V2G is particularly nice when you can run SOFCs on renewable fuels like SNG, methanol or ethanol. They can run continuously at lower output levels and supply the grid when not supplying energy for transportation.

At current battery prices, this will never work. Suppose the price of a LiIon battery is $500/kWh. Suppose that the battery has a lifespan of 1000 cycles. Then each kWh will cost the car owner 50 cents in battery write-off.

The economics however differ for short-term and long-term regulations as shallow discharges do not affect battery life as much as deep discharges.

Ok, let's think about this in practical terms. Fast forward a few years and pretend that you own a PHEV or BEV featuring fancy new battery technology. It takes 8 hours for it to fully charge off a standard but dedicated 110V 15A household circuit. Your an operating range - assuming a light touch on the gas pedal - of 50 miles. On weekdays, your commute to and from work plus various errands average 25 miles. Ergo, you normally only need to charge the vehicle for about four hours each night, though it is actually connected for about eight hours. In principle, that means your battery pack could support grid load leveling tasks for at least four hours each night. There is just one snag: there is not much call for peak shaving at night.

Moreover, your vehicle would need to be part of a (wireless) data network used to manage when and where V2G transactions are required. This would involve non-repudiable electronic authentication and authorization in both directions plus the inevitable client-side software upgrades and patches, all of which is a can of worms in its own right (though feasible).

Ok, so what if you could connect the vehicle to the grid while it is parked at your place of work during the day? This assumes the facility features the neccessary all-weather grid connection ports in the parking lot plus the trunk lines into the grid. The utility would need to pay your employer for the availability and actual use of this rather expensive infrastructure. Inevitably, that reduces the cut available to the vehicle owners.

The business end of such a grid connection port would consist of several feet of cabling on a self-winding drum and, a suitable plug. You don't want to lug that around in the vehicle. The port could support higher power levels than an ordinary household circuit. However, the 20kW number mentioned in the article implies a whopping 50 amps at 400 volts effective, far greater than anything Joe Schmoe is used to dealing with today. Short circuits and arcing due to moisture and/or soiled contacts are very real dangers that could lead to serious damage, even an electrical fire.

For safety, such an outlet would need to feature low-power handshaking circuitry plus connectivity to bespoke data network to control the port's main circuit breaker. The outlet must not be live until and unless a qualified vehicle has been hooked up correctly.

You would need to set a minimum battery charge level (expressed as remaining operating range) below which your vehicle automatically opts out of the V2G arrangement, even though it remains connected. This safeguard ensures you will be able to get home (in a PHEV, the on-board computer could set the threshold based on how full your fuel tank is).

Last not least, your battery pack would have to support far more frequent and possibly deep charge/discharge cycles while connected to the grid. Even with adequate cooling, this tends to shorten the life expectancy of your battery pack. Since the utility could not afford to pay you enough to cover a replacement pack during the vehicle's lifetime, this is a critical issue. Along with vehicle cost, weight and packaging issues, battery pack life expectancy is a major reason why no carmaker is yet offering PHEVs or BEVs.

Rafael,

That pretty much sums it up before this can be a reality. Add to that the fact that people don't like to think ahead. Having to think about how full you want the battery to be when you get back to your car, and at what time you will get back to your car will prove too much of a fuss for most people. I suspect that many people will not even bother to hook up their car at all.

However I do not agree with the data communication problems you envision. Networking over power lines is already available for some time. See: http://www.homeplug.org/en/index.asp

First, Rafael, the communications and data requirements you set out are trivial. Power exchange can also be handled inductively in the case of non-covered parking areas eliminating weather concerns and this also facilitates NFC (near field communications) which is quite reliable at 200kbits/sec comm speeds which easily handles highly encrypted data for a vehicle sitting all day with relatively limited bandwidth requirements. In fact a GSM transceiver's cost is so low that most vending machines now incorporate them for low bandwidth basic data transfer (they don't require EDGE, or CDMA-1/CDMA-2000 as all the data required could be done over CDPD and even the more mundane and earlier forms of comms which cost the cellular companies almost nothing). BTW- "quickpay" "smartpay", etc cards use NFC and there are no worries of RF since NFC uses magnetic fields at extremely low power (-110dBm would be at the high end).

Also what makes you think that everyone would be *forced* to buy into V2G just because they own an applicable vehicle?

Do you think twice before you process a credit card transaction? (other than identity theft) Those happen just fine unless there is a power outage or someone takes out the NOC and/or T-1 lines for the company. Same thing with authentication & hand shaking in this case. A simple HMAC protocol instituted into firmware ensures security in who can update your software as SHA-1 has only been cracked in theory on a piece of paper and will never happen over wireless unless you have the resources of a very large company at your disposal (we are talking about over the air interception here as the actual source connection is more vulnerable...if you have a super computer at your disposal).

Anne, Broadband over powerlines is a TERRIBLE idea that threatens our home security & public safety (plus Amateur radio operators) and the NTIA (govt version of FCC) and several non government organizations are moving to block this immediately. Broadband over powerlines (BPL) was put in place without meeting standard FCC requirements and the FCC turned a blind eye towards that but now HF radio communications are being destroyed by BPL since they don't mitigate their emissions properly(for example, the ONLY communications you had in New Orleans for long distance as all land lines were taken down (NOC, PSTNs were down), the TDMA & CDMA systems were down (cell phone companies), and VHF/UHF have limited range (repeater sites down and backbone/interconnects useless). BPL's data rates cause interference on their primary frequency (data rate), harmonics of that frequency (square waves have nasty near infinite bandwidth regardless of encoding schemes such as biphase manchester, et al), and the intermodulation products. Especially when you consider the amount of power they put behind this data transfer and how the unshielded (RF shielding not electrical) wiring acts as gigantic full wave antennas.

I think that the use of a network to even out recharge times of BEVs and PHEVs is a great idea. There is no reason why all of them need to be recharged right at 7 when people get home and plug them in. Just program in a timer that says when you'll next need a full charge. But there's no way I want my expensive Li-ion batteries life used up to power sombody elses air-conditioning.

I also think that the fluctuations of wind power have been overblown (pardon). With enough wind generation in enough diverse locations I think you will find that your production will average out quite nicely; especially if you fly your wind generators at high enough altitudes.

This is a very interesting idea. It appears that the necessary engineering is in place to provide:

1) Plug-in safety connections direct and inductive
2) Comms links and encryption via EVDO/EDGE cellular, etc.
3) Programmed levelling fetch/requests from grid source

The first application should be with fleets. Both the NYC and Sacramento fleets seem reasonable test beds. Sacramento might want to build out a PV bank that would utilize the cumulative BEV/PHEV storage as simply another storage system. Solving the deep discharge question is a matter of setting limits on battery discharge below certain levels - always leaving enough energy to meet the work day demand by the day start time.

The economics have a feasable model in place in the business/consumer renewable to grid formulas in use now. So the key seems to start with a fleet, wholly owned and operated under fixed charge station conditions. Sacramento can further justify the higher cost of BEV/PHEV vehicles by levelling and providing nighttime V2G flows from the PV banks. We could use a cost/kwH curve over 5,10 and 15 year battery evolution to better determine long term ROI.

The fleet implementation should help shake out the greater variables in a consumer model and better indicate the efficiencies of costs over time.

Anne, Patrick -

you rightly point out that a number of solutions to the data communications and transaction protocols already exist elsewhere and could be adapted fairly easily. This is correct, I merely wanted to underscore that V2G requires more than just the power infrastructure.

Joseph -

no-one is going to build a PHEV or BEV production vehicle unless both the technology and the economics make sense. The V2G concept is intended to address the currently poor economics of large battery packs by putting them to good use even when the vehicle is parked. If creating that infrastructure what it takes to make the economics work for series production, then it absolutely legitimate to think the concept through because multiple industries would have to conduct parallel R&D.

Any time you have to install any new stationary infrastructure, there is the chicken-and-egg question of how soon the market it serves can achieve critical mass. Getting oil companies and their gas station franchisees to switch from one liquid fuel grade or type to another is relatively straightforward yet the inertia that must be overcome is substantial. V2G would require a far greater investment from the utilities, so the business risk would have to be acceptable to them as well as to carmakers.

The "won't register for V2G" problem is easily solved:  have the car analyze its typical use-cycle and register and manage itself.  For PHEV's, this is easily done.

As for the "user won't plug in", people who don't want to get the discount from plugging in will be free to pay top dollar.

Thanks for stopping by!  It's great that you're actually reading comments by the hoi polloi.

I would not want to use any of my battery cycles for this, but an SOFC that wants to be run continuously would do just fine.

It's good to hear BP & GM talk about alternative fuels, but 50 years to implement is too long.

http://money.cnn.com/2008/03/05/news/companies/bigoil_hydrogen/index.htm

Perhaps this link will spark more attention:

http://www.chevrolet.com/electriccar/

It is GM's electric concept car the Chevy Volt. If more people begin to demand alternative fuel cars, we should be able to speed the rate at which the technology is developed.

We have started an Investor Forum where Investors can meet and discuss topics like this:

http://investor-forum.thesubway.com/