The Biogas to Power projects utilize a range of organic feedstocks similar to the RNG projects, including dairy manure, food waste, source-separated organics (SSO), Industrial, commercial, and institutional (IC&I) waste, yard waste, agricultural waste, vegetable biomass, and fats, oils, and grease (FOG).
The biogas yields from anaerobic digesters or lagoon digesters for these projects are comparable to RNG projects, containing 50% to 70% methane or approximately 500 to 700 Btu/scf heating value. To meet fuel quality requirements from reciprocating engine generator manufacturers, we condition the raw biogas through customized biogas conditioning equipment, desulfurizing and dehydrating it.
These Biogas to Power projects employ high efficiency reciprocating engines, typically ranging from 250 kW to 4,500 kW capacities, in single or multiple parallel configurations. These engines boast electric efficiencies between 38% to 42% and overall efficiencies exceeding 85%, or 4,015 Btu/kWh heat rate, by utilizing waste heat for digester heating or space heating purposes.
The sizing of the power generation island is determined by various factors, including biogas generation potential, coincidental power and thermal demand, and grid economics. These Biogas to Power projects are typically sized to meet or exceed PURPA efficiency for FERC Qualifying Facility certification, with NOx emissions of 0.6 g/bhp.hr and lower.
