The Case for Electric Vehicles
Of all the human-source greenhouse gas emissions in the US, approximately 28% come from the transportation sector. Passenger cars and light-duty trucks accounting for more than half of those emissions.
The average passenger vehicle travelling 10,000 per year emits about 4.6 metric tons of carbon dioxide each year. With over 250 Million vehicles registered on US roads (including passenger cars, motorcycles, trucks, buses, and other vehicles), it is easy to see why the transportation sector accounts for such a large percentage of US greenhouse gas emissions.
What is an Electric Vehicle?
All-electric vehicles (EVs) run on electricity only. They are propelled by one or more electric motors powered by rechargeable battery packs. They are charged using grid electricity just like your phone or laptop.
Pros for EVs:
- Energy efficient – EVs convert more than 77% of the grid electrical energy to driving power. Conventional gasoline vehicles only convert 12% to 30% of the energy stored in gasoline to driving power.
- Environmentally friendly – EVs do not emit tailpipe pollutants. However, greenhouse gases may be emitted by the power plant producing the electricity. EVs can reduce emissions of greenhouse gases even further if the electricity used for charging is produced by renewable energy.
- Performance benefits – Electric motors provide quiet and smooth operation, provide stronger acceleration, and require less maintenance than internal combustion engines.
- Reduced energy dependence – Electricity is a domestic energy source, unlike most gasoline.
Limitations of EVs
- Driving range – Range is typically more than 100 miles on a full charge. However, range is constantly increasing and some models are able to go 200 to 300+ miles.
- Recharge time – Fully recharging the battery pack can take 3 to 12 hours on a level-2 charger (depending on battery capacity and charger power).
- Battery life limitations – Batteries for EVs are expensive. But they are also designed for extended life. A study by DOE’s National Renewable Energy Laboratory suggest these batteries may last 12 to 15 years in moderate climates and 8 to 12 years in severe climates.