Ottawa Valley Farm Producing its own Heat and Power

The Klaesi Farm (a 140 tie-stall dairy operation located in Cobden, Ontario) anaerobic digester (AD) digests the manure from the farm's 160 cow dairy operation and produces sufficient biogas to meet the electricity and heating needs of the farm and farm residences.

The system, which was built and operated by the farmer without government subsidies, is unique in that it is the smallest of its kind in Canada and demonstrates that AD can be feasible at a typical farm. Other benefits include odour and pathogen reduction, weed seed destruction, and improved fertilizer characteristics.

Except for some problems associated with operating the system's engine generator set, the system has run smoothly for over 2 years. Klaesi Farms is currently participating in an economic and environmental assessment of anaerobic digestion being funded by Agriculture and Agri-Food Canada 's (AAFC) Environmental Technology Assessment Program (ETAA) program. The objective is to evaluate the benefits of small scale AD systems in terms of digester operation and performance; land application of digested manure; and air and water quality.

Natural Resources Canada (NRCan) is also providing financial support to conduct R&D at the site through the Technology Innovation Program and in partnership with the Ontario Ministry of Agriculture, Food and Rural Affairs (OMAFRA) and the Klaesi Farm. The overall R&D goal is to test the digestion of off-farm cosubstrates, such as waste cooking oil, and to measure their effects on biogas production, pathogens, etc.

Phase I of the project consisted of testing and modifying imported generator technology for use under Canadian operating conditions. Phase II will consist of testing off-farm co-substrates. The work undertaken during Phase I was presented at the Integrated Solutions to Manure Management in the spring of 2006.

The Klaesi anaerobic digester is a Bohni mesophilic (40 o C) digester system from Switzerland . The digester is 500 m 3 with a hydraulic load of 15-20 m 3 /day and a retention time of 25 days. The digester was built into the existing manure pit. A rubber membrane on top expands or contracts depending on the amount of gas that is collected. When the gas is drawn off, the digested manure is moved to a second holding tank for storage.

The digester is equipped with a 50 kW Schnell generator. The digester produces on average 480 kWh/day of electricity and the generator motor generates 300,000 Btu/hr of heat. Heat produced by the generator is used to heat the digester, onsite buildings and the two farm houses in the winter. The electricity produced is net metered for use on-farm.