Advanced manure management systems are a highly effective method for mitigating the environmental impact of dairy farming. Apart from their abatement of atmospheric methane emissions, on-farm anaerobic digesters are able to produce a renewable source of energy. Farm operators at Alliance Dairy in Trenton, Florida consider this sustainable, full circle approach a no-brainer. After installing the digester system, Alliance Dairy closed the loop by implementing a generator for electricity production. Any of the captured dairy biogas that isn’t utilized for power or heat generation is combusted over an open flare. Any of the excess liquid from manure can be recycled as a nutrient-rich fertilizer for Alliance Dairy’s crop fields.
Prior to installing anaerobic digester technology in 2012, the dairy was storing manure in open lagoons. Without a cover, this manure decomposed under anaerobic conditions, releasing methane gas into the atmosphere. With the new system, Alliance Dairy sends manure to its digesters. The methane gas is then captured and destroyed in a 1,000kW generator to produce electricity and heat, thus displacing fossil fuel use. The amount of power Alliance Dairy produces is equivalent to the amount needed to power 425 homes annually. Aside from their ability to reduce harmful GHG emissions, dairy digester projects also improve air quality, add diversity to the fuel supply, and increase energy security with a renewable resource.
PROJECT TYPE: Alternative Manure Management
ONLINE DATE: 2020
LOCATION: Trenton, FL
VERIFICATION: Climate Action Reserve
RELATED SUSTAINABLE DEVELOPMENT GOALS (SDGS):
This project contributes directly to the achievement of the Sustainable Development Goals (SDGs) set by the United Nations:
The United Nations’ Sustainable Development Goals (SDGs) are an urgent call for action by countries in global partnership to end poverty, protect the planet, and ensure that by 2030 all people enjoy peace and prosperity.
Co-benefits
Installing anaerobic digester equipment eliminates the environmental degradation and climate pollutant emissions associated with the standard method of manure disposal into open lagoons. The liquid from the manure was recycled into fertilizer for Alliance Dairy’s fields, which benefited from its nutrients.
The anaerobic digesters produce effluent that can be used as organic fertilizer or animal bedding. Digester projects typically range from $5-20 million to implement. Carbon credits from avoided emissions provide the dairy with an important stream of revenue to help make these projects economically viable.
Digesters reduce manure odor in the local community, which can be significant in areas with large concentrations of dairy cows.
