The Green Team’s ultimate goal was to play an instrumental part in getting a biogas digester built on a farm in our school district.
In order to achieve that goal, we needed to carry out field research on farms with existing electric producing biogas systems and prepare an informational presentation for a local farmer to use to make an educated decision on whether on not to invest in a electric generating biogas system.
To that end we traveled to two farms in Pennsylvania and conducted field research on the biogas systems.
The key findings from our field research are as follows:
- The savings in electricity does not alone justify the construction costs.
- The sale of excess electricity produced helps justify the construction costs.
- The use of post digested fibrous material (the solids in the cow manure) as bedding material, instead of sawdust or straw, significantly helps justify the construction costs.
- Processing organic wastes from off farm sources significantly contributes towards the profitably of the system by substantially increasing electric production.
- Capturing the waste heat from the engine exhaust contributes to energy savings and significantly increases the profitably of the biogas digester systems.
- The post digested liquid wastes are significantly less detrimental to the environment than the original wastes when spread onto the fields.
- Overall, large farms operating biogas digesters have a significantly reduced negative impact on the environment as a whole.
- Onsite electricity production is a win for the farmer, a win for the electric consumer, and a win for the environment