6.3 Total biogas production costs to produce biomethane for vehicles
The total production costs for upgraded biomethane suitable for use in vehicles are lowest for systems based on wastes or sewage, where feedstock costs are non-existent and capital costs are low. Biomethane upgraded for use in vehicles can be produced for between USD 0.45 to USD 0.55/lge from wastes or sewage (Figure 6.6), but this range increase to USD 0.65 to USD 0.75/lge when some maize silage is also purchased. Large-scale production will, however, require the purchase of feedstocks (e.g. maize silage) for the majority of the throughput. It will therefore be more expensive, even after taking into account the economies of scale from moving to higher production capacities.
When maize silage is the primary feedstock, production costs for biomethane will be between USD 0.73 and USD 0.93/lge when water scrubbers are used to upgrade the raw biogas and between USD 0.75 and USD 0.87/lge when amine scrubbers are used.
There is little difference between the amortised capital and operating costs of the two upgrading systems examined. The most recent data suggests that upgrading systems based around water scrubbers will be somewhat cheaper than amine scrubber systems for capacities up to 1 000 Nm3/hour raw biogas processing capacities (Bauer, 2013). However, cost differences become very small at higher capacities, and the key factor determining a choice will be the technical performance of the system depending on the biogas composition and the biomethane quality requirements.
Figure 6.6: Total production costs for biomethane suitable for vehicle use by upgrader type and size
Sources: IRENA analysis; Urban, 2009; and Bauer, 2013.