Transportation – the movement of people and goods – is a large energy consumer. According to the US Energy Information Administration (EIA), as much as 28% of all the energy consumed annually in the US is for transportation, and most of that energy is delivered from petroleum-based fuels like gasoline and diesel. As a result, total greenhouse gas emissions from the transportation sector have reached parity with or even surpassed the emissions associated with electricity generation.
Any effort to substantially reduce overall regional greenhouse gas emissions must address the transportation sector. Electrification of transport options that displace petrol-based vehicles and utilize the region’s clean hydro-electric, wind, and solar power is an effective approach. Electrification may be accomplished directly through the use of plug-in battery electric powertrains or indirectly by using fuel cell technology with hydrogen supplied through electrolysis or other green methods.
For the 2021 Power Plan, we developed a model of transportation and the related fuel usage and emissions, with an emphasis on the roadway mode:
- Light-duty vehicles, which are passenger cars, light trucks and vans
- Buses – public transit and school
- Heavy-duty vehicles which are light commercial trucks, and medium and large freight trucks
The focus of the work was to provide a forecast of electricity demand from the transportation sector for power planning, but also to gain insights into how electrification of vehicles – both direct plug-in and indirect fuel cell – might impact regional emissions
Electric vehicles are poised to disrupt the automobile and oil business models, especially in the light- duty vehicle space. In many cases, electric vehicles provide lower ownership costs (especially fuel costs), require less maintenance, and produce much fewer emissions than traditional gasoline powered vehicles. See the Vehicle Calculator section for further reading.
Forecasting the future sales, stock and demand of electric vehicles is challenging due to the relatively short history of electric versions in the marketplace. Consumers may choose a vehicle based on preferences other than ownerships costs, for instance vehicle carrying capacity or driving range. The electric vehicle offerings in the market to date have been fairly limited, but in the next few years many more models will be introduced in a variety of sizes, with many having longer range capabilities. As more electric models are made available and charging infrastructure is added, especially along travel corridors, electric vehicle purchases could really accelerate. Therefore, the transportation sector may place significantly more load on the electricity system by the end of the power planning time horizon than it does currently.
There are three main pieces to our transportation work for the 2021 Power Plan. The first involves the creation of hourly time-series load profiles for plug-in electric vehicles and buses. The derivation of the profiles is discussed in detail in the Plug-in Load Profiles section.
The second piece defines the requirements for hydrogen as an energy carrier for heavy duty freight vehicles powered by fuel cell technology. Heavy duty vehicles, such as large freight trucks are more challenging to electrify using plug-in battery technology due to issues around battery weight and limited range. Fuel cell vehicle technology powered by hydrogen may provide a viable zero emission (tailpipe) alternative for moving freight. Trucking could be electrified either way, right now it’s not clear which technology will win out. The use and production of hydrogen as a zero or low emission energy source for transportation is discussed in the Hydrogen & Fuel Cells Section.
The third piece of our work is the development of a model of the roadway transportation sector that includes all fuels – gasoline, diesel, natural gas, electricity, and fuel cell hydrogen. This model was used to produce a reference forecast, along with two other cases – a high plug-in battery electric case and a hydrogen fuel cell case. A brief description of the model can be found here. The key findings from all three cases are summarized in the Model Findings section, and more detailed results are available in Model Reference Case section, the Model High Electric Case section, and the Model H2E Case section.