Scottish wind farm
Scottish wind farm. V2G proponents see a surprising synergy between the erratic nature of wind energy and vehicle-to-grid hybrids, including fuel cell and battery electric vehicles. A recent study co-authored by Kempton, sees wind power’s contribution to the electric grid increasing above the present 15% limit to more than 50% when as little as 10% of the US automotive fleet is V2G-capable.

V2G Gaining Momentum

Dialogue with University of Delaware theorist, Dr. Willett Kempton on Seattle V2G Forum

By Bill Moore

Last month a forum was held in Seattle, Washington, co-sponsored by Sustainable Ballard and Seattle City Light, the local utility to discuss the status of the vehicle-to-gird or V2G concept.

Dr. Willett Kempton is one of the original developers of the idea, along with his colleague Dr. Steve Letendre from Green Mountain College. He was one of more than a dozen presenters at the V2G Forum that was held over two days in Seattle's city hall. EV World talked to Dr. Kempton after the event to find out what was discussed and where V2G goes from here.

He began by recapping briefly what V2G is, explaining that unlike plug-in hybrids, the electronics onboard the vehicle are designed to allow electrical energy to flow both into and back out of the vehicle; in effect, making a V2G hybrid a distributed energy storage and generation device. Powered by either batteries alone, an internal combustion engine or fuel cell, a V2G hybrid could deliver electric power into the local grid, as well as take power out of it.

"There are times", he told EV World, "when it would make sense to the electric grid to have that electricity provided back out from the vehicle; and it makes enough sense that we think the grid operator, the electric utility, or the distribution operator would be willing to pay for it".

The V2G concept is built on two key points: most cars are parked an average of 23 hours a day, and as they become increasingly electrified or hybridized, it makes sense, Kempton, believes to find a way to utilize that potentially huge power and energy storage system, one that might actually eliminate the need to build additional centralize power plants.

When Kempton and Letendre first proposed V2G in a 1997 paper -- and EV World was one of the first publications to discuss it -- they freely admit they didn't have a firm grasp on the technology or its implications. In the intervening years, the idea hasn't been completely dormant. He and various colleagues over the years have now developed 17 mathematical equations to help carmakers, utilities and community planners better understand the dynamics and costs of such a system. At present, only AC Propulsion in San Demas, California have engineered a true V2G electric drive system.

Kyoto Catalyst for Seattle Forum
Kempton explained that the catalyst for the two-day forum in Seattle were members of the local activist and policy community, inspired by Seattle city mayor, Greg Nickels, who has been one of the driving forces organizing 132 other U.S. mayors to agree to voluntarily abide by the Kyoto Protocols, in clear defiance of the Bush Administration's position on the treaty. The city of Seattle is looking for ways to cut its greenhouse gas emissions and since much of the Pacific Northwest's power comes from hydroelectricity, plug-in hybrids and V2G cars would help make a serious dent in the region's gasoline fuel consumption and resultant CO2 emissions.

Dr. Kempton estimated that some 200 people attended the forum including venture capitalists and utility and city officials.

In addition to the forum in Seattle, the Kempton-Letendre team recently had two papers on V2G published in The Journal of Power Sources. The first paper explains the concept and lays out the formulas for calculating the amount of energy that might potentially be available from battery electric, plug-in hybrids and fuel cell vehicles. Also included are formulas to determine the costs to the vehicle owner in terms of fuel consumed and wear ‘n tear on the engine and batteries.

He explained that the most promising, near-term market in which V2G automobiles could participate someday is "regulation services", which is a $10 billion market.

"That requires very fast response. Right now that means from generators that can respond very quickly by ramping up or down in power. The best type of vehicle to provide this sort of power is the battery electric vehicle," he stated.

Other potential markets and ones better suited to plug-in hybrids and fuel cells are "spinning reserve" and back-up power for renewable energy sources like wind and solar.

The second paper deals with questions of implementation and here he noted that if just one quarter of the U.S. automotive fleet were V2G-capable today (meaning each had an average of just 15kW of onboard generation capacity), they could generate all of the electric power currently being consumed in America.

"The lights wouldn't even dim," he remarked.

The paper also examines how to balance the needs of the vehicle owner who has to have sufficient energy to still get around and the needs of the utility that wants to make use of all that energy sitting out there in the garages and parking lots of America and the world.

It also looks at various business models that could help stimulate development of these vehicles. Both papers are available in PDF format as pre-publication proofs at the University of Delaware V2G web site.

Taming Those Wild Wind Farms
One very interesting outcome of their research was an analysis of what would be the impact of a V2G fleet on renewable energy sources like wind and solar. Kempton calculates that if the US automobile fleet were made up of as few as 10 percent and up to 38% V2G hybrids, it would be possible to have wind power provide over 50 percent of the nation's energy needs despite its erratic nature; the fleet would balance out the peaks and valleys of energy production.

"That's a synergy that we really didn't expect, that you‘d get such large amounts of fluctuating wind power and solar power by just changing the ways the vehicles work".

One of the keys to successful V2G power sales back to the utility, Kempton pointed out, is buying your initial energy for a low price and selling it back to the grid at a higher price. Also, the generating vehicle doesn't have to be near the power plant, it can be anywhere within what is called the "control area", essentially the area serviced by the dominate utility in the region. Power that gets put into the grid from a V2G automobile eventually "ripples" its way back to the power plant, reducing the amount of coal or natural gas or nuclear power that needs to consumed.

As for potential safety issues, such as "islanding", which isolates a generator from the grid in order to insure that utility linemen are not electrocuted while repairing downed power lines, etc., Kempton said that V2G automobiles would have to comply with all the relevant safety standards. If they sensed there was no power coming in from the grid -- due to a power outage of some type -- they would not send power into the grid.

"This is the way the AC Propulsion system works. They've already got that wired in". Besides ACP, he estimated that there are about a half-dozen companies involved in some aspect of V2G technology development. He also believes that until large numbers of V2G vehicles take to the streets there will be little need to upgrade the local grid. It is only when significant numbers of rechargeable hybrids become reality that utilities will need to consider upgrading their infrastructure.

He said that his research suggests that having 15-20kW of generating capacity on each vehicle is sufficient, but this will require more battery capacity than is currently available in cars like the Prius, which does not presently offer V2G capability and has only about 2kWhr of battery storage.

"It's something that you could work with and generate a little bit of revenue," he added.

By contrast, a highway-capable, battery electric vehicle like the former Honda EV+ or Toyota RAV4 EV offers 80-100kW of potential V2G energy.

"There is a lot of power on board, but to get that off the car and into the grid is more challenging. We've looked at a lot of constraints: the cost of the power electronics to get that higher power out, the cost of plugs, how much is available in a house, for example… We think maybe 15, 20 kilowatts makes sense. It's a small enough amount. It's easy to wire. It looks like a very large appliance. It's not something you need to design from scratch. It's a small enough amount that the vehicle could run for sometime, maybe a couple of hours producing power without depleting its store. So, we think a practical amount is about 15 kilowatts".

The Future May Not Be In Detroit
He sees fleet conversions being the most logical next step to creating market pull for the technology, an approach currently being pursued by EnergyCS and the CalCar's Intitivate.

He also thinks that non-automotive entities from local governments like Seattle to large wind farm operators could decide to take the initiative in order to gain that storage capacity, enabling them to bring more wind turbines online.

"The political impetus may come from another country or organization that is primarily concerned with electricity, renewable energy, CO2 reduction, or just from producing wind machines. That may be where it comes from.

"I don't see the automobile companies seeing this as a big business opportunity. It really is kind of a different business for them. They are not in the business of figuring out how to make the electric grids work efficiently".

He thinks that in the beginning, V2G conversions will be done by local shops similar to the way stretch limos are built. For an investment of under $10 million dollars and a handful of employees, these businesses could turn out a V2G car a day. "You're producing 200, 250 vehicles a year, which feeds a specialty market that is willing to pay a premium for cars like that, that have that capability".

Kempton came away from the Seattle V2G Forum with the surprising conclusion that many different types of enterprises and entities -- beyond traditional car companies -- could end up playing a roll in the introduction of the V2G concept.

Remember, Henry Ford once worked for Thomas Edison!

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Times Article Viewed: 13442
Published: 07-Jul-2005


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