Anaerobic Digestion of Dairy Effluent in New Zealand, Time to Revisit the Idea?

The anaerobic digestion of New Zealand low-input dairy farms has previously been evaluated for energy production, but farming systems have recently become more intensive with increased feed supplementation and feed replacement; therefore, we are studying how these changes affect the overall energy production for water heating. A combination of literature review, surveys, chemical analyses, biomethane potential analysis, and modeling were used for this study. On a case study farm with a solid separator, it was found that 558 MJ/day and 176-861 MJ/day could be produced with the solid and liquid portions of effluent, respectively. There is enough biogas to satisfy the dairy farm's water heating requirements with a tankless water heater.

Automated summary

The study investigates the impact of intensified farming practices on the energy production for water heating in New Zealand low-input dairy farms. A combination of methods including literature review, surveys, chemical analyses, biomethane potential analysis, and modeling were used. Results showed that 558 MJ/day and 176-861 MJ/day of energy could be produced from the solid and liquid portions of effluent, respectively, which would be sufficient for water heating needs of a dairy farm using a tankless water heater.