Transportation fuels are more expensive on an energy basis (i.e., dollars per BTU) than other fuels and are usually thought to be the lowest hanging fruit, especially in conjunction with low carbon fuel standards that accord and additional financial incentive based on the carbon intensity of hydrogen relative to fossil fuels. Renewable gas standards for pipeline gas, replacement for existing fossil-based hydrogen industrial uses (e.g. fertilizer and refining) can also become cost-effective pending decarbonization regulations placed on those uses.