Biomethane is often overlooked as a viable transport fuel option, yet when produced from wastes can provide a highly competitive, low-cost transport fuel alternative. Biomethane upgraded for use in vehicles can be produced for USD 0.45–0.55/LGE from wastes, and USD 0.65–0.75/LGE when maize silage is added.

Large-scale production requires the purchase of feedstocks (e.g. maize silage) for much of the throughput and is thus more expensive. The cost of upgrading to biomethane must be added to production costs for biogas, but this typically only accounts for 5–10% of production costs. The main constraint to the expanded use of biomethane is the need for a dedicated gas-based refuelling network and the relatively limited quantities of waste feedstocks relative to total transport demand.