Anaerobic digesters reduce GHGs much info at this site:

[JohnWxy]

http://res2.agr.gc.ca/initiatives/manurenet/en/man_digesters.html#CHP


Manure digesters, especially those with co-generation capabilities, may deserve another look in Canada, especially with increasing volatile energy costs, and increasing concerns about greenhouse gas emissions, odour and pathogens in manure.

The technology of anaerobic manure digestion has the potential to accomplish the following:

Greatly reduce odour levels during manure processing, creating a relatively odour-free end product (closed vessel processing confines odourous compounds which are converted to other chemicals). Digested manure, which could be subsequently applied to land, would not have more odour associated with it than would composted manure.

Reduce pathogen levels in the final products. Anaerobic digestion greatly reduces pathogen levels. Additional pre- or post-digester technologies can ensure pathogen-free end products.

Conserve nutrients - more than 90% of nutrients entering anaerobic digesters are conserved through the digestion process. By conserving nitrogen during digestion, the N:P ratio of the treated manure is more favourable for plant growth. Reducing the demand for additional mineral nitrogen helps decrease the use of natural gas for production of new mineral nitrogen, as well as reduce greenhouse gas emissions associated with nitrogen fertilizer production.

Reduce greenhouse gas emissions - Since anaerobic digestion operates in a closed system, substantial reductions in greenhouse gas emissions (methane, nitrous oxide) are achieved. Ammonia losses, while not of direct ghg concern, are also reduced. Ammonia is now on the list of toxic substances under the Canadian Environmental Protection Act (CEPA).

Co-generation and Energy Independence - Anaerobic digesters produce methane which can be captured for supplying energy (heat, electricity) for the operation, thereby achieving substantial cost recovery. With the increasing privatization of power generation utilities, the "net cost" of power delivered to the farm is rapidly increasing, and energy independence for the farmer is rapidly becoming an attractive option. Often the delivered cost of electrical power will be at least double the original generating costs. The decision to co-generate electricity should primarily be driven by the savings for meeting the farm's power requirements, rather than based on potential sales of excess power back to the grid, if allowed. Net metering laws are now starting to be implemented in numerous American jurisdictions, which may further improve the economics for co-generation

[kestrel91316]

1. If you want to buy carbon offsets that go toward funding this sort

of biogas power production, or wind-generated power on the Rosebud Reservation, SD, check out NativeEnergy's website.

http://www.nativeenergy.com/