California surpassed its 2020 greenhouse gas reduction target ahead of schedule, driven largely by improvements in the electricity sector. However, emissions from transportation, which account for 37% of the state’s total, rose by 0.76% from 2013 to 2017. Efforts to reverse this trend encompass a shift from petroleum-based fuels to lower carbon alternatives, including vehicles fueled powered by electricity, hydrogen, or/and renewable biofuels. These alternatives also help reduce smog-forming pollutants that pose a health risk to Californians.
Featured Research Topics
Electric vehicles (EVs) are a growing source of electricity demand in California. Increasing deployment of EVs creates both challenges and opportunities for the electric system. Managing when, where, and how quickly EVs charge—and in some cases discharge—and aggregating the load of many vehicles simultaneously can reduce system-wide costs for ratepayers, help integrate more intermittent renewable electricity, and create financial savings for EV drivers.
A CEC-funded project is pioneering vehicle-to-building and vehicle-to-grid technologies on at UC San Diego that share the energy stored in electric vehicle batteries with the campus microgrid when not needed by drivers.
Advanced EV Battery Technologies
Lithium-ion batteries used to power EVs have inherent limitations that curtail travel distances per charge. They also require safety features to prevent flammable organic solvents from igniting or exploding. Improvements in the performance and safety of batteries are needed to enable broader adoption of EVs. Lithium metal batteries, which can hold more power per pound than the current generation of lithium-ion batteries, have the potential to achieve increased mileage ranges safely and cost-effectively. A CEC-funded project supports the manufacturing scale-up of a battery that uses lithium metal anodes and a nonflammable electrolyte.
Low-emission Medium- and Heavy-duty Vehicles
Medium and heavy-duty vehicles are critical to California’s economy, yet they contribute significantly to greenhouse gas and criteria pollutant emissions, especially in heavily trafficked freight corridors and around the state’s major ports. Advancing vehicle and infrastructure technologies that use cleaner fuels such as renewable natural gas, hydrogen, and electricity to meet industry performance demands will help transition California's truck and bus fleets to lower emission alternatives. A CEC-funded project is developing and demonstrating a plug-in hybrid-electric drayage truck that can efficiently run on either zero-emission electricity for shorter urban routes or low-emission natural gas for longer highway routes.
Low-Carbon Renewable Fuels
In California, petroleum-based fuels used for the transportation sector contribute to the largest source of carbon emissions. Low-carbon fuels can lower greenhouse gas and criteria pollutant emissions, such renewable diesel, renewable jet-fuel, and renewable natural gas, are vital for California to meet climate change and air quality mandates. Renewable fuels can be produced from various California waste feedstocks using advanced thermochemical technologies and blended into conventional fuels, reducing overall carbon intensity. A CEC-funded project is demonstrating the commercial viability of a biomass conversation technology that will efficiently and cost-effectively transform agricultural and hardwood waste feedstocks into a low-carbon bio-oil that can be upgraded to renewable diesel or jet fuel.
As California progresses towards its Zero Emission Vehicle goals, large volumes of battery waste will need to be processed in the coming years. EV batteries are typically retired with 70-80 percent of their original capacity, at which point they are often still capable of performing useful services other than powering EVs. This presents a significant opportunity to rebuild them for stationary applications, in turn helping to efficiently manage waste and reduce the need for newly mined materials. However, several uncertainties need to be resolved regarding whether repurposed batteries can serve as a cost-effective alternative for new stationary systems, how to safely combine modules from different suppliers, and their degradation characteristics. CEC-funded projects are supporting innovative approaches to repurposing EV batteries for stationary storage and validating whether they can cost-effectively integrate resilient, behind-the-meter renewable energy systems at small-to-medium-sized commercial buildings.