Public Power Magazine

Charge It: Smoothing the Road for Electric Vehicles

From the March-April 2012 issue (Vol. 70, No. 2) of Public Power

Originally published March-April 2012

By Alice Clamp
March-April 2012
Orlando Utilities Commission is facilitating the installation of approximately 100 ChargePoint public charging stations in its service territory. Photo courtesy of Orlando Utilities Commission.

There's a term that pops up frequently when people talk about electric vehicles. It's "range anxiety."

Karl Rábago, Austin Energy's vice president of distributed energy services, puts it this way: "If you buy an electric vehicle, will you always be able to charge it?"

The fear of being stranded far from home can be a barrier to the expanded use of electric vehicles. That's where public charging stations come in, said Rábago. "We think the most important function of a public charging network is to make our customers feel comfortable enough to take a step into electric transportation."

EV Project. And that's a key goal of the Electric Vehicle (EV) Project, a major public-private undertaking by ECOtality, an electric transportation and storage technology company. The project seeks to deploy 8,300 Nissan Leaf and Chevrolet Volt vehicles and more than 14,000 charging stations in 18 major cities and metropolitan areas in Arizona, California, Tennessee, Oregon, Washington, Texas and the District of Columbia.

Launched in 2009 with nearly $100 million in American Recovery and Reinvestment Act (ARRA) funding from the U.S. Department of Energy (DOE), the project has since received an additional $15 million. Support from project partners has raised the total to $230 million.

Among the project's partners are several public power utilities, including Nashville Electric Service, Salt River Project and Seattle City Light.

Nashville Electric Service is a key partner in the EV Project, which has already deployed 450 public charging stations in Tennessee and plans to install another 300 to 550. Eleven stations are earmarked for Nashville, and some are already operational.

"Tennessee was one of the original launch states for the project," said Carla Nelson, NES's senior engineer. "And Nashville was one of the original launch cities in the state." The Nissan Leaf, the initial project vehicle, has now been joined by the Chevrolet Volt.

NES has worked with ECOtality to identify the best locations for public charging stations. Some are Level 1 chargers, which operate on 120 volts, and some are Level 2 chargers, which use 240-volt power. In addition, there are plans for a few DC fast chargers, which can charge a vehicle in minutes rather than hours and are intended for high-density areas.

Leaf owners will be able to locate the nearest charging station using the car's GPS system, which will check the battery's state of charge and indicate all stations within a 50-mile radius.

According to an article in The Tennessean, Nashville's main daily newspaper, most of the charging stations now open in the state go unused for hours or days at a time. But the paper quoted a Vanderbilt University lawyer who owns a Leaf as saying: "Knowing the chargers are being installed makes me feel better about the car."

Seattle City Light's first public charging station was installed in mid-2011. It's one of roughly 150 planned for the city, said Dan Langdon, Seattle City Light's electric transportation program manager. "Approximately two-thirds are EV Project units," he noted. More than 1,000 publicly available stations will be installed in Washington state.

Locations for the public charging stations were selected by ECOtality—with input from regional partners, including Seattle City Light—based on factors like traffic patterns, the locations of employment centers, regional attractions and retail hubs.
Seattle electric vehicle owners can use a smart phone app to find and reserve charging stations.

Salt River Project has between 30 and 40 public charging stations in its service territory, according to Karen Smith, SRP's manager of measurement, verification and evaluation. Approximately 65 are operating in the state, with one fast charger at ECOtality headquarters.

The EV Project is one of the largest electric vehicle initiatives, but it's not the only one. Several public power utilities are participating in another program—ChargePoint America.

ChargePoint America is sponsored by Coulomb Technologies, which makes electric vehicle charging equipment. The program consists of a network of charging stations in nine regions of the country. It is funded by ARRA money through DOE's Transportation Electrification Initiative.

Among the public power utilities that have installed Coulomb's stations are Austin Energy in Texas, Rochester Public Utilities in Minnesota and Orlando Utilities Commission in Florida. The city of Kissimmee in Florida also has installed stations.
Austin Energy has installed more than 100 ChargePoint charging stations in its service territory. "We wanted a charging structure built on a five-mile grid, so customers never find themselves more than five miles from a public station," said Rábago.

These stations are part of the utility's Plug-in EVerywhere Network. But here's what is unique about the network: All the charging stations are powered by renewable energy. "It's the first charging network of its kind in the country," said Rábago.
Electric vehicle owners can participate in the Plug-In EVerywhere Network pilot by purchasing a $25 six-month swipe card for unlimited charging at any Plug-In EVerywhere station. Drivers also have the option of paying $2 an hour with a credit card.
Austin Energy also has formed a Plug-in Electric Vehicle (PEV) Readiness Initiative, to "put the pieces of the puzzle together," as Rábago puts it. Over the course of three years, the utility will work with the community to help prepare homes, roads and the electric system for PEVs.

Rábago compares this effort to a business start-up, and it has far-reaching ramifications. "This infrastructure will enable us to harness the power of mobile storage, deploy a smart grid hub in homes and businesses and establish a business model for distributed storage. This is a pretty elegant solution."

Rochester Public Utilities has installed three ChargePoint public charging stations, said Patty Hanson, manager of marketing and external affairs. "We're the first utility in the state to install chargers." She admits they have seen little use to date. "We're waiting to see where the market goes before planning any more stations." Hanson noted that an RPU commercial customer plans to install a station in 2012.

Rochester Public Utilities in Minnesota located one of its three ChargePoint stations in the utility parking lot. RPU may expand to more stations if demand picks up. Photo courtesy of Rochester Public Utilities.

Because Minnesota is not in a ChargePoint America participating region, the utility paid for the stations, which cost between $5,000 and $6,000. "The installation costs depend on the location and availability of power to serve the station," said Hanson.

One of the three stations is located in RPU's parking lot, and drivers can use it free of charge. At the other two stations, drivers can wave a credit card with a radio frequency chip in front of a reader at the station, and be billed by their credit card company at $1.50 an hour, said Hanson.

Orlando Utilities Commission is facilitating the installation of approximately 100 ChargePoint public charging stations in its service territory, said Jennifer Szaro, the utility's manager of renewable energy. "OUC will own and operate some of these stations, and the remainder will be owned and operated by our commercial customers," she said. The utility has four stations in its parking area, two of them solar-powered.

The Level 2 chargers, which are provided free to OUC, cost the utility up to $2,500 to install and maintain, said Szaro. OUC worked with the local government in determining where to site the charging stations.

In addition, through its membership in Get Ready Central Florida, OUC has actively engaged with electric vehicle stakeholders and customers throughout its service territory. "We want to ensure that infrastructure needs are being met and to better understand the needs of the electric vehicle industry," said Szaro. So far, she noted, usage has been a little slow.

Kissimmee, Fla., has installed three ChargePoint charging stations, said City Manager Mike Steigerwald. The city worked with Kissimmee Utility Authority on the stations' electrical connection. "Thanks to this project, we know what we'll need to do to facilitate the installation of residential stations," he said.

The Sacramento Municipal Utility District installed 140 public charging stations at over 40 locations in the city more than a decade ago, said Bill Boyce, supervisor of the utility's electric transportation group. Many of those stations are now being upgraded by Clipper Creek, a charging station manufacturing company that got California Energy Commission funding. In addition, the city of Sacramento and many of the local governments are installing ChargePoint charging stations as part of Coulomb Technologies grant efforts.

SMUD also is working with General Motors and Chrysler to test electric fleet vehicles. "We agreed to install a charging infrastructure, drive the vehicles and collect data—all in cooperation with the municipal government," said Boyce.

Santee Cooper is one of several utilities that are sponsoring the work of Plug-In Carolina, an independent advocacy organization that promotes electric vehicles. Santee Cooper's interest is in helping consumers adapt to electric vehicles and charge them without increasing peak demand loads, according to Mollie Gore, the utility's public relations director.

Plug-In Carolina secured a federal grant to install more than 80 charging stations across South Carolina, including nine along the Grand Strand, served by Santee Cooper. Drivers can charge their vehicles for free in those Grand Strand stations for the first three years, said Gore. "We're donating the electricity for those stations."

Public vs. residential charging. The emphasis at present is on public charging, but that trend is not likely to continue, said SMUD's Boyce. "We think roughly 80 percent of charging will be done at home. Approximately 15 percent will occur at the workplace, and about 5 percent at publicly available stations."

Public charging. One issue associated with public charging is how to pay for it. At present, most public charging—especially through the EV Project—is free. "The EV Project uses the Blink Charging system and plans to introduce a fee in 2012, but we don't know what the pricing structure will be," said SRP's Smith. "It will likely be a fee per hook-up. Because electricity sales are regulated in Arizona according to the state constitution, the fee won't be on a kilowatt-hour basis."

It's a challenge, said SMUD's Boyce. "We have yet to see anyone come up with a business model that is sustainable. No one has yet turned a profit." While the charging hardware will get cheaper, he noted, drivers will have to pay for public charging. "If a station is only used a few times a day, it will cost more to operate than the price of electricity."

The business model needs to be based on something other than energy sales, said Boyce.

Nashville Electric Service's Nelson noted that EV Project participants must provide feedback to DOE on business cases, such as pay at the pump' versus a subscription. "We'll pilot these cases with various commercial partners," she said. Like SMUD, NES is looking for a business plan that is sustainable and doesn't need a government partner.

Monitoring of public charging stations to date indicates relatively low use. That's probably a reflection of the limited number of electric vehicles on the road. But in some cases, it could be the location of a given station. "The vast majority of a public charging station's asset value is portable," said Austin Energy's Rábago. "If a station isn't getting high use here, it can be unplugged and installed someplace else."

Fast charging. With a DC fast charger, it is possible to charge a Nissan Leaf in 30 minutes, said Boyce. "Fast charging gets a lot of buzz in the press. But it still needs more work." That's because the United States has yet to develop a standard for fast chargers, he said. The fast charging stations in use today are based on a Japanese standard. "But when the U.S. standard is issued, fast charging could support different market segments such as high density housing where only street parking is available," he said.

Workplace charging. Some of the most active charging in Sacramento occurs at a downtown parking garage, said Boyce. "It's used primarily by people who work in the area. They're supporting workplace behavior."

Tomorrow's EV drivers will need access to workplace chargers, said Kissimmee's Steigerwald. "It's relatively easy for consumers to install a charging station at home, but they still need a recharge to get back from work."

Austin Energy's Rábago said drivers would probably be more amenable to a charge control signal or TOU rate if they knew they had enough power to get home. "With workplace charging, you can double the radius within which the car can travel."
Workplace charging could be a boon for people who live in apartment buildings, where residential charging may be constrained.

Residential charging. Residential customers of those utilities participating in the EV Project can opt to have a charging station supplied free of charge. In Seattle, more than 250 residential chargers have been installed, said the utility's Langdon. At least 131 Salt River Project customers have done so, according to the utility's Smith. So, too, have a number of Nashville Electric Service customers who purchased a Nissan Leaf. These customers are eligible for a $2,500 payment—through the project—to help cover the cost of installing the charger.

Elsewhere, there is less data on residential chargers. OUC, which is not an EV Project participant, has identified 11 residential customers who have installed chargers, said the utility's Szaro. "Customers are not required to inform us," she added.
Most residential customers pay for charging as part of their regular utility bill, with no sub-metering. Given the small number of customers who currently charge their electric vehicles at home, it's not an issue.

But down the road it could be.

Grid impact of residential charging. Austin Energy has already taken steps to address the growth of residential charging. It's created the Plug-in Partners Pilot Program. The aim is to help customers charge their electric vehicles at times when demand—and prices—are low, said the utility's Rábago.

"We can't tolerate dumb charging," he said. "It could pose reliability and safety challenges for the utility."

Austin Energy is using a carrot to encourage customers to participate—a 50 percent rebate on the cost of buying and installing a level 2 charging station, up to $1,500. In exchange for the rebate, customers agree to share their charging data with the utility. "We'll use that information to develop long-term revenue and demand estimates," said Rábago. The information also will help the utility to develop smart charging based on such factors as electricity prices.

SMUD customers can apply for a special time-of-use charging rate, said the utility's Boyce. That rate—2.2 cents off the normal rate after 8 p.m.—encourages customers to charge during that period. "It promotes charging at times that are beneficial to the utility." Of the roughly 125 electric vehicles in SMUD's service territory, 35 residential customers are on that rate, all of them with Level 2 chargers.

"Our grid impact analysis actually shows that the best time to charge is after 2 a.m. That's because the transformers need time to cool down from summer peaks," said Boyce. Based on the analysis, SMUD came up with a projected cost for distribution impacts. "The charging level has more impact than the time of use," he said. "A Level 1 charger pulls 1.5 kilowatts, while a Level 2 charger pulls 3.3 kilowatts now and 6.6 kilowatts for most other Level 2 charging."

SRP, too, has conducted a grid impact study. "We found we can take a residential charging penetration of 20 percent on our circuits with no harm," said the utility's Smith. "We don't expect to see that level until 2030 or beyond, so we have a long time to watch this issue."

In the meantime, SRP already offers its customers "robust" time-of-use rates. "We intend to market TOU pricing to our electric vehicle customers to ensure they charge in a way that is beneficial to the grid."

A number of utilities are examining the impact of electric vehicle charging. "We're forecasting where EV owners will live and work," said NES's Nelson. "We want to make sure there's no risk of overloading on distribution transformers and that our infrastructure will support charging."

So far, she said, the utility has seen no problems. But NES is on the lookout for any red flags, such as service drops, she added. "Our distribution transformers are sized to serve a certain number of customers, based on home loading. Electric vehicle charging is the equivalent of a half to a whole house."

Eventually, said Nelson, the utility will begin seeing impacts on its distribution lines. "We're looking at time-of-use rates as an incentive to get people to modify their behavior."

OUC is mapping residential charging stations as it learns of them, said the utility's Szaro. "We're installing monitors on some residential transformers to track their performance."

The utility doesn't anticipate any transformer issues with the addition of a few charging stations. "But multiple stations on a transformer are likely to trigger the need for an upgrade," said Szaro. OUC also may consider time-of-use pricing or incentives to help it gain information on charging patterns and provide opportunities for demand-side management, she said.

Looking ahead. It's early days for electric vehicles. And that makes it difficult to predict how the market will evolve.

Some trends, however, are already apparent.

In the near term, plug-in hybrids will lead the market, said Seattle City Light's Langdon. "There's still a lot of range anxiety out there." But as people become more comfortable with total electric vehicles, he said, "we'll see a great deal of adoption in our service territory."

SRP's Smith, too, thinks that hybrids will dominate for the next several years. "People think of the full electric vehicle as a commuter, an urban car. In Arizona, we don't see it as a vehicle of choice."

What will it take to grow the market? In a chicken/egg analogy, Santee Cooper's Gore isn't sure which comes first: the electric vehicle or the charging infrastructure. First adopters are an important market indicator, she said. "Their experience will determine how quickly electric vehicles catch on."

For OUC's Szaro, an appropriate charging infrastructure is a key factor in consumer acceptance of electric vehicles, and Kissimmee's Steigerwald agreed. "The single biggest impediment to consumer willingness to buy a total electric vehicle is the lack of a public charging infrastructure," he said.

Ten or 20 years from now, there could be tens of thousands of electric vehicles in use, all drawing electricity from the grid.

"Our challenge is how do we stimulate or modify that demand, and shape that market," said Austin Energy's Rábago. "We can't just assume demand for electricity and only plan for supply."

One option, which takes advantage of the smart grid, is called vehicle-to-grid or V2G. Here's how it could work. Electric vehicles would communicate with the power grid over a two-way system, and either deliver electricity or turn off their charger in response to grid requirements.

Austin Energy is testing this concept with several electric trucks. The aim is to determine whether fleet vehicles could be aggregated, becoming part of the statewide energy market.

The project also will explore ‘smart charging'—whether electric vehicles being charged at customers' homes could be synchronized so the chargers switch off and on to meet the needs of the grid. For example, an electric vehicle could be charged when the home's air-conditioning system cycles off, with charging halted when the air conditioner cycles back on. "We could get 90 percent of the energy benefit associated with smart charging," said Rábago.

Some day, the electric vehicle may be more than a means of transportation. It could be a dispatchable resource that helps to prevent a grid emergency.

The bigger picture: state, regional and national partnerships

A number of public power utilities are working with state organizations on electric vehicle charging projects. The Sacramento Municipal Utility District, for instance, is a member of the California Plug-In Electric Vehicle Collaborative, a public-private partnership working to ensure the viable transition to electric vehicles.

"We've made a lot of information from groups such as the collaborative available to smaller munis through the California Municipal Utility Association," said Bill Boyce, SMUD's supervisor of the electric vehicle transportation group.

Salt River Project is involved in Electric Vehicles Arizona (EVAZ), said Karen Smith, SRP's manager of measurement, verification and evaluation. The aim is to facilitate the introduction of electric vehicles in the state. SRP also is a member of the Western Electricity Industry Leaders' plug-in vehicle readiness subcommittee.

Austin Energy is working on the state level, too. It was awarded $100,000 from DOE to develop an EV infrastructure planning project called the Texas River Cities Initiative. The aim is to create a template for the efficient deployment of a cost-effective EV infrastructure in the region stretching from San Antonio to Georgetown.

Many public power utilities are participating in one or more national programs or organizations. Among them:

  • The Electric Vehicle (EV) Project
  • ChargePoint America
  • Plug In America
  • Project Get Ready
  • National Plug-in Vehicle Initiative
  • Electric Drive Transportation Association


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March-April 2012
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