To support the Obama administration's goal of one million plug-in hybrid vehicles on the road by 2015, Congress has provided up to $7,500 in tax credits for the purchase of electric vehicles (EVs) and as much as $25 billion to develop alternative fuels. Current measures in the Senate and House of Representatives offer even more incentives and specifically address the need for EV charging infrastructure.

The Senate bill offers $2,500 more to consumers in tax credits while providing up to $250 million in grants to build EV charging infrastructure in 15 different jurisdictions. The version in the House of Representatives, the “Electric Drive Vehicle Deployment Act of 2010,” gives consumers $2,000 more in credits while allocating $800 million in grants for EV charging infrastructure to five different areas of the country.

“We think these bills do a great job of laying out what needs to be done in order to get the penetration rate of grid-connected vehicles into the U.S. market,” says Ron Minsk, senior VP for policy for Securing America's Future Energy (SAFE), the Washington, D.C.-based action-oriented, nonpartisan organization that works to reduce America's dependence on oil, educating policymakers, and advocating for comprehensive energy reform and representative of the Electrification Coalition, Washington, D.C., a group of business leaders representing the electrified transportation sector. “We'd be happy if either of them passed.”

In November 2009, the Electrification Coalition published the “Electrification Roadmap,” a public policy guide for transforming 75% of the miles traveled in the United States by the light-duty ground transportation system — comprised mainly of privately owned vehicles for personal use — into electric miles by 2040. To support this goal, the report calls for the initial establishment of “electrification ecosystems” in six to eight cities in which infrastructure supports 50,000 to 100,000 EVs on the road per city by 2013, with an increase to 400,000 to 500,000 EVs per city by 2018.

This is followed by an increase in the number of electrification ecosystems to 20 to 25 additional cities with charging infrastructure to support 75,000 to 150,000 EVs per city by 2018. “At first, these vehicles will be used in applications in and around a single city,” says Minsk. “These vehicles are more likely to be the choice of people who plan to use them primarily within the community and whose typical driving needs would allow them to do what they need to do on a full charge each day.”

Driving range

Although the ability to charge at home will eventually be important for achieving high rates of EV use, the roadmap argues that public charging is more important for the initial deployment of EVs. Accustomed to being able to refuel at ubiquitous gas stations, new EV drivers may feel “range anxiety,” which is the fear people have of driving too far and possibly getting stranded if they can't find a charging outlet. “At first, there will be a need for more public charging than is needed to operate the vehicles in order to address range anxiety,” says Minsk. “People need to see chargers around to give them the confidence that they're not going to get stuck.”

Palmer Electric Co., Winter Park, Fla., is expecting an influx of EV infrastructure projects to support its new Green Energy Services department. Orlando is among one of the nine U.S. cities on the list to receive 4,600 free chargers for public and private use, funded in part by $15 million in stimulus funds administered by the U.S. Department of Energy (DOE). It is estimated that more than 1,000 public stations will be installed nationwide by December, with the remainder in place by September 2011. “Lots of places — municipal properties, shopping centers, universities — would benefit and are interested in installing a station,” says Thomas G. Beard, president, Palmer Electric. “But there's more to it. People are going to need chargers in their homes, and they're going to need wiring for the chargers in their homes. All of this is going to require licensed electrical contractors. In our industry, there hasn't been a whole lot of opportunity for new vertical markets. This is just the beginning.”

In January, Palmer Electric completed the $170,000 electrical contract on the Smart Solar Plug-In Test Facility at the University of Central Florida (UCF), Orlando, Fla. (Test Facility below). Funded by a research grant from the Florida Energy Systems Consortium (FESC), Gainesville, Fla., the $380,000 solar charging station (Photo 1) generates 50kWh of energy daily. When no plug-in hybrid electric vehicles (PHEVs) or battery-powered EVs are being charged, the two solar arrays on the carport feed energy into the main power grid of the campus. Currently, there are four parking spots (Photo 2), each with their own charging outlet on an aluminum pedestal (Photo 3). An additional two spaces have been equipped with conduits to support EV charging stations scheduled to be installed later this year when they become available. These two new stations will come equipped with SAE International's standardized J1772 connector (Plug and Play).

However, the number of public charging stations that will be needed has not yet been determined. The roadmap recommends a combination of charger levels at various commercial locations (EVSE Ratings below). “At the outset, when people have this concern, until they have a better level of comfort with how the vehicles work and have confidence in the range, we're better off having 20% too many chargers than 20% too few,” says Minsk. “If you have too few, you increase the risk of the experiment failing.”

But according to Dan Davids, president of Plug-In America, the San Francisco-based coalition of EV drivers and advocates of clean air and energy independence, the issue of public charging infrastructure is moot. He says it and the chicken-egg conundrum symbolizing EVs and public chargers are myths created by EV skeptics and fostered by the media. “To some extent, those are fabrications,” he says. “Once we get the cars on the road, a lot of this is going to become a lot clearer to people.”

With a driving range of about 100 mi, EVs do have a limit; therefore, Davids doesn't entirely dismiss range concerns. “I don't want to say there aren't people who aren't concerned about range — and that there isn't a need for public charging infrastructure — but certainly neither of those rise to the level of something that has been keeping electric cars off the road,” he says. “Public charging stations will widen and deepen the pool of people who can get involved and buy them, but they are not necessary to the success of electric vehicles.”

Home improvement

Plug-In America estimates that 90% of charging will take place at private residences at night. “It will be done the same way most people charge their cell phone,” Davids says. “In the morning, you get up, and your car is fully charged.”

For faster charging, homes require installation of a 240V plug in their garage, carport, or driveway. “When you think about it, it's really nothing more than putting in another electric dryer circuit,” says Davids. “It's pretty simple.”

In addition to adding a charging circuit to his own house, Stefano Paris, a Southern California-based EV advocate installed circuits in the garages and carports of his friends' houses as well. “I wasn't about to spend $1,000 a month leasing an electric car and be leashed to my house with a 40-mi radius,” he explains. “Not when I can put in two 50A outlets and breakers and a 20A NEMA 520 duplex receptacle and be able to charge two electric cars and maybe a plug-in hybrid or an electric scooter. This makes every house a potential charging station.”

Obviously, installing the circuits is easiest in new residential construction projects. Retrofits in older homes may be difficult and cost prohibitive for the owners. “The issue in older houses is panel capacity,” says Davids. “But electricians can tell homeowners if they have extra service capacity well before the car arrives. Any extra upgrades should be taken care of ahead of time.”

Installing chargers in multi-family residential units could also be a problem. Some states, such as Hawaii and California, are passing legislation preventing the barring of charging stations in condo parking spaces by condo associations. In addition, in Arizona, several multi-family rental properties have received federal funding to cover the costs of charging stations.

Public charging could also allow condo and apartment dwellers the ability to own an EV. However, for a driver who relies on public stations for all the car's charging, there's a fairness issue, says Davids. “Even though electricity's cheap compared to gasoline, there's still the issue of paying for the electricity.”

A profitable business model for public charging infrastructure has not been reliably demonstrated, according to the Electrification Coalition. Before any federal tax credit, a Level II charging station with a dedicated circuit is estimated to cost an average of between $2,200 to $5,000 (not including installation costs). To recoup investment costs, some charging station owners set their own prices. The public utilities commissions for both California and Hawaii recently ruled that charging stations are not under their jurisdiction for rates and regulations, allowing station owners free to charge according to their own specifications. Some charge rates are determined by time of day and calendar date, similar to parking meters.

However, there is a limit to the price EV owners are willing to pay for the electricity, particularly when compared to the low rates of at-home charging. In addition, Plug-In America and other EV advocates are working toward guidelines that would prevent price gouging. But, according to Davids, awareness of the market should take care of an unfair pricing. “If everybody knows that there's a charging station that charges $5 every time you plug into it, it's not going to get used,” he says.

There are companies that provide free charging as a value-add to their retail business. For example, in California, many Costco locations offer free EV charging to their members. “While you're there to pick up a few things, you might put another 20 min. of charge in your tank, which gives you a little more flexibility and maybe extends your daily operating radius,” says Davids. “Costco doesn't care that they spend 10 cents in electricity during the hour you're there because the likelihood is that you're spending hundreds of dollars in the store.”

Use of the UCF solar carport is free for 10kWh of power or less. For more than that, there is a charge for the electricity from the campus' power grid. There is a plan to have a payment mechanism installed.

Grid rules

In some cases, the electricity used to power EVs is generated by coal plants. This lessens the emissions-savings impact for many EV drivers. Therefore, many EV advocates champion renewable energy sources.

Solar energy and electric cars are a natural match. By factoring in the costs of both electricity and gasoline, the return on investment for solar systems is shortened considerably. “If you look at it solely based on the cost of electricity, it might take you a decade or 15 years to pay off that solar system,” says Paris whose 4kW system powers his home and EV, currently a leased all-electric Mini Cooper, the Mini E. “But if you're also offsetting $3- to $6-a-gallon gasoline, that solar system is pretty much in the black. It's an amazing synergy.”

For the UCF solar charging station, Palmer Electric routed the wiring from the PV panels into the structure, down the columns, into underground conduits, and finally up into the cabinets. The electrical contractor also installed the solar system, which comprises 48 195W bi-facial — meaning they can collect an extra 30% more power from light reflecting from under the structure — solar panels in two arrays, each with four strings of six PV modules. Generated solar power is grid-tied using two 5,000W DC-to-AC inverters. In case of a safety issue, there are two power shutdown buttons that disconnect the solar array from the grid and shut down the solar power inverters.

Even when solar-powered, EVs are mainly tied to the grid. Recently, a group of U.S. and Canadian power grid operators who manage most of the North American bulk electric grid reported on the effect EVs would have on the electric power grid once fully rolled out.

The study, “Assessment of Plug-in Electric Vehicle Integration with ISO/RTO Systems,” by the ISO/RTO Council (IRC) revealed that EVs will likely be concentrated in metropolitan areas (the electrification ecosystems) of the West Coast and Northeast. The report concluded that potential negative effects on the electric load from EVs could be reduced through staggered charging, but that power companies will still need new tools to manage the widespread adoption of EVs. Those plugging into the grid in U.S. ISO/RTO regions could add electric load of 3,785MW if every EV charged simultaneously. In contrast, electric load would increase by only 819MW if charging were staggered over an 8-hr period and less than 546MW over a 12-hr period.

The new SAE International standard, J2836/1, “Use Cases for Communication Between Plug-In Vehicles and the Utility Grid,” establishes two-way communication between plug-in EVs and the electric power grid for energy transfer and other applications. It also provides a set of communication requirements for use with various load-management and rate programs that will be established by utility companies related to the charging of EVs.

The various utility programs will enable consumers to charge their vehicles at the lowest cost during off-peak hours and will help utilities reduce grid impacts by minimizing electric vehicle charging during peak periods. “The biggest challenge for utilities is managing the grid during peak times, a time when energy is the most expensive and demand is greatest,” says Rich Scholer, chairman of the SAE Hybrid Task Force. “As we add more plug-in electric vehicles to the grid, we're increasing our need for on-peak power and infrastructure. This standard will help enable consumers to charge their vehicles at off-peak hours and help utilities better manage the grids during peak hours, thus minimizing cost and grid impacts. Eventually, EVs will interface with a home area network, and if they need a faster charge, then maybe they won't run their air-conditioner for a few minutes. They'll let the charge go to their car and still balance the grid loading.”

This standard is the first in a series of five standards that are being developed by SAE to address utility programs for plug-in electric vehicles. For more information on the standard, visit

Sidebar: Test Facility

The School of Electrical Engineering and Computer Science at the University of Central Florida, Orlando, Fla., plans to use the Smart Solar Plug-In Test Facility as a platform to test its DC to DC-into-EV conversion technology, which could potentially reduce the 10% conversion loss as experienced in the traditional DC to AC-into-EV-battery process by half. The school will also test technology to move energy from EV batteries to the grid, or Vehicle to Grid (V2G), which would allow the owner of an EV to sell stored energy back to the electric utility.

In order to make it possible for students to measure the system's performance, reconfigure components based on test results, and install new technology, Matern Professional Engineering, Inc., Orlando, Fla., and Palmer Electric Co., Winter Park, Fla., designed and installed the project to include large equipment cabinets (Photo 1 on page 22) so that entire sub-assemblies could be installed in a dry, clean environment for easy measurement and replacement. Wiring from the solar panels enters the cabinet in smaller strings — three panels to a string — so that students have the ability to route smaller amounts of power to their devices being tested. Several disconnects and measurement points were added along the power path to allow students to take measurements, and wires were labeled so that students can identify what they are measuring. Preplanning ensured that wiring was concealed and no additional access points would need to be cut into the clear anodized aluminum structure.

“The structure had to allow future modification,” says Thomas G. Beard, president, Palmer Electric. “The design was in conjunction with the university's electrical engineering department. They had some unique requirements.”

Sidebar: EVSE Ratings

There are different ratings for electric vehicle supply equipment (EVSE) for charging, according to the National Electrical Code (NEC):

  • Level I: Weatherized 110V,15A 3-prong outlet/plug compatible with the NEMA 5-15R grounded electrical outlet.

  • Level II: Employs permanently wired EVSE that is operated at a fixed location. This equipment is used specifically for EV charging and is rated at less than or equal to 240VAC, less than or equal to 60A, and less than or equal to 14.4kW — and uses the coupler specified by SAE International's J1772 standard.

  • Level III: This equipment is used specifically for EV charging and is rated at greater than 14.4kW.

Sidebar: Plug and Play

In January, SAE International, the global association of more than 128,000 engineers and related technical experts in the aerospace, automotive, and commercial vehicle industries, updated its standard related to the design of the coupler used for charging electric vehicles (EVs). SAE J1772, “Electric Vehicle Conductive Charge Coupler,” provides a common interface between the inlet for plug-in hybrid electric vehicles (PHEVs) or battery-powered EVs and the connector on electrical charging systems. In the standard, SAE spells out the general physical, electrical, and performance requirements for the coupler. Under the standard, automakers can work off the same blueprint for the inlet, and makers of charging systems can follow the same plan for the connector.

“I'm all for having a standardized plug connector for the car,” says Stefano Paris, a Southern California-based EV advocate who used to travel in his leased EV with an estimated 60 lb of cables and adapters in the back in order to use the legacy chargers left over from California's 1990 Zero Emissions Mandate (repealed in 1996). “It's ridiculous that for 20 years every EV has had its own plug. We've ended up with all these incompatible products, so the J1772 connector is phenomenal in that respect.”

SAE J1772 was developed by the SAE Hybrid J1772 Task Force in cooperation with major automotive original equipment manufacturers (OEMs) and suppliers, charging equipment manufacturers, national labs, electric utility companies, universities, and standards organizations from North America, Europe, and Asia. In the process of development, a production tooled coupler has passed testing by Underwriters Laboratories (UL), Northbrook, Ill., for safety and durability.

EV proponents have expressed dismay that the full specification of the coupler goes up to 80A, yet manufacturers have agreed to make up to only 32A. “What I'd like to see is an 80A full J1772 spec,” says Paris, explaining that under normal conditions, the cars are charged at between 15A and 30A overnight. “It doesn't mean you're going to charge at 80A. There's no reason to suck down lots of power unless you need it, but you should have the capability of charging all the way up to 80A.”