Turning Brazil's biomethane potential into a scalable fuel for urban transit, given its cost premium to competing options, could take long-term purchase contracts, tax credits and investment in distribution networks.
Brazil has started testing biomethane in buses, with multiple projects in different regions, including the city of Sao Paulo, which has nearly 14,000 buses in its municipal fleet.
"If we consider just 10pc of that fleet, we will need around 110,000 m³/d of biomethane," said Ricardo Vallejo, head of market intelligence at natural gas company Commit.
The pilot project's main objective is to verify operations, such as if engines running on biomethane meet power, torque and other specifications and avoid other problems, Vallejo said.
Espirito Santo state's government used biomethane for two public transport lines in partnership with bus manufacturer Volare. It has developed a new model to run on natural gas and biomethane, with a range of up to 450km (280 miles). But the model is 40pc more expensive than Volare's conventional diesel-fueled bus.
Goias state's government ran an 87-day test with biomethane-fueled buses starting in March. It used biomethane produced in the region through partnerships with ethanol companies Jalles Machado and Albioma and referenced a cost of R4.4/km ($0.7896/km), or R3.04/km excluding biomethane delivery costs.
This puts biomethane costs above those of both diesel and electric vehicles, which were referenced at R3.11/km and R2.64/km, respectively, for the test comparisons.
But state incentives for biomethane could make it competitive even with higher fuel prices, according to the deputy secretary of Goias, Miguel Angelo Pricinote. Goias' tax incentives include ICMS VAT-like credits of 85pc for operations inside the state and 90pc credits with other states, he said.
"We acknowledge challenges such as the cost and environmental footprint associated with transporting biomethane via trucks as well as the need to scale up production to continuously meet contracted demand," Pricinote said.
