California's plan to reduce carbon emissions from transportation anticipates a mix of battery-electric and hydrogen fuel-cell vehicles.

Recharging batteries from the electric grid is relatively simple, but producing hydrogen fuel requires a good deal of energy to split pure hydrogen out of other compounds.

To ensure that the carbon footprint of fuel-cell vehicles is significantly lower than that of gasoline or diesel cars, the state mandates that one-third of the energy used to produce hydrogen fuel be from renewable sources.

DON'T MISS: California Air Resources Board Head: All New Cars Should Be Zero-Emission In 2030

Under Assembly Bill 8 (AB8), passed in September 2013 by the California Legislature, the state will fund at least 100 publicly-available hydrogen fueling stations over several years.

The state has committed $20 million a year through 2024, and thus far, 48 hydrogen stations are planned and funded.

Light-duty vehicle type scenario, now-2050 (California Air Resources Board)

Light-duty vehicle type scenario, now-2050 (California Air Resources Board)

But using 1 kilowatt-hour of grid electricity to recharge an electric car will get you 3 or 4 miles of travel, whereas you'll get a lot less than that from a fuel-cell car.

Both vehicles use electricity to power electric motors that drive their wheels, but on a wells-to-wheels basis, there are more steps--and hence greater reductions in efficiency--to get the electricity from hydrogen than from the power grid.

In addition to the carbon footprint of the electricity generation itself, there's carbon associated with the hydrogen feedstock.

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And, there are energy losses at every stage as that 1 kWh of electricity is used to separate the hydrogen, which must then be compressed, transported, pumped into the vehicle's tank, and finally used to run a fuel-cell stack whose output is water and ... electricity.

Renewable hydrogen requirement

The stations funded by the California Energy Commission are required to dispense hydrogen that is at least 33 percent renewable, under an Addendum to the terms of the funding contracts it signs with private providers like First Element Fuel.

2015 Hyundai Tucson Fuel Cell at hydrogen fueling station, Fountain Valley, CA

2015 Hyundai Tucson Fuel Cell at hydrogen fueling station, Fountain Valley, CA

That gets the wells-to-wheels carbon footprint of a hydrogen vehicle below that of gasoline vehicles, on average, despite the other two-thirds being mostly sourced today from natural gas, a fossil fuel.

"All applicants ... must provide a plan for dispensing at least 33% renewable hydrogen," says the CEC's contract language.

"This plan must describe how each station or portfolio of stations in the application expects to dispense at least 33 percent renewable hydrogen on a per kilogram basis over the applicant’s portfolio of Energy Commission-funded stations."

Eligible feedstocks include biomethane or other biogases, including biomass, digester gas, landfill gas, sewer gas, or municipal solid waste gas.

Eligible energy sources to crack hydrogen out of those feedstocks include electricity from:

  • Fuel cells using renewable fuels
  • Geothermal
  • Small hydroelectric (30 megawatts or less)
  • Ocean wave
  • Ocean thermal
  • Tidal current
  • Photovoltaic solar panels
  • Solar Thermal
  • Wind
  • Biomass digester gas
  • Municipal solid waste conversion (non-combustion thermal process)
  • Landfill gas
  • Renewable Energy Certificates (RECs)

Separate Senate bill

The commission notes that this requirement is independent of a mandate in a Senate bill (SB1505) that permits the California Air Resources board to regulate the renewable content of hydrogen fuel.

That bill puts two mandates on hydrogen dispensed for use in fuel-cell vehicles.

2015 Hyundai Tucson Fuel Cell at hydrogen fueling station, Fountain Valley, CA

2015 Hyundai Tucson Fuel Cell at hydrogen fueling station, Fountain Valley, CA

First, the wells-to-wheels greenhouse-gas emissions must be (at least) 30 percent below the average emissions for gasoline.

Second, all hydrogen produced for fuel-cell vehicles must be made from at least one-third renewable energy resources.

There are, however, exceptions to the requirement. Among them are the following:

If the state board determines that there is insufficient availability of hydrogen fuel from eligible renewable resources to meet the 33.3 percent requirement of this paragraph, the state board may, after at least one public workshop and on a one-time basis, reduce the requirement by an amount, not to exceed 10 percentage points, that the state board determines is necessary to result in a renewable percentage requirement for hydrogen fuel that is achievable.


If the executive officer of the state board determines that it is not feasible for a public transit operator to use hydrogen fuel made from eligible renewable resources, the executive officer may exempt the operator from the requirements of this paragraph for a period of not more than five years and may extend the exemption for up to five additional years.

2015 Hyundai Tucson Fuel Cell at Hyundai headquarters, Fountain Valley, CA

2015 Hyundai Tucson Fuel Cell at Hyundai headquarters, Fountain Valley, CA

State-funded stations only

Today, the SB1505 requirements are enforceable only for stations funded by California, given the early state of the hydrogen vehicle market.

At least in theory, once the state-funded stations have paved the way for hydrogen-powered vehicles to launch in the state, privately-funded fueling infrastructure will follow.

But privately funded stations will not be required to meet the same specifications until a total of 3.5 million kilograms of hydrogen has been sold in California.

Using the Toyota Mirai metric of 312 miles of range from 5 kg of hydrogen fuel, that amount would translate to roughly 200 million miles covered by fuel-cell vehicles before the renewable rule kicks in for private hydrogen stations.

According to CARB's 2015 Annual Evaluation of FCEV Deployment and Hydrogen Fuel Station Network Development report (often called the “June AB 8 report"), that trigger will be reached in 2018.

Compliance with renewable hydrogen mandate, June 2015 [California Air Resources Board]

Compliance with renewable hydrogen mandate, June 2015 [California Air Resources Board]

So far, so good

As to the renewable content of the hydrogen fuel coming online this year, the report says:

The statewide renewable hydrogen content is essentially the same as in the previous report, expected to be 45 percent when all funded stations are built.

Small corrections in data and changes to a limited number of stations have occurred since the previous reported value of 46 percent. State funded stations significantly exceed the minimum requirement for renewable energy resource utilization.

Moreover, the historical trend also shows renewable resource utilization for hydrogen has always exceeded the requirement. The minimum renewable content was 38 percent in 2010, peaked at 52 percent in 2012, and will be 47 percent at the end of 2015.

Small duration peaks and valleys from one year to the next, especially for projected stations, are only a matter of the timing of individual stations’ operational date projections and are not indicative of the general trend over many years.

Hyundai Tucson Fuel Cell leased by Jenny Ma + Clayton Crawley, Vancouver, BC, Canada

Hyundai Tucson Fuel Cell leased by Jenny Ma + Clayton Crawley, Vancouver, BC, Canada

Readiness a 'challenge'

The report, incidentally, also contains a single paragraph under the heading, "Station Availability, Maintenance Readiness, and Online Status."

That paragraph says, in its entirety:

Current FCEV customers too often experience stations being unavailable due to equipment malfunction or other issues, and clear communication of station status remains a challenge. Improved status reporting, more reliable backup fueling capability that will be afforded by the mobile fueler, and full time dedicated personnel to react to station malfunctions are needed to improve the convenience and FCEV driver satisfaction with the hydrogen fueling station network.

The experience of the first 70 drivers of Hyundai Tucson Fuel Cell vehicles in Southern California, which have now been available for lease since June 2014, would certainly support that assessment.

The stations they have been using, it turns out, were all "experimental" or "limited" in function, as compared to the more robust and permanent stations being funded by the state.

As of this month, two fully-configured hydrogen stations have been completed and another eight are now under construction. By the end of this year, Toyota expects 10 to 15 stations to be "open and ready," it said last month.

In April 2013, the California Fuel Cell Partnership said its goals were to have roughly three dozen operating by the end of this year, 70 by 2016, and 100 by 2020. Those 70 stations will supply enough hydrogen for up to 30,000 fuel-cell vehicles, it said.


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