Electric Vehicles (EVs)

About Technologies

How EVs Work


Mouse over the image to see the key parts of a battery electric vehicle (BEV, or EV). Graphic courtesy of the National Renewable Energy Lab, U.S. DOE

 

Electric vehicles (EVs), also called battery electric vehicles (BEVs), are propelled by an electric motor (or motors) powered by rechargeable battery packs. No other fuel source is used, and there is no internal combustion engine (ICE). EVs require battery charging to power the motor.

Electric vehicle benefits

  • Energy-efficient driving. Electric motors convert 75% of the chemical energy from the batteries to power the wheels, while ICEs only convert 20% of the energy stored in gasoline.
  • Environmentally friendly driving. EVs emit no tailpipe pollutants, although the power plant producing the electricity may emit carbon dioxide or other GHGs. Electricity from nuclear-, hydro-, solar-, or wind-powered plants creates no air pollutants.
  • Performance benefits. Electric motors provide quiet, smooth operation and stronger acceleration while requiring less maintenance than ICEs.
  • Reduced dependence on imported energy. Electricity is a domestic energy source in many countries, as opposed to oil.

Electric vehicle challenges

  • Driving range. Most EVs can only go about 100–200 miles before recharging, while gasoline vehicles can go over 300 miles before refueling.
  • Charge time. Fully charging the battery pack can take 4 to 8 hours. Even a "quick charge" to 80% capacity can take 30 minutes.
  • Battery cost. The large battery packs are expensive and may need to be replaced one or more times before the rest of the car.
  • Bulk and weight. Battery packs are heavy and take up considerable vehicle space.

However, researchers are working on improved battery technologies to increase driving range and decrease charging time, weight, and cost. These factors will ultimately determine the future of EVs.

IA-HEV Work on EVs

IA-HEV Tasks have been collecting significant data on EVs that is valuable in assessing their status and laying the foundation for continued improvements. Task 17, Systems Integration for EVs, is analyzing technology options for the optimization of EV components and drivetrain configurations that will enhance vehicle energy efficiency performance. Task 18, EV Ecosystems, is investigating how to integrate EVs into cities, a follow-on of the studies of the successes and failures of past rollouts of EVs conducted in Task 14, Market Deployment of Electric Vehicles: Lessons Learned. Task 19, Life Cycle Assessment of EVs, is exploring sustainability in the manufacture, recycling, and end-of-life treatment of EVs, and Task 20, Quick Charging, will discuss the impacts upon the vehicle of quick-charging technologies among its topics.