A study by North Carolina State University performed a comprehensive examination of the environmental life cycle impacts of shared e-scooters.
Nationwide, United States
Are e-scooters polluters? The environmental impacts of shared dockless electric scooters
Summary Information
Researchers from North Carolina State University gathered data and statistically modeled the life-cycle environmental impact associated with the materials, manufacturing, transportation, charging, and end-of-life for shared dockless standing e-scooters.
Researchers gathered data from range of sources, including the actual disassembly of an electric scooter to inventory all the materials used in the scooter. They also gathered data from various US Environmental Protection Agency (EPA) sources and some data from e-scooter companies themselves.
Researchers then conducted a full lifecycle environmental analysis. They accounted for all the carbon emissions of a single e-scooter from the production of the raw materials to its manufacturing to its usage and finally to its disposal. They conducted a Monte Carlo analysis to account for "inherent variability and uncertainty" in some of the assumptions in the analysis. Finally, they compared their findings to other modes of transportation that might commonly substitute for e-scooter usage like walking and biking.
Findings:
- Under "Base Case" or default parameters e-scooters were found to have a lifecycle environmental impact of 202 grams of Carbon-dioxide (CO2) per passenger mile traveled. Surprisingly, electricity needed for charging only accounted for 4.7 percent of total carbon emissions. Half of the total emissions came from the materials and 43 percent came from load balancing activities associated with running e-scooter operations.
- Environmental impacts of e-scooters were found to be higher than electric mopeds, buses with high ridership, electric and normal bicycles. Emissions were lower than a personal automobile and dockless bicycles.
- Relative to emissions from charging in Raleigh, charging with a 0 kg CO2/kWh power source (to approximate wind, solar, or nuclear) would decrease life cycle emissions by six percent, while charging with a 1 kg CO2/kWh power source (to approximate coal generation) would increase life cycle emission
- Reducing the average driving distance for collection and distribution to 0.6 miles per scooter reduced the average life cycle global warming impacts by 27 percent, while the exclusive use of fuel-efficient vehicles for collection resulted in a 12 percent reduction
- Limiting scooters collection to those with a low battery state of charge would require a change in policy to allow scooters to remain in public spaces overnight, but could yield a net reduction in global warming impacts of 19 percent.
