Available clean fuels for the state of Washington could meet a 2028 target of 11.2% reduction in average carbon intensity by 2028, according to an analysis completed by independent research firm Cerulogy and commissioned by the Union of Concerned Scientists (UCS).

The largest fuel pathways used to meet this target include electricity, lower carbon sources of ethanol blended into gasoline, biodiesel and renewable diesel. Biomethane and renewable aviation fuel also contribute.

Carbon savings against baseline delivered in Steady Progress scenario.

Although the analysis only projects fuel availability out to 2030, the result are consistent with a reduction in carbon intensity of 20% by 2035.

The research was conducted by Chris Malins, who has a doctorate in applied mathematics from the University of Sheffield, was formerly Fuels Program Lead at the International Council on Clean Transportation (ICCT) and is an independent global expert on low carbon and clean fuels policy.

Malins presented four scenarios: Steady Progress; Accelerated Progress; High EV; and Delayed EV.

• The Steady Progress scenario assumes that in the early years of the program the largest carbon savings are delivered by first generation biofuels, while in later years the expected growth in the fleet of battery electric and plug-in hybrid vehicles in Washington increases the consumption of electricity for road transportation, and given the large proportion of renewable energy in the Washington State electricity supply delivers considerable carbon savings.

  The modelling also assumes more modest increases in the supply of alternatives to diesel fuel—biodiesel, renewable diesel and renewable natural gas for trucks. In 2028, an 11% carbon reduction is delivered compared to the baseline.

• In the more aggressive Accelerated Progress scenario, marginal increases in the deployment and carbon performance of biodiesel, ethanol and renewable natural gas, plus additional credits from the use of renewable natural gas at the refinery, result in even larger emissions reductions: 13.1% by 2028.

• The other two scenarios presented consider cases with more and less rapid increases in sales of electric vehicles in Washington State.

The four scenarios presented demonstrate that given moderate increases in alternative fuel supply and continued growth in electric vehicle sales, compliance could be readily achieved with a 10% carbon intensity reduction target for 2028 under a Clean Fuels Program for Washington State. The increasing size of the electric vehicle fleet makes total credit generation quite sensitive to assumptions about the rate of sales growth, and therefore it may be appropriate for a Washington State Clean Fuels Program to include a degree of flexibility for the administrator to adjust the stringency of requirements in response to realized electric vehicle sales.

—“Washington’s Clean Fuel Future”

The Washington state legislature is expected soon to consider a bill modeled on last year’s House Bill 2338 that would require petroleum refineries and fuel importers to reduce the average carbon intensity of the fuels they sell in Washington by 10% of 2017 levels by 2028.

Similar programs exist in California and Oregon. Refineries and fuel importers could reduce carbon intensity by either blending low-carbon biofuels into the gasoline or diesel they sell, or by purchasing credits generated by providers of lower-carbon fuels, including electricity, renewable diesel and renewable natural gas.

Transportation is the largest source of carbon emissions in Washington. The state needs to cut emissions by nearly 16 million metric tons per year to meet its 2035 carbon emissions limit. Washington is not on track to meet this goal. Governor Jay Inslee’s administration says the proposed clean fuels program would achieve nearly half of the emissions reductions needed in the transportation sector.

Washington generates 60% of its electricity from renewable sources, mostly from hydropower.

A clean fuels program would have the added benefit of generating credits that can put more electric vehicles on the road. If credits were used to fund a statewide rebate program, rebates could total $2,000 or more per car, according to the analysis. In 2017, there were 7,000 electric vehicles sold in the state.