White Paper

The final report is available for download here:
MD/HD Infrastructure Standardization White Paper

Based on the assessment, the folloiwng conclusions were drawn:

  1. Kilowatt-level charging is well established but will not meet all MD/HD-BEV operational use cases. Mature standards provide options up to 350-450 kW. However, available charging rates are insufficient for fleets that operate larger vehicle classes, have longer routes, and/or have little downtime between shifts. While higher charging rates are needed to support many heavy-duty applications, fleets may find a trade-off between installing higher power systems and cost.

  2. New standards that permit higher charging rates and greater flow rates for hydrogen fueling are needed to meet fully the range of expected MD/HD-ZEV applications. Several standards in development are focused on supporting increased charging power and faster hydrogen fueling rates in order to achieve reasonable MD/HD-ZEV charging and hydrogen fueling times. Not only will these new standards support on-road MD/HD-ZEV deployment, but they will also become the foundation for other applications, such as larger off-road equipment, aviation, rail, and shipping, which will all need to be addressed to meet the state's 2045 emissions reduction targets.

  3. Increased reliability is needed to support the broad market utilization of MD/HD-ZEV infrastructure. Electric LDV charging and hydrogen fueling stations have experienced outages and other operational challenges that interfere with the consumer experience. For LD-ZEV and especially MD/HD-ZEV stations, it is essential to enhance reliability by mitigating issues associated with communication and component failures, and hydrogen supply. While the industry is actively engaged in efforts to tackle these issues, policy and government oversight that assures maintaining an acceptable level of overall performance of charging and hydrogen fueling stations is priority one.

  4. The continued improvement and prioritization of cybersecurity for ZEV stations is also a high priority. Station providers are leveraging several tools, including updated standards and best practice recommendations, to strengthen station cybersecurity. However, a standardized, robust cybersecurity approach across the ZEV infrastructure markets is lacking. State and federal governments have directed action on cybersecurity for charging stations, including California mandating security standard PCI-DSS for payment systems at public stations (SB 454) and the federal NEVI formula program requirements, including compliance with OCPP and 15118. Hydrogen stations have similar risk vectors and advancements in encryption and security standards can be equally applied across both station types.

  5. Due to the wide range of vehicle classes and applications within the MD/HD sector, a combination of station configurations is needed to meet MD/HDV needs. MD/HD ZEV adoption necessitates the deployment of both charging and hydrogen fueling stations. While for BEV charging, AC level 2 charging may be sufficient for some medium-duty applications (e.g., shorter route applications and last mile delivery), DC fast charging up to megawatt level charging will be required to support larger vehicle classes and longer-range vehicle applications (e.g., long haul).

  6. For hydrogen fueling, current station configurations in California include two pressure classes: 350 and 700 bar. Future hydrogen station sizing will vary depending on the number of vehicles with access, and station hydrogen storage will be either gaseous or liquid depending on the hydrogen supply and station size.

    Furthermore, fleets using either BEVs or FCEVs may require a combination of private (fleet-based) and public infrastructure to ensure a resilient fueling network. These station variations will need to be appropriately considered in code requirements and public funding solicitations.

  7. Several challenges, outside the scope of this study on standards, hinder the broad deployment of MD/HD-ZEVs.These challenges include vehicle and fuel supply constraints, cost, and training. Limited ZEV options are currently available for a range of vehicle applications and potential station locations are hindered by a lack of sufficient electric grid capacity and the need for utility upgrades. Similarly, the supply of renewable hydrogen will need to significantly increase to meet future MD/HD-FCEV demands. Capital costs for ZEVs and their associated infrastructure remain prohibitive for many fleets. Lastly, the expansion of ZEVs and infrastructure requires that technicians and emergency services are trained in new, high voltage systems as well as hydrogen-specific systems to ensure station safety.

Based on the conclusions of this study, the following policy considerations are recommended:

  1. Policies for MD/HD-ZEV stations should strike a balance between the need for standardization and the promotion of on-going innovation.
    While key areas of focus for required codes and standards are safety, security, and reliability (including interoperability), policies should provide a flexible framework that establishes effective codes and standards but promotes innovation and allows for the integration of new technology advancements.

  2. In public funding solicitations, differentiate station type and configuration, including public versus fleet-only access, when setting codes and standards requirements.
    For example, private stations may be allotted additional flexibility in design to meet the specific requirements of the target fleet. On the other hand, public stations are oriented towards providing services to the greatest number of vehicles as possible, which will require a higher standard for interoperability as well as faster charging rates and hydrogen fueling rates to promote high station throughput.

  3. Promulgate "short term" guidance for charging and fueling protocols employed in MD/HD commercial stations with the goal of facilitating interoperability.
    Technologies and standards are in development (e.g., SAE J2601-5) with timelines for completion between one and three years, and stakeholders will need to determine the manner in which to adapt in near-term station development. The government can (1) encourage and support technology development efforts conducted through public-private partnerships (e.g., U.S. DOE National Laboratory research and industry consortia) already testing new technologies and methods to inform the new generation of stations, (2) monitor the status of standards, and (3) provide guidance on how stations can support continued interoperability in the short-term given the different generations of stations and vehicles. Given the need for State agencies to closely monitor the evolution of MD/HD charging and fueling industry standards, it may be prudent to consider direct observation of relevant standards committees. Furthermore, a State committee administered by the Office of the Governor (e.g., GoBiz) could coordinate an effectual exchange of observations and oversee the assignment of agency observers.

  4. Require compliance with TIR documents that are pending finalization of formal standards for high power and high flow systems in public funding solicitations.
    TIRs are valuable guidance documents that signal the direction of on-going standards development and have been previously used for this purpose. At the time of this report, SAE J2601-5 TIR was recently released and a TIR for SAE J3271 is in draft. These TIRs are available in advance of planned full standards. Referencing these documents can prepare stations to be compatible with upcoming standards.

Overall, transitioning to 100% MD/HD-ZEVs in California requires significant investment and coordinated, regional planning efforts. The State has a responsibility to establish infrastructure requirements that support the rapid deployment of a reliable, interoperable MD/HD-ZEV infrastructure network without hindering technological advancement within the market. To date, federal, state, and regional agencies have played a critical role in supporting technological maturation and standardization of MD/HD-ZEVs and the associated infrastructure through direct funding, program guidance, tools, and policies.

Based on the findings from this study and lessons learned from the LDV market deployment, a systematically planned agency strategy is appropriate to assure MD/HD-ZEV charging and fueling stations are designed, constructed, and operated to be:

  • Compliant with industry standards, such as ISO, SAE and IEEE for operability and NFPA for safety, to be
  • Reliable and thereby instill market confidence and accelerate market engagement, at levels (e.g., 98% dispenser availability) commensurate with existing fueling infrastructure, with enforcement to assure maintenance of the reliability over the life of the station, and to
  • Leverage industry innovation, by allowing MD/HD design flexibility to consider future improvements.