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Farm Bill Funded Project
Clover Hill Dairy, LLC
| Location |
Campbellsport, Wisconsin |
| Project Type |
Farm Scale |
| Animal Type |
Dairy |
| Population Feeding Digester |
1,250 |
| Baseline System |
Storage Lagoon |
| Digester Type |
Mixed Plug Flow |
| System Designer |
GHD, Inc. |
| Biogas Generation |
115500 ft3/day |
| Biogas Use |
Cogeneration |
| Generating Capacity |
300 kW |
| Receiving Utility |
WE Energies |
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Photo: Energy Center of Wisconsin
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In 2007, Clover Hill Dairy installed a mixed plug-flow digester to treat manure that is continuously scraped and collected each day. The anaerobic digester system is a U-shaped concrete tank with a fixed concrete cover where manure and wastewater enter and exit from the same end of the digester. The design theoretically allows for future expansion on the enclosed end of the digester. A central wall houses hot water piping that heats the manure. The digester operates at a temperature of approximately 100ºF and has a hydraulic retention time of 20 days.
Biogas is treated and run through a 300 kW engine generator set to produce electricity. The farm owns the carbon credits associated with electricity production and has signed with the Pure Farm Energy® Producer Network. The Network is an aggregator and certifier of carbon credits for farm energy project owners. Heat from the water jacket and engine exhaust is collected and used to heat the digester, milk house, parlor, and feed lanes.
The farm uses a screw press separator to generate approximately 100 tons of solids each week. The farm uses 70 tons for on farm bedding and field application, and sells the rest to another dairy for bedding.
Clover Hill Dairy’s digester project includes the following benefits:
- Ownership of carbon credits for the production of energy
- Odor reduction
- Revenue from sale of excess bedding (~$600/week)
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