California has the potential to produce 85 % of renewable natural gas ( RNG ) for use in transport by 2020 , according to a study for the California Air Resources Board ( ARB ) . The study also found that pipeline adoption would be wider if combined with federal subsidies . California has the capacity to produce 90.6 billion cubic feet ( bcf ) per day of RNG . However , obstacles to large - scale use are the possibility of upgrading and replacing existing pipelines .
California has the potential to produce 85% of renewable natural gas (RNG) for use in transport by 2020, according to a study for the California Air Resources Board (ARB). The study also found that RNG adoption would be wider if combined with federal credits. California has the capacity to produce 90.6 billion cubic feet (bcf) per year of RNG. However, obstacles to large-scale use are the cost of upgrading and interconnecting existing pipelines.