XCELLSIS fuell cell engine
Computer rendering of XCELLSIS fuel cell engine integrated into automotive frame. Such engines can generate up to 90kW of electricity.

Get Ready For V2G - Part 2

An interview with Dr. Willett Kempton, University of Delaware

By Bill Moore

Caught between the forces of corporate greed and half-baked utility deregulation, some state regulators in California have begun to take a serious interest in the concept of using electric-drive vehicles to provide power to an energy-starved grid. If it can be demonstrated that EVs could be counted on to augment the state's energy needs, it would offer an innovative new solution to California's growing energy needs. It also would provide a powerful economic incentive for the development and deployment of battery electric, hybrid-electric and fuel cell vehicles.

So, the California Air Resources Board and the Los Angeles Department of Water and Power commissioned Kempton and his team of academicians to look at the state's power market and determine the economic potential of the vehicle-to-grid (V2G) concept.

What they found was a segment of the power market called "regulation services," which could provide owners of battery electric vehicles (BEVs) with as much as $3,000 a year in income. (See Part 1).

While V2G shows potential in California, does it make sense elsewhere?

"There's not really anything different about other parts of the country," Kempton told EV World. The exceptions are a few regions and states that currently have a surplus of electrical energy.

Beyond Theory

For the V2G concept to work, it eventually will require the active participation of carmakers, utilities and system operators, as well as state regulators. None of the current crop of either battery electric or hybrid-electric vehicles have the ability to feed power back into the grid. There are not two-chargers with V2G communications capability. And no one has yet figured out how bill for such services.

The first tentative step -- mechanically -- towards V2G is AC Propulsion's new generation two drive train, reported Kemtpon. All of the necessary two-way power electronics are built into a single power control "box." Kempton said that carmakers could integrate this into their EV drive trains, adding that the incremental cost of building V2G into an EV is comparatively small. In contrast, adding V2G to an existing EV is not practical, he said.

It might make sense, however, to convert a fleet of EVs using AC Propulsion's new power electronics, Kempton theorized, but he wouldn't speculate which vehicles offer the best conversion potential. He did state that he was aware of one "world-class" automobile manufacturer who is investigating adapting their power electronics to make V2G possible.

Kempton also reported that on the utility side, the California ISO has had discussions with AC Propulsion on the protocols for a radio-based response system for feeding electricity into the grid from an EV. "They see it as potentially higher quality of regulation than they have been able to get. They might actually use regulation in somewhat different ways, and thereby increase the reliability of the grid, increase the stability of the grid so there is less fluctuation. And that makes it better because (with) electronic commerce there is a real demand for higher reliability and stability. So this is a way the grid can do that in a cost effective way."

What Kempton and his V2G colleagues are proposing might eventually cause a shift in our current vehicle ownership paradigm. It may make good economic sense in the future for the ISO or utility or even a car share company to actually own the vehicle instead of individuals. Commuters could rent or lease the vehicle for short-term, avoiding many of the costs of vehicle ownership. When not in use, the EV would be providing regulation services.

As with many issues facing electric vehicles, the V2G proposal is confronted with the same classic "chicken or egg" connundrum. Carmakers won't want to incorporate the necessary electronics into their future electric-drive vehicles to make V2G possible until there is a supporting utility or ISO infrastructure.

But grid operators won't want to go to the expense of installing or upgrading the necessary equipment and communications systems until there are vehicles capable of being safely connected to the grid.

Then too, there is the task of developing a micro-metering system to handle billing of services between the grid and the vehicle owner. Here Kempton says the cellular telephone industry might serve as a working model since it has experience in micro-metering e-commerce.

On the regulatory front, while there are some issues to be addressed here, Kempton told EV World that they are relatively minor. "It might mean a somewhat different rate schedule that might be added to current utility rate schedules. It might mean another look at the national electrical code, which can be read as prohibiting this type of vehicle, although I think a thoughtful reading of is shows that as long as you disconnect when the power is off, it would be okay."

AC Propulsion has integrated this safety feature already into its V2G control system, Kempton stated. This means that if the grid is off, the vehicle will not supply power off the vehicle. While this means you won't be able to power your home in the event of a power outage, someday having lots of V2G EVs on the grid would mean there would be fewer outages that would necessitate powering your home with your car.

And the Winner Is...

When the California Air Resources Board recently endorsed the conductive charging standard for electric vehicles, it did so, in part, because only conductive offers V2G capabilities in the future. This pretty much spells the death knell for the inductive charging standard developed and heavily subsidized by GM. Cars like the EV1 would be excellent V2G candidates, but it can't send energy back into the grid, a concept that wasn't anticipated in the early 90's when the car was originally developed and when it was felt that inductive offered superior convenience and safety.

If V2G looks good in California, it looks even better in Japan, Kempton found when he and Toru Kubo looked the land of the rising sun. It turns out that for cultural and infrastructure reasons, V2G looks very promising there. Instead of driving their cars every day, many people in Japan use trains to get to and from work. They only drive their cars on weekends, offering an excellent opportunity to utilize their personal vehicles in a V2G model.

"In Japan there is a very serious problem with peak power," Kempton explained. "For cultural reasons you have these very big peaks in demand later afternoon as people are coming home the rice cookers are coming on prior to the working member in the family -- probably the husband -- coming in.... So there is a real need for peak power. The beautiful thing is that you've got all these cars parked at that point and if they're electric vehicles they can be plugged in..."

Achieving Critical Mass

Assuming all the various, often competing, parties can be persuaded to take V2G seriously as viable economically and achievable technologically, is there a critical mass of EVs necessary in order to make this happen?

Kempton speculated that since the typical electricity contract is usually measured in megawatt units. "We back calculated, assuming either a fuel cell vehicle. . . a full-functioned battery electric vehicle at something like a 16 kilowatt output, at sixty vehicles a fleet operator could have a megawatt contract. So, that's actually quite small."

He and his fellow researchers also looked at what impact the Zero Emission Vehicle mandate would have in California by the year 2008, some five years after the mandate took effect. They found there could be the equivalent of 2 gigawatts of electricity available or approximately the output of two nuclear power plants.

"I think one thing that would be helpful right now would be if buyers of EVs to start specifying V2G capability in their specifications for purchases."

"Again, it is so cheap to add (V2G) to battery vehicles that a little bit of that would get some attention and would give a little push to adding it just as standard feature or maybe as an extra cost opinion."

Times Article Viewed: 6153
Published: 03-Sep-2001


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