A Techno-Economic Study of a Net-Zero Renewable Energy Supply for a Farm

Abstract

This study investigated utilising on-site organic waste from a large-scale dairy farm to provide sustainable electricity and heat. The 600-acre site required 65.2 kWe (electricity) and 9.54 kWth (heat). ECLIPSE software was used to simulate anaerobic digestion (AD) of livestock waste, wheat straw, and barley straw to supply biogas to a cogeneration system. AD produced sufficient biogas to meet all electrical and heating demands from a 100 kWe CHP system, alongside a biogas storage option. The study revealed that a maximum production of 1 MWe can be achieved using four 250 kWe units. Simulations of amine absorption carbon capture demonstrated that 85.1% of the CO2 could be removed from the CHP flue gases. Annual CO2 emissions are calculated by displacing current farm emissions, reducing grid usage, and implementing CCS. This results in a reduction of 117 tCO2e/year, 1692 tCO2e/year, and 6158 tCO2e/year for the 100 kWe, 1 MWe, and 1 MWe with CCS systems respectively. Economic analysis shows that the levelised cost of energy for the 100 kWe and 1 MWe options were £60.41/MWh and £47.34/MWh respectively for a lifetime of 20 years. The respective payback period ranges were calculated to be 1.9-4.4 years and 3.5-10.8 years.