UC Irvine

For California and other parts of the world to move towards a net-zero-emission grid, potentially a 100% renewable grid, complementary technologies to support renewable solar and wind integration need to be clearly established. Specifically, the integration of variable and intermittent solar and wind renewable generation requires resources that can respond dynamically to changes in the net load in order to ensure stable grid performance. Zero-emission vehicles (ZEVs), encompassing battery electric vehicles (BEVs) and fuel cell electric vehicles (FCEVs), are uniquely positioned to (1) support variable renewable generation and provide benefits to the grid while, at the same time (2) reducing emissions from the transportation sector. Due to their disproportionately large contribution to air pollution and greenhouse gas (GHG) emissions, targeting heavy-duty vehicles (HDVs) is essential if reduction goals are to be met. This work assesses the feasibility of heavy duty ZEVs (HD-ZEVs), selecting California as the example. From a technical standpoint, more than half of Class 3-7 vehicle miles travelled (VMT) can be met with heavy-duty BEV product in development today without trip modification. Class 8 trucks have a much lower BEV feasibility due to their longer trip distances and heavy-duty FCEV product becomes more likely. The challenge becomes providing carbon-free fuel, namely renewable electricity for HD-BEVs, and renewable hydrogen for HD-FCEVs. This study assesses the fuel supply chain impact of HD-ZEV deployment on GHG emissions and air quality for the year 2050. HD-BEVs relying on uncoordinated charging can increase peak load demand and hinder the target of achieving zero GHG emissions from the electric grid. Intelligent charging of HD- BEVs and renewable hydrogen production for HD-FCEVs are both effective methods for utilizing otherwise curtailed renewable generation for the support of a zero or near-zero emissions electric grid. This study also finds that moving towards an 80% reduction in GHG emissions from HDVs through ZEV adoption has the co-benefit of significantly reducing ozone and PM2.5 concentrations in key regions of California. In comparison, reducing grid emissions from an 80% reduction to a 100% clean electric grid has a significantly smaller, but not trivial, impact in criteria air pollutant concentrations.