The Low Carbon Fuels Standard (LCFS) provides time for the development of advanced, near-zero technologies. However, having infrastructure already in place to deliver alternative fuels to fleets, once more alternative fuels are already in place, will ease the future transition to zero or near-zero transportation technology (e.g. biofuels, electric and fuel cell technology). This project aimed to complement The California Air Resource Board’s on-going work on technology assessment by exploring how the near-term development of natural gas infrastructure, in the heavy-duty transportation sector, can be implemented to include technology that can best facilitate the long-term conversion to near-zero technology.
The researchers found that infrastructure requirements for natural gas and renewable natural gas (RNG) have many synergies. Fossil natural gas network investors can benefit from receiving carbon credits by blending RNG into their fossil based natural gas fuel while RNG investors can save costs by piggy backing on existing fossil natural gas infrastructure. In contrast, the production of hydrogen with truck or hydrogen pipeline delivery would have minimal overlap with the existing natural gas distribution and refueling systems.
The analysis considers three possible natural gas pathways (CNG, conventional LNG, and onsite LNG) and five hydrogen (H₂) fuel pathways (on site, central H₂ delivered by truck, central H₂ delivered by pipeline, central H₂ blended and separated, central H₂ blended but not separated). H₂ stations with onsite steam methane reforming or H₂/natural gas blends delivered by natural gas pipeline, do have some potential overlap with natural gas distribution and refueling systems, but the majority of storage and refueling equipment are not compatible for both H₂ and natural gas due to the fact that H₂ is stored at higher pressures (require different compressor designs) and requires special materials. The timing for the likely build-out for hydrogen stations serving new, H₂-ready trucks and buses will be a decade or more later than the current expansion of the fossil natural gas and RNG networks, limiting the potential for synergies for overlapping infrastructure for commercial fleets. Natural gas fueling infrastructure built today will need to be refurbished or replaced within 15 years, while H₂ networks are likely to only reach wide scale adoption in that timeframe. The analysis shows that certain port and urban locations will favor renewable natural gas resources initially, but may be able to link to H₂ supply chains in the longer term.