Europe, UK and Germany lead the installed base with > 70% energy generated by digesters. There are 1000s of Digesters in Europe and only 125 in USA. We have tapped less than 2 % of the energy potential from this renewable source: Manure.( 6500 farms are potential sites for digesters) Environmental Impact

Digester Gas, Methane (CH4) is 20x more harmful than CO2. Burning CH4 and converting it to energy, solves the GHG emissions problem and CO2 offsets (direct and indirect) can be encashed with the imminent cap-and-trade regs system.

Technology

One of the problems with the experience of farmers in USA is the bedding contamination in the digester. Most large farms (CAFOs) in USA have cows bedded on Sand. Cows on Sawdust or woodchips are prone to higher cull rates and poor milk quality. Cows on Sand, on the other hand, have longer life, live healthy and produce better and more milk.

But sand clogs the digester. There is need to eliminate the sand from the digester before it can get to the digesters. Over the last decade, 90 out of 100 digesters stopped working due to contamination, or lack of proper anaerobic process technology.

Nowadays, complete mix technology, a process started in Europe, is catching on.. The issue with sand is being addressed with a removal process installed in farms with about 95% to 99% removal of sand. The Parkson sand saver can be viewed on YouTube.