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Electric Vehicle Chargers: Grid Devils or Energy Angels?

By 3p Contributor

By Jennifer Tuohy

President Barack Obama’s dream of 1 million electric vehicles on the road by 2015 did come true, albeit globally. And while America still lags behind by about half a million, more than 100,000 plug-in EVs were sold in the U.S. last year. That’s a 30 percent increase over 2013. The rate of adoption may not be as fast as predicted by analysts or as hoped for by the president, but it is happening. EVs are becoming a part of the American consumer landscape.

There are many groups who should be happy about this, chief among them the utility companies. EVs have the potential to be a market-changing force for the electricity industry. A report by the National Rural Electric Cooperative Association (NRECA) claims that if 100 percent of vehicles in the U.S. were fueled by electricity, consumer energy spending would shift half a billion dollars daily from the petroleum industry to the electricity industry.

That is an exciting number for utilities dealing with stagnant growth and decreasing revenues as consumers and governments adopt more energy-efficient lifestyles and policies. To some in the electricity industry, EVs are a very bright, socially and environmentally acceptable light at the end of the tunnel. Purchasing an EV will see the average American household increase its electricity use by 13 to 40 percent, translating into $340 to $515 per household, per year, according to the NRECA report.

However, the question of whether the grid can cope with EVs is an important one. As EV adoption grows, more and more consumers will charge their vehicles at home, increasing the “cluster” effect for local grids. According to EnergyBiz.com, just one or two active Level 2 Electric Vehicle Supply Equipment (EVSE) units in a neighborhood could overload a transformer. Does this mean the electricity industry will have to invest in costly infrastructure upgrades to distribution and capacity to support EVs? No — not if they can regulate how and when EVs charge.

Off-peak charging is critical

If utility companies can push EVs toward off-peak charging, then the consumer will save money and the grid can remain not only stable, but also more efficient. By charging off-peak, generally at night when less electricity is used, EVs would fill in the traditional “valleys” in system demand, helping to distribute overall energy use.

For example, a report for the Vermont Agency of Transportation, where EVs have seen a quarterly growth rate of nearly 40 percent since July 2012, found that if charging occurs off-peak, the Vermont grid is capable of supporting more than 100,000 EVs without needing to expand capacity. Similar studies across the country came to the same conclusions. This study found that, if charged overnight, 73 percent of the current number of cars in the U.S. could be EVs without the need for a single additional power plant.

However, as EV adoption grows and the proliferation of public charging stations, workplace stations and DC fast-charge stations follow suit, more and more EVs will be charging at peak times, such as during the middle of the day at work or on long road trips. When that stage is reached, the ability to control the release of power on the grid will be crucially important. To do this necessitates a smart grid.

EVs and the smart grid

A smart grid is comprised of sensors and two-way communication abilities built into the grid, the EV and the EVSE. In theory, the smart grid will be able to use the data it receives from the sensors to balance the power supply and EV demand responsively, and avoid overloading the grid. This is called demand response, and many believe it will be crucial to the long-term success of EV adoption.

In the short-term, however, EVs are not putting a strain on the grid.

“Right now, EVs are less than 1 percent of the new-car market in the U.S., and they'll have to get to a very high percentage to really need much flexibility around them on the grid,” says Zachary Shahan, director and chief editor of CleanTechnica.com, the top clean technology-focused news and analysis website in the world, and founder of electric vehicle media site EVObsession.com.

“For example, EVs have been accounting for less than 25 percent of the Norwegian new-car market, and I haven't heard of the electric grid facing any issues from that,” he adds. “By the time EVs pose a significant challenge for utilities, I think this sort of smart grid technology will be the norm. Naturally, though, its development is being hastened by forward-thinking entrepreneurs, large corporations and utilities.”

Are EVs a power storage solution for the future?

The development of the smart grid opens a huge range of possibilities beyond load control. Most intriguing is the ability for EVs to partner with the grid to store energy and discharge it when needed, making the EV an asset to the grid rather than a strain. In 2013, PG&E began a demand response pilot program to explore using EV batteries for grid stabilization.

Current grid technology leaves little room for energy storage, meaning energy has to be used as soon as it’s produced. But storage could be essential to meeting increased demand during peak periods, like when temperatures reach 90 degrees in the summer and everyone has their air conditioner running. Additionally, the current lack of grid storage renders many alternative energy sources unviable on a large scale, because there’s nowhere to put all that extra energy generated on a super-windy or super-sunny day.

Enter the EV, a potential portable mini-storage facility that sits unused for a majority of the day. Equipped with the right connections, EVs can absorb excess energy from the grid and send it back when needed. This is called Vehicle to Grid (V2G) power.

In December 2015, Nissan announced the launch of a V2G pilot project in Europe for its popular EV, the Leaf. The project allows Nissan Leaf owners and businesses with large EV fleets to create mobile energy hubs. “Electric vehicles can now become a fully integrated part of our national electricity systems right across Europe,” Paul Willcox, Nissan Europe chairman, said in a press release.

Here in the U.S., the University of Delaware has been working on V2G tech, partnering with both Honda and Nissan. However, for V2G to become a reality, an extensive (and expensive) infrastructure would need to be put in place that allows the vehicle, the grid and the end points, like homes and businesses, to communicate with each other.

Shahan notes that many are excited about this technology. But there is also some skepticism, he says, because batteries slowly lose capacity as they are discharged and charged again, meaning many owners may not want to risk decreasing the life of their battery for the benefit of the grid.

“[However], I think enough people are into the idea, and it provides enough benefit at very little cost that it will move forward,” he adds. “We've already seen and written about a number of pilot programs and initiatives where EV owners allow the local utility (or a third party) access to the car's battery in specific times or scenarios to provide brief backup, and EV owners get paid for participating.

"I think the technology is already there, and it's a matter of testing, testing, testing in order to determine what the right price is for a large enough number of EV owners to make it a useful demand-response mechanism for utilities.”

Yes, your car could power your home

In the interim, technology that lets consumers use their EVs to provide power to their homes, known as V2H, is quickly progressing.

An EV can act as an energy backup for a house by charging during off-peak times or absorbing excess energy from renewable sources, such as a home solar system. It can then supply that energy back to the house during high-demand times. EVs can also be used to power a home during an emergency, like a gas-powered generator. All that’s required is a device to hold the charge from the car that can be connected to the home’s distribution board.

The recently announced Honda Power Exporter 9000, a new product available later this year, could do this. According to Honda, it’s “an external power feeding device that enables AC power output from a fuel-cell vehicle with maximum output of 9 kilowatts.” This technology is already available in Japan, where Nissan sells a Leaf-to-Home System that resembles a giant battery and plugs into the Nissan Leaf to take on excess power. It then connects to the home’s distribution board to distribute that power when needed.

Shahan sees using an EV to power a home as a temporary solution that’s best for emergencies rather than long-term use, again because of battery capacity concerns. “I don't think a large percentage of customers would be eager to use their EV like a stationary energy storage system — they'd be better off choosing a storage system optimized for such use, like the Tesla Powerwall. For very occasional use as backup during a blackout, I think it makes sense, and it's already been done by some clever individuals in the U.S.”

The real potential for this technology lies not with the individual consumer’s EV, but in the fleets of large corporations that sit idle for predictable periods of time.


Electric vehicles are at a tipping point, poised to transform America’s energy consumption. Coupled with a shift away from generating electricity via fossil fuels and toward the use of renewable resources, the large-scale adoption of EVs and use of their storage capabilities is a vital step in the quest to end dependence on dirty power and push us toward a cleaner, greener planet. All this makes the EV an angel of the sustainability movement.

Image credits: 1) & 2) Shutterstock (purchased by the author for use in this article); 3) Courtesy of Nissan

Jennifer Tuohy is a tech enthusiast who has always been intrigued by electric vehicles and their impact on the environment. Jennifer provides insight on the best times to charge your car and the type of EV charger that’s best for you.  Click here to see Home Depot's selection of EV Chargers.

3p Contributor

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