Electricity can be used to power all-electric vehicles (EVs) and plug-in hybrid electric vehicles (PHEV’s) directly from the power grid using battery storage, or from electricity generated on-board through fuel cells (see hydrogen fuel cells). Electric vehicles were developed in Europe over a century ago, and in 1899 were the most popular vehicle type sold in the United States. Production peaked in 1912, and since petroleum powered vehicles have dominated the auto market. However, when air quality and energy independence emerged as top priorities at the turn of the 21st century, electric vehicle propulsion has been gaining popularity.
Electricity can be produced from a variety of energy sources, including oil, coal, nuclear energy, moving water, natural gas, wind energy, and solar energy. Most of the electricity in the United States is produced by steam turbine generators at power plants from coal (42%), natural gas (25%), nuclear energy (19 %), and to a much lesser degree petroleum (1%). Electricity is also produced from renewable sources, including hydropower, biomass, wind, geothermal, and solar power (13%) (Energy Information Administration, 2011 data).
The electrical transmission grid in the United States consists of nearly 160,000 miles of high-voltage transmission lines that link consumers with electrical generation plants. EVs and PHEVs are a new source of demand for electricity, leading to concerns of over taxing the grid. However, according to a study by Pacific Northwest National Laboratory, 73% of the light-duty vehicles in the United States could be powered by electricity before there would be a need for new electricity-generation capacity or substantial upgrades to the grid. Additionally, if a majority of EVs and PHEVs charge during off-peak times, when the electric load on the system is at a minimum, the draw on the current system would be further mitigated.
Meanwhile, significant research and development resources are going into modernizing the current transmission and distribution infrastructure with “smart grid” technologies: computer-based remote control and automation technologies that will allow for more efficient delivery of electricity. Greater efficiency of this colossal network will equate to increases in reliability, affordability, global competitiveness, ability to accommodate renewable energy sources, and the potential to decrease our carbon footprint as the population continues to grow. Additionally, the concerns raised by significant vehicle charging will be addressed by the introduction and growth of this “smart” network.
A majority of electric vehicle charging will take place at the vehicles “home base” – residential locations and fleet facilities. In addition to home charging, public charging networks are developing throughout the country, creating convenient charging options and reducing range concerns. Recommended charging locations include: shopping centers, city parking lots and garages, airports, hotels, government offices, and other businesses. Electric vehicle supply equipment (EVSE) installations must comply with local, state, and national codes and regulations. Appropriate permits may be required from the local building, fire, environmental, and electrical inspecting and permitting authorities. Available charging options include:
Level 1: delivers electricity through a 120 volt AC electrical outlet, and can be accomplished almost anywhere. Most EVs come with a Level 1 charging cord so that no additional equipment purchases are required, and many EV and PHEV owners will be able to meet their daily driving range requirements by charging overnight with Level 1 EVSE requiring no additional cost or installation. This form of charging typically adds 2 to 5 miles of driving range per hour of charging.
Level 2: delivers electricity through a 240 volt (residential) or 208 volt (commercial) electrical outlet - most homes have 240 V service available. This typically requires extra installation for the increased voltage outlet, and a dedicated 20 to 80 amp circuit. Level 2 EVSE adds about 10 to 20 miles of range per hour of charging time, depending on the vehicle, and can easily charge a typical EV battery overnight.
DC Fast Charging: delivers the equivalent of 480 volts and enables an EV to fully charge in approximately 30 minutes. Unlike Level 1 and Level 2 charging, which converts the electricity from AC to DC before delivering it to the vehicle, DC Fast Charging delivers DC electricity directly to the vehicle battery. DC Fast Charging stations are typically located along heavy traffic corridors and add approximately 60 to 80 miles of driving range in 20 minutes.
Electric Vehicles reduce our dependence on foreign petroleum through the use of domestically produced electricity (EVs & PHEVs) and greater fuel economy (PHEVs & HEVs). They also have notable emissions benefits. However, due to regional variations in electricity production, lifecycle emissions benefits are dependent on your location - use the Vehicle Cost Calculator to compare life cycle emissions of individual vehicle models in a given location. Additionally, electric vehicle owners enjoy a significant fuel savings, which offsets slightly higher purchase price. Electric Vehicles also provide a great opportunity to use small-scale renewables, like solar panels, to provide clean energy for vehicles and reduce demand on distribution infrastructure by generating electricity near the point of use. There are still challenges and concerns regarding battery costs, battery components, and vehicle range, but extensive research and development is working to address these issues.