Clover Hill Dairy, LLC
|Project Type||Farm Scale|
|Population Feeding Digester||1,750|
|Baseline System||Storage Lagoon|
|Digester Type||Mixed Plug Flow|
|System Designer||DVO, Inc. (formerly GHD, Inc.)|
|Biogas Generation||115,500 ft3/day|
|Generating Capacity||480 kW|
|Receiving Utility||WE Energies, Inc.|
Farm Bill Funded Project
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 100°F and has a hydraulic retention time of 20 days.
Biogas is treated and run through two engine generator sets with a total electrical capacity of 480 kW. The farm owns the carbon credits associated with electricity production. 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)