Overview of EV Charging

Desriptions follow for three types of charging locations for plug-in electric cars – home, business / workplace, and public venues; together these comprise the EV charging infrastructure in its early stages. This section also highlights national initiatives under way and the REVI utilities’ local infrastructure efforts.

EPRI’s Estimated Charging Times

  • 8 hours for a 120volt 15amp circuit
  • 3-6 hours for a 240volt circuit
  • 15-30 minutes @ 80% charge for DC fast charging

Charging times will vary by EV type / model

Types of Charging Locations: Home, Business, Public

EV drivers want to recharge where they live, where they work and at charging stations available for public use in surrounding areas. Studies show that the existing electric system can accommodate the addition of EV load near-term. Utilities can address localized impacts as part of ongoing distribution system maintenance and, to avoid peak conditions, customers are encouraged to plug-in during off-peak periods.

Home Charging

Industry research indicates that up to 80% of all EV charging will be done at the driver’s place of residence – most likely while the car is parked overnight (ideally, in a fixed location). The charging location will be equipped with a 120-volt standard wall outlet (“Level 1” charging) and/or an optional 240-volt Electric Vehicle Supply Equipment (EVSE for ”Level 2” charging). Preferences may be based on costs (equipment and installation), daily driving range and the type of EV purchased. For example, drivers of the plug-in hybrid Chevy Volt may decide to get by with Level 1 charging, while drivers of the all-electric Nissan Leaf opt for Level 2 to reduce recharging time by roughly half. Home EVSE units can be arranged through the EV dealership and require proper installation by a licensed electrician with the necessary local permit for wiring upgrades.

There’s an interesting opportunity and synergy with offpeak charging: drivers plug-in while EVs are parked overnight, there’s unused capacity in the electric system during these hours and, in some regions, offpeak generation resources have environmental advantages compared to on-peak generation. To get EV owners in the habit of overnight charging, some utilities may offer time-of-use electric rates with special cost savings or metering requirements. Programs will vary by state and jurisdiction.

One yet-to-be-solved challenge is home charging at multi-family dwellings, including condominium complexes, high-rise apartments and areas without assigned parking spots.

Business / Workplace Charging

This category includes retail establishments and other businesses that offer EV charging services as a means of drawing traffic to their locations – for example, shopping malls, downtown parking garages, entertainment and sports venues, restaurants and more. Workplace charging is offered by companies that want to encourage EV ownership among employees and allow them to plug in to recharge (or top off) their batteries for the commute home. Major employers with environmental sustainability programs are leading by example and adding EVs to their fleet purchases and shared-lease plans.

EV charging availability at workplace and business venues continues to evolve. Drivers can expect an expanding array of free, low-cost and premium-priced custom service options.

Public Charging

The role and availability of public charging – sometimes referred to as convenience charging – will vary significantly by geography. Markets designated for federally-funded Level 2 charging stations are testing the theory that early infrastructure can help jump start the EV market and overcome “range anxiety” for potential buyers. Another factor is time since fully recharging an EV takes several hours. “DC fast charging” equipment (powered by direct current for 15-30 minute charges) is being introduced to serve select high-traffic locations, for example along interstate highways. This technology may be cost-prohibitive for widespread deployment and it’s currently undergoing technical study by utilities and other standards groups.

How Much Infrastructure?

Realistically, the optimal charging infrastructure is one that’s appropriately sized for the local EV population. Based on current vehicle production forecasts, that number may be relatively small in the northeast U.S. for the immediate future. An exciting aspect of EV charging infrastructure is the emergence of supporting technologies and “telematics.” Smartphone applications can provide customer-friendly systems to bill and collect payment for charging sessions, GPS navigation can locate and reserve EVSE-equipped parking spaces, and more innovations are in development.

National Initiatives

Here are highlights of EV charging infrastructure supported at the national level. There are a myriad of EV infrastructure projects under way across the country. To read more, check out REVI’s Useful Links to EV websites or search the Internet.

Grant funding from the U. S. Department of Energy (DOE) supports The EV Project which kicked off in October 2009. According to their website, the EV Project "collects and analyzes data to characterize vehicle use in diverse topographic and climatic conditions, evaluates the effectiveness of charge infrastructure, and conducts trials of various revenue systems for commercial and public charge infrastructures.."

  • The EV Project, managed by ECOtality, has deployed electric vehicle charging infrastructure in 21 major cities and metropolitan areas in nine states and the District of Columbia.
  • The EV Project has funded the installation of Level 2 charging in homes, as well as at businesses and municipalities, and has also deployed fast charging stations, to enable the collection of data from diverse sources.
  • The ultimate goal of The EV Project is to take the lessons learned from the deployment of the first thousands of EVs, and the charging infrastructure supporting them, to enable the streamlined deployment of the next generation of EVs to come.

Source: www.theevproject.com/overview.php 

The U.S. Department of Energy's Alternative Fuels and Advanced Vehicles Data Center (AFDC) is a clearinghouse of data, publications, tools, and information related to advanced transportation technologies.

  • Sponsored by the Clean Cities initiative and technically administered by the National Renewable Energy Laboratory, the AFDC hosts thousands of documents, interactive tools that help fleets and consumers make transportation decisions, and a wealth of information to educate the public on alternative fuels and advanced vehicles.
  • The AFDC offers the most comprehensive set of data on the locations of alternative fuel, including:  

Equipment standardization is key to mass-market development of EVs and, in turn, their potential benefits as a cleaner, cost-efficient transportation alternative.

  • The SAE J1772 connector is the Society of Automotive Engineering’ industry standard for EV charging equipment. The conductive-style, 5-pin plug is used by most new EV models. More information is on SAE’s website.
  • The EPRI-General Motors Plug-In Electric Vehicle Demonstration Project is a three-year initiative (2010-12) by the Electric Power Research Institute (EPRI) and dozens of participating utilities (including REVI members). Data collected from Volt test vehicles will help develop production-capable standards for “smart charging” and other advanced interfaces with the electric grid, in anticipation of potentially a million or more cars plugging across the country.

REVI Utilities’ Early Infrastructure Projects

REVI utilities are testing EV charging equipment, analyzing market models and collaborating with state agencies, local communities, businesses and individuals interested in the potential economic and environmental benefits of electric transportation. Current REVI project highlights:

United Illuminating: EV charging stations with New Haven (Conn.) Parking Authority, residential EVSE beta testing in service territory

National Grid: Ford Escape EV demonstration project in Mass., Rhode Island, and New York; Mass. Department of Energy Resources (DOER) grant-funded municipal charging stations

NSTAR dba Eversource Energy: Mass. DOER grant-funded charging stations in Boston metro area and other municipalities

Massachusetts Municipal Wholesale Electric Company: Designated members receiving DOER grant-funded municipal charging stations

Connecticut Municipal Electric Energy Cooperative: Designated municipalities in the Connecticut Clean Cities Future Fuels Project (funded in part by the USDOE through the American Recovery and Reinvestment Act)

Eversource Energy: EV research project to test charging stations with business and municipal customers of Connecticut Light & Power and Western Massachusetts Electric company.

To supplement our base of EV experiences, REVI members also access the ongoing work of technical experts such as the Electric Power Research Institute (EPRI, the National Electric Transportation Infrastructure Working Committee (IWC), and the Electric Drive Transportation Association (EDTA).