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Because residential charging is convenient and inexpensive, most plug-in electric vehicle (also known as electric cars or EVs) drivers do more than 80% of their charging at home. Charging in a single-family home, usually in a garage, allows you to take advantage of low, stable residential electricity rates. The cost to run your car over the course of a year can be less than running an air conditioner. Charging at a multi-family residential complex, like a condo or apartment, is possible, but can be complex and more similar to public charging.
Costs to Charge at Home
Fuel costs for EVs are lower than for conventional vehicles. Based on the national average of 12.6 cents/kwh, fully charging an all-electric vehicle with a 100 mile range and depleted battery would only cost about the same as operating an average central air conditioner for six hours. Because plug-in hybrid electric vehicles have smaller batteries, each individual charge costs even less. General Motors estimates the annual energy use of a Chevy Volt is 2,520 kWh, which is less than required for a typical water heater. In comparison, over the past ten years, U.S. regular conventional retail gasoline prices have fluctuated from below $1.50 to over $4, squeezing annual household budgets by as much as $1,500 per average passenger car. If you charge primarily at night and your utility offers special off-peak rates, your costs may be even lower. Find out if your utility offers any special incentives for EV owners.
Equipment to Charge at Home
Home charging can use either the relatively simple Level 1 electric vehicle supply equipment (EVSE) or the slightly more complex Level 2 EVSE. Charging with Level 2 EVSE is faster and can be more convenient, but requires special equipment that is more expensive to install than Level 1. For both types of EVSE, you should store the charging cord securely so it is not damaged, check the accessible EVSE parts periodically for wear, and keep the system clean.
You should consult EV manufacturer guidance for information about the required charging equipment and understand the specifications before purchasing equipment and electric services. In general, check with your utility and a trusted electrical contractor—and get cost estimates—before installing EVSE or modifying your electrical system.
Level 1 EVSE
Level 1 EVSE provides charging through a 120 volt (V) AC plug. Level 1 adds about 2 to 5 miles of range to a vehicle per hour of charging time, making it suitable for plug-in hybrid electric vehicles and depending on your circumstance, even some all-electric vehicles.
Charging with Level 1 EVSE will not require any special equipment besides an outlet, but does require a dedicated branch circuit. Before plugging an EV into any outlet, be sure that the circuit does not supply other appliances such as refrigerators or lights. For the connector, nearly all EVs come with a portable Level 1 EVSE cordset, which has a standard three-prong household plug on one end for the outlet and a standard J1772 connector for the vehicle.
Level 2 EVSE
Level 2 EVSE provides charging through a 240 V AC plug. Level 2 adds about 10 to 60 miles of range to a vehicle per hour of charging time, making it suitable for all EVs.
Using Level 2 EVSE requires drivers install special charging equipment as well as have a dedicated electrical circuit of 20 to 100 amps. Fortunately, most houses already have 240 V service for appliances such as clothes dryers and electric ranges. The price of Level 2 residential EVSE varies, but typically ranges from $500 to $2,000 before installation and state or utility incentives. Learn if your state or utility offers incentives for EVSE.
For homes with adequate electrical service, installation is usually relatively inexpensive. However, it can be substantial if an electrical service upgrade is required. As EVSE installations must comply with local, state, and national codes and regulations, be sure to work with a licensed electrical contractor. In addition to the National Fire Code, your local building, fire, environmental, and electrical inspecting and permitting authorities may also require permits. In many areas, installers must submit a site installation plan to the permitting authority for approval before installation. Your contractor should know the relevant codes and standards and should check with the local planning department before installing EVSE. In general, check with your utility and a trusted electrical contractor—and get cost estimates—before installing EVSE or modifying your electrical system.
The safety risks of installing and using home EVSE are very low, similar to those associated with other large appliances like clothes dryers. Residential EVSE are generally installed in garages, but homeowners can also purchase outdoor-rated EVSE built to withstand weather and other types of stresses. EVSE cords are built to withstand some abuse—even being run over by a car—and the power flow through the cord is cut off when the vehicle is not charging.
The EVSE wall unit should be protected from contact with the vehicle, such as with a wheel-stop. The EVSE wall unit also should be positioned to minimize the hazard of tripping over the power cord. In general, this means keeping the cord out of walking areas and positioning the wall unit as close as possible to the vehicle’s electrical inlet. Another option is to install an overhead support that keeps the cord off the floor.
There is a variety of equipment for Level 2 EVSE available, ranging from simple models with standard safety features and status lights to more advanced products have features with enhanced displays, charging timers, smartphone connections, and keypads. There are a number of options available for residential charging infrastructure, and your EV manufacturer should be able to recommend which Level 2 EVSE might work best with your vehicle. No matter which product you choose, your EVSE should be certified for EV use by a nationally recognized testing laboratory (such as Underwriters Laboratory). For more information on available residential EVSE, see Plug-In America’s Accessory Tracker webpage.
Charging in Multi-Unit Dwellings
EV charging stations for multi-unit dwellings, such as condos or apartments, provide owners with a unique way to help attract and retain residents and foster an environmentally sustainable community. However, both building owners and EV drivers face unique considerations when installing charging stations, ranging from parking and electrical service access to billing and legal concerns. Learn how to work with your building owner to install a station through the California Plug-in Electric Vehicle Collaborative’s Guide for Residents of Multi-Unit Dwellings. The Alternative Fuels Data Center also has best practices and case studies to share with owners of multi-unit dwellings.