Haubenschild Farms Final Report - The Minnesota Project

The Minnesota Project August 2002
In addition to this, The Minnesota Project received $67,500 from the MN Office of
Environmental Assistance, the MN Department of Commerce and Unity Avenue
Foundation to coordinate publicity, collect data, and document and evaluate the project.
Table 2: Project Financing for Installation of Digester
Source Type of assistance Amount
AgSTAR technical assistance $40,000
MN Office of Environmental Assistance grant $37,500
MN Department of Commerce grant $50,000
MN Dept. of Agriculture no-interest loan $150,000
Haubenschild Farms equity $77,500
TOTAL $355,000
System Operation
Operation of the digester and engine/generator requires a certain amount of “screwdriver
friendliness.” Dennis Haubenschild performs most of the operation and maintenance of the
digester. To help prepare Dennis for this task, Richard Mattocks conducted a series of
walk-around sessions on system operations. Routine operation takes approximately 45
minutes per day. This includes system inspection, mixing and pumping manure into the
digester twice a day, and checking and recording gauges to measure biogas and electricity
output.
The engine-generator requires the most maintenance. The engine oil needs to be changed
every month. Valve adjustment and spark plug cleaning is also performed periodically by
Dennis. Other routine maintenance performed since 1999 includes replacing the battery,
alternator and the mag needle (which creates the spark). It is estimated that engine
maintenance for an on-farm biogas engine-generator, including periodic engine overhaul,
costs about $3,700 per year. 19 Other operating costs include periodic maintenance of the
gas blower, gas flare and manure pumps and checking pipes for gas leaks.
In May 2000 the manure pump broke and required replacement under warranty. Because
Haubenschild Farms used a manure pump for manure management before the digester was
installed, this is not a potential problem unique to an anaerobic digester system.
On June 5, 2000, the generator circuit breaker blew out due to defective manufacturing and
was also replaced under warranty. The generator was out of commission for about four
days while this was being replaced. The biogas was flared during this period.
19 About 1.5 cents/kwh, as projected in the Charles Ross and James Walsh, “Handbook of Biogas Utilization,”
United States Department of Energy, Southeastern Regional Biomass Energy Program: Muscle Shoals,
Alabama, 1996.
18