

Cadmus supported the Colorado Energy Office in a major new study on life-cycle emissions and costs of school buses, transit buses, refuse trucks, and short and long-haul trucks. Led by Cadmus experts in partnership with Argonne National Laboratory, the study was required by Colorado statute prior to enactment of a medium- and heavy-duty vehicle tax credit in the state.
Using a tool developed by Argonne National Laboratory, Cadmus experts estimated emissions, the total cost of ownership, payback period, and marginal damage costs for various alternative and conventional fuel technologies. The vehicle technologies that Cadmus considered in the study include electricity, hydrogen, natural gas, propane, hydraulic hybrids, diesel, and gasoline.
Key insights include:
- When all social and economic costs and benefits are summed together, electric vehicles, hydrogen fuel cell vehicles, and vehicles running on renewable natural gas offer – by far – the largest net benefits to Colorado compared to diesel alternatives.
- Certain fuels are still more expensive per mile than gasoline and diesel but save money when factoring in all savings from health benefits, agriculture, and recreation.
- Compressed natural gas, liquefied natural gas, and liquefied petroleum gas have much higher life-cycle carbon monoxide (CO) emissions than diesel and lower nitrogen oxide (NOx) emissions than diesel.
The study also examines how emissions will change over time for electric vehicles powered by electricity from Xcel Energy, the largest utility in Colorado. In 2017, Xcel Energy’s energy mix was largely coal, natural gas and wind. Xcel Energy’s Colorado Clean Energy Plan portfolio will grow wind and solar generation and retire coal generation through 2027. As renewable penetration in Xcel Energy’s grid mix increases between 2017 and 2027, emissions per mile of electric vehicles powered by the utility decline for all air pollutants.
“Colorado is quickly emerging as a leading state in sustainable transportation policy. This study lays the groundwork for reducing emissions in one of the toughest sectors: medium- and heavy-duty vehicles. Using our analysis as justification, the State enacted its alternative fuel tax credit, which will help clean the air for years to come,” said the lead author, Dr. Geoff Morrison.
The study can be found here.