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Transportation Power Technology

Electric Cars to Help Utilities Load Balance Grid 247

Posted by Zonk from the little-bit-here-little-bit-there dept.
Reservoir Hill writes "A team at the University of Delaware has created a system that enables vehicles to not only run on electricity alone, but also to generate revenue by storing and providing electricity for utilities. The technology, known as V2G, for vehicle-to-grid, lets electricity flow from the car's battery to power lines and back. When the car is in the V2G setting, the battery's charge goes up or down depending on the needs of the grid operator, which sometimes must store surplus power and other times requires extra power to respond to surges in usage. The ability of the V2G car's battery to act like a sponge provides a solution for utilities, which pay millions to generating stations that help balance the grid."
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Electric Cars to Help Utilities Load Balance Grid More

Electric Cars to Help Utilities Load Balance Grid

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  • Make money from your car? (Score:3, Interesting)

    by timeOday ( 582209 ) on Monday December 10, 2007 @12:34AM (#21638291)
    Next up, plug your hydrogen car [nytimes.com] into the grid as a generator. Don't bother pointing out that all this conversion will lose some efficiency; of course it will. But think about the brownouts California was suffering a few summers ago. People will pay good money to escape no air conditioning, and some transmission loss doesn't change that.

    • Re: (Score:2, Informative)

      by AuMatar ( 183847 )
      The brownouts we're mainly hot air. First off, very few actually happened. Secondly, they were artificial- caused by manipulations of the power grid by energy providers for profit. There was no energy shortage.

      • Re:Make money from your car? (Score:5, Informative)

        by Technician ( 215283 ) on Monday December 10, 2007 @02:32AM (#21639003)
        The brownouts we're mainly hot air. First off, very few actually happened. Secondly, they were artificial- caused by manipulations of the power grid by energy providers for profit. There was no energy shortage.

        Bzzzt... Wrong.

        The energy shortage was real and localized. In the Enron days, California capped electricity rates as a consumer protection move. As a result, Enron in a move to cut losses from expensive generation and as a leverage tool to negotiate new rates, took the oppertunity when fuel prices spiked to shut down a lot of ineffecient generation plants for maitenance. This was followed by a heat wave which put a spike in demand for AC. A line tripped offline. It was either blackout time as systems cascaded carrying the overload or simply drop part of the load and leave the rest of the sytem up.

        http://tdworld.com/mag/power_world_technology_update_2/ [tdworld.com]
        "California Energy Crisis Reaches Stage Three Electrical Emergency Already under a Stage Three Electrical Emergency due to scant resources, the California Independent System Operator (California ISO) encountered a significant and sudden loss of transmission capacity Jan. 21, 2001, that forced municipal utilities in Northern California, U.S. to endure a brief 20-min transmission-related outage."

        "The California ISO issued the controlled outage to keep the ac lines from overloading at Path 15, a group of high-voltage lines in central California already at their limit because of low resources in the northern part of the state."

        There was a blackout because there was not enough in area generation online. The capacity of the system was stressed. A line failed. The already loaded lines couldn't take on the replacement load. Part of the area was shut off to preserve the remaining area. It was small blackout time of watch the entire area go dark as the system collapsed.

        http://en.wikipedia.org/wiki/California_electricity_crisis [wikipedia.org]
        "Due to price controls, utility companies were paying more for electricity than they were allowed to charge customers forcing the bankruptcy of Pacific Gas and Electric and the public bail out of Southern California Edison. This led to a shortage in energy and therefore, blackouts. Rolling blackouts began in June 2000 and recurred several times in the following 12 months."

        "Energy price regulation forced suppliers to ration their electricity supply rather than expand production. This scarcity created opportunities for market manipulation by energy speculators."

        If you need any more proof that price controls cause shortages, just re-read the above. You can mandate $1/gallon for gasoline, but don't expect to find it for sale anywhere.

        Read between the lines.. they didn't pay high prices for fuel for ineffecient plants.

        "Despite the action, PG&E said it still is having trouble getting gas suppliers to comply with the emergency order originally issued January 19. PG&E has said it has enough gas in storage to make up for the lost supply under such a scenario until the first week in February. According to a company spokesperson, PG&E's storage currently is well below 50% full, or less than 16 Bcf and depleting rapidly by about 500 MMcf/d to 1 Bcf/d."

        They used their reserve fuel, but could only buy fuel at a loss due to price caps and high fuel cost. Gas suppliers were not selling below market. They sold at market rates, a price the utilites could not afford.

        Expensive to run generation plants were shut down for upgrades and maitenance while they waited out the high fuel prices. The spike in demand caused the inevetible. The lines into the area could provide only part of the cheaper power from elsewhere.

        http://www.usbr.gov/dataweb/html/pninter.html [usbr.gov] This is the list of the lines from Oregon into California and their capacities.

    • Next up, plug your hydrogen car into the grid as a generator. Don't bother pointing out that all this conversion will lose some efficiency; of course it will. But think about the brownouts California was suffering a few summers ago. People will pay good money to escape no air conditioning, and some transmission loss doesn't change that.

      But why would you provide energy for the grid ? Disconnect the house and use the electricity yourself. The power company can't sell electricity for more than it costs to

      • Re: (Score:2)

        by repvik ( 96666 )

        The power company can't sell electricity for more than it costs to produce it yourself that way, because then no one would buy it, and they can't pay you as much or more than they get when selling it, because then they'll go banckrupt.

        Of course they can pay you much, much more than they sold it for, they're not buying a lot. In the long run, that costs them less than a brown/blackout, even if they pay you several hundred times what you paid.
        • Electricity might be at a premium rate during the evening - when your car might provide it. Also, assuming that you are in a state that won't let you build coal plants and that the incoming power lines are already over nominal, the electricity company simply has no other way to get energy. Building a gas-fired generator is costly, takes a bit of time, and the electricity it generates is expensive (fuel costs).

          • Electricity might be at a premium rate during the evening - when your car might provide it. Also, assuming that you are in a state that won't let you build coal plants and that the incoming power lines are already over nominal, the electricity company simply has no other way to get energy. Building a gas-fired generator is costly, takes a bit of time, and the electricity it generates is expensive (fuel costs).

            In order to get anything out of this arrangement, the fuel cost per kilowatt produced must be l

  • Oops (Score:4, Interesting)

    by Power_Pentode ( 1123285 ) on Monday December 10, 2007 @12:38AM (#21638323)
    Wait until everyone leaves on holiday some unusually hot 4th of July morning. The earlybirds are fine, but those leaving later have empty "tanks" because ConEd sucked out all their battery power to run all of the air conditioners.

    • Re: (Score:2)

      by Orne ( 144925 )
      Utilities are required to keep a capacity reserve to meet the 3-year ahead projected demand for electricity. The electric car resource (like a windfarm) is considered energy-only -- because of its unpredictability, it cannot be considered capacity.

      What's even better is that all of this capacity is built for that 3 hour period in the summer when it's 99F out and everyone is running their air conditioners at full tilt.

      The difference that this technology makes is price. Would you rather be paying a utility t

    • Re: (Score:2)

      by rossdee ( 243626 )
      On holidays people typically drive longer distances, so they will take the hybrid rather than the elctric ar they use for commuting. - and they'd be towing the boat, carrying all the kids and the dog, and their stuff, so they would need the SUV anyway.

  • AC Propulsion (Score:4, Informative)

    by TheMiddleRoad ( 1153113 ) on Monday December 10, 2007 @12:38AM (#21638327)
    AC Propulsion, who built the car, has been working on this technology for quite a long time. Their press release is at http://www.acpropulsion.com/releases/10-24-2007.htm [acpropulsion.com]. They also have a solar powered, unmanned aircraft, an electric sports car that long precedes the T-Zero, and good taste in car bodies since they've used the Sportech and xB for their major projects.
    • The author of some of the literature was Alexander Brooks, someone I knew from high school and UC Bezerkeley. Alec's degrees were in Civil engineering, not electrical engineering, and I found quite a few points where he would have done well to consult more with the power systems crowd - and a specific recommendation would have been to consult with Prof O.J.M. Smith of UCB.

      A real simple control method is to pay attention to frequency - go from charging to feeding back when the fequency drops below nominal

  • Battery Life? (Score:5, Insightful)

    by corsec67 ( 627446 ) on Monday December 10, 2007 @12:41AM (#21638349) Homepage Journal
    Most batteries have a nominal number of charge/discharge cycles that they can go through before they can't hold any capacity any more.
    Why would you wear out an expensive, hard to dispose of part of a car like that?

    (Unless the cars use Supercapacitors [wikipedia.org] or a high-speed flywheel [wikipedia.org], in which case the only issue is transformer/inverter losses, which might be balanced by transmission losses if the usage is near to the car, in which case this could be a good idea)

    • Re: (Score:2, Insightful)

      by Leuf ( 918654 )
      If it were actually economical to do this, then why wouldn't the utilities just buy the batteries themselves rather than pay you to use yours?
      • Yeah, what is the different between these cars and a UPS-like device in every garage? If this was really good for the power company then they would give people a discount for putting a battery-inverter thing in their house, properly connected...

        • Re: (Score:2)

          by Duhavid ( 677874 )
          Maybe because this way the power company doesnt have to give any discount?
          Heck, they will probably charge the recipient of the power and the
          car owner for this "service".

      • Re: (Score:3, Insightful)

        by evanbd ( 210358 )
        Well, if it's not economical to buy the battery for the purpose, but you're going to buy the battery anyway to use it in the car... A lot of batteries (especially LiIon) have a significant component of their lifetime measured in years of service, not charge cycles. So if it's not costing you anything to use the battery like this, and you already own it...
    • Comment removed based on user account deletion
      • Problem 1: have 2 flywheels, going in opposite directions.

        Problem 2: the flywheel has about the same amount of energy as gasoline a car normally carries, right? Just make the flywheel out of something that breaks in to a ton of little pieces that gets caught by the container (as suggested by the wiki article) Anything that is energy-dense is going to have this problems, like Sony Batteries, gasoline, etc.

        Yeah, high-speed flywheels are a long way off from being usable to run a car, but one of the biggest hur

    • Re: (Score:2)

      by evanbd ( 210358 )

      For Lithium Ion batteries, most of the lifetime of the battery is determined by time since manufacture (with modifiers for how charged it is -- 40% or so is best, iirc -- and temperature and such), with charge cycles being a second-order effect. Of course, that assumes you take good care of it, but the charge controller in the car should be able to handle that anyway.

      Of course, as you say, supercapacitors are the interesting technology. AIUI, all the pieces exist in the lab to make supercaps that beat L

  • So then... (Score:4, Funny)

    by LOTHAR, of the Hill ( 14645 ) on Monday December 10, 2007 @12:42AM (#21638353)
    It's like a giant Carpacitor!!!

    It's only really useful if it can store 8.6 jigawatts!

  • Better ways to balance load (Score:3, Interesting)

    by Jeff1946 ( 944062 ) on Monday December 10, 2007 @12:47AM (#21638383) Journal
    Probably lose 10% of power charging and 10% discharging if you are lucky. You want your car in the daytime when loads are heaviest. Must not put power on lines when linemen are working on them. Pumped hydroelectric is much better and currently used to store power. Always thought wind powered generators near a pumped hydroelectric would be a good thing. Also large windfarms in places like west Texas generating hydrogen would also be a reasonable thing to do. When we run out of natural gas, the existing gas distribution system could be used to pump the hydrogen all over the country much as we do with natural gas today.
    • Pumped hydroelectric is great where it's available, sure, but what would, say, New York City do? Pump out New Your Harbor?

    • Re:Better ways to balance load (Score:4, Insightful)

      by edwardpickman ( 965122 ) on Monday December 10, 2007 @01:07AM (#21638539)
      Natural gas lines are't suitable for hydrogen. It's the smallest atom so it tends to leak from most any seal. Part of the problem with hydrogen is storage and distribution because of leakage. If you leavea full tank of gasoline for a year it's still full. Even the best hydrogen car storage system would be empty long before the year is out. If you are driving constantly the loss would be manageable but even leaving it overnight would result in some loss and a weekend might see a noticeable drop in tank pressure. I love hydrogen but it seems best suited for short term storage and it's strictly a storage medium and not a true power source. I think it's better suited to home storage system of power for solar and wind and recharging electric cars. Even the hydrogen cars that are being proposed are in truth electric cars they just use hydrogen instead of batteries. I've never heard of a hydrogen car getting 200+ miles on a tank like some of the latest electric cars using batteries. Recharge times are the biggest problem but that's strictly for long range travel since most people see home recharging as a plus with electrics. Capacitors may eventually solve this problem. Either way electrics if the cost of batteries came down would still work for 90% of the driving and even at current prices they are radically cheaper than hydrogen fuel cells. Platnium is going to keep the costs high. Electric is practical today and works with or current infrastructure. People complain about costs and range on electric cars I can't see them accepting hydrogen cars that cost many times as much and have a range of a 100 miles. Nano processes may drop the amount of platium needed but it will still be expensive and the storage problems still exist. You still need an energy source to produce hydrogen so there is no real difference between it and electric cars.

      • Re:Better ways to balance load (Score:5, Informative)

        by wvmarle ( 1070040 ) on Monday December 10, 2007 @02:27AM (#21638973)

        Natural gas lines are't suitable for hydrogen. It's the smallest atom so it tends to leak from most any seal.

        Hydrogen is small, but hydrogen always comes as an H2 molecule, and that is not quite the smallest gas particle. Helium is the smallest gas particle: the smallest of the noble gases, and it comes as single atoms. Leak tests are always done with He. If He doesn't leak, then nothing will. A nice extra is that He is virtually absent from our atmosphere, so any trace amount He found indicates a leak.

        That said, it is certainly true that sometimes methane does not leak where H2 does. However this can never be in large quantities, as otherwise the methane would also be leaking already. I don't know whether this is a really significant problem with the existing gas network.

        Much more likely an issue I think is hydrogen fatigue: many metals become brittle when exposed to H2 gas over a long period of time, and break. This is a serious issue in the design of chemical reactors, surfaces that are exposed to H2 can not carry any pressure load (so they build a second vessel around it, that carries the pressure, the gap filled with another gas such as nitrogen).

    • Re: (Score:2, Insightful)

      by Nqdiddles ( 805995 )
      Well, I don't actually need my car ALL day. I've seen scenarios described where the vehicles could be plugged in at home, then again at work (while you're in the office and not using it).
      Planning the controls on the system would require a fair bit of effort/balancing, but it could be worth a look.
      If perhaps the manufacturer (or power company, or someone else)"leased" the batteries to you, or otherwise minimised the effect of the increased use on your hip pocket, and allowed for user customisable minimum c
      • Would it be better if power was generated at work perhaps a big wind turbine, you could designate part of the car park to these types of vehicles and use the car park as one big ups. If enough power was generated you could use it at home as well.

        Then there are the carbon offsetting taxes since hopefully you would be generating a surplus most days. On days you didn't you would pull it back from the cars. Assuming a 400 mile range and most people would be commuting in less than 10 miles each way you could pro

    • Re: (Score:2)

      by Chrisq ( 894406 )
      You want your car in the daytime when loads are heaviest. Must not put power on lines when linemen are working on them.

      True, but it could be a lot more efficient if your work's parking lot allowed you to plug in. Some companies could even use the power directly to reduce their peak workday load (for example where I work most people turn their computers on after arriving and turn them off before leaving). This would also have the advantage that they would only need to leave enough power for half your comm

    • Re: (Score:2)

      by necro81 ( 917438 )

      Pumped hydroelectric is much better and currently used to store power. Always thought wind powered generators near a pumped hydroelectric would be a good thing.

      Unfortunately, the places where wind energy is a great resource generally aren't great places for pumped hydro storage - geographically speaking. Wind energy is most available and steady in large flat expanses - the American midwest, near shore ocean, etc. Pumped hydro storage is most available in places that have large natural height differences

  • Down-sides (Score:5, Funny)

    by Tablizer ( 95088 ) on Monday December 10, 2007 @12:53AM (#21638437) Journal
    Computer voice: "Sorry, you cannot go to Vegas this weekend, we need your batttery."
  • I'm sorry but you can't use your car to go out this weekend. We need power to go to the grid. Try again next weekend, or apply for our weekend special at www.yourcarhahaha.com. Have a nice day.
  • Okay, this didn't make a lot of sense to me at first, thinking that electric cars are the last things in the world to be providing excess power to the grid... But in fact, it is a neat idea.

    Basically, all of the batteries of these cars, connected to the grid, act as a bit of a buffer/reservoir of power for the grid. Think water tower, where water is stored there temporarily, to be pulled out during times of peak demand. Similarly, the batteries of these cars (presumably only a portion of them) provide so

  • photovoltaics (Score:3, Interesting)

    by bcrowell ( 177657 ) on Monday December 10, 2007 @01:05AM (#21638527) Homepage
    If the utilities really want help balancing the grid here in California, they should change how they handle photovoltaics. I have photovoltaics, and there's a strong disincentive to buy more than enough capacity to handle 80% or so of your annual use. If you overproduce over the course of a 12-month billing period, they just take your extra electricity for free, and say thank you very much. If they would pay for excess production, I'd have a strong incentive to add more panels on my roof, and those panels would produce a lot of electricity on those hot Southern California days when everybody's using their AC.
    • It really depends region to region. In northern Illinois, with ComEd, we have net metering. When we use power, the meter spins forward. When we dump unused generation capacity into the grid, our meter spins backwards. Typically, most people have a small electric bill if they have a wind turbine or solar panels. Those with much larger systems may have credits for most of the year with the utility.

  • Offloading costs more like it. (Score:5, Insightful)

    by SeaFox ( 739806 ) on Monday December 10, 2007 @01:18AM (#21638613)

    The ability of the V2G car's battery to act like a sponge provides a solution for utilities, which pay millions to generating stations that help balance the grid.


    So since I'm now taking over that job, how much will my cut be?

    I thought so.

    And this wont have any impact on the life span of my car's expensive battery will it?

    Oh, it will.

    Well since they're now saving so much money, they'll be able to lower utility ra---
    What's so funny?

    • Re:Offloading costs more like it. (Score:5, Informative)

      by evanbd ( 210358 ) on Monday December 10, 2007 @01:43AM (#21638767)

      You do realize that this already happens, and the electric companies do pay you for it? Industrially, power compaines give large consumers a break on rates if they get a say in when the power gets used, for exactly this reason. Some consumers need fairly large amounts of power, but don't care when they use it. Think refrigerated warehouses -- you can turn off the refrigeration for hours to reduce load without trouble, but then they have to use more later. In exchange for doing this, they get reduced rates. In some areas, you can also buy time of day metering -- handy if you have grid-tie solar panels, as you get to run the meter backward at day rates, then come home and use power at night rates.

      I imagine they would be happy to extend the same basic deals to your car. And as you point out, you're not required to do so, so if they want you too, they'll have to offer such things.

      • Re: (Score:2)

        by Bert64 ( 520050 )
        Some countries provide this benefit to consumers as well, making electricity cheaper during a specific period (usually late at night)... People set power hungry appliances like water heaters, dishwashers, washing machines etc to come on at these times.
  • Won't a technology like this put the battery through excessive charge / discharge cycles, killing battery life?
    • Depends on the charge/discharge amount. Most hybrid batteries are never charged past 70% of full capacity, and never discharged past 40% of full capacity. This greatly extends their life (although, that's specific to the hybrid synergy drive in Toyota and Lexus hybrids using NiMh batteries. Lithium Ion batteries are much more friendly to full discharge, but need a more complicated battery management system)

  • Yeah. Right. Sure. (Score:2, Insightful)

    by mbstone ( 457308 )
    So the electric co. will buy the electricity in your car battery (at wholesale prices). Then when it doesn't need the power anyore, it recharges your battery (for which you are billed retail). Do this several dozen times a day and watch your bill skyrocket.

    • Re:Yeah. Right. Sure. (Score:5, Informative)

      by evanbd ( 210358 ) on Monday December 10, 2007 @01:39AM (#21638741)
      Umm... no? Right now, you can already do time of day metering, where you get charged different rates at different times. People with solar installations like this, because their solar panel returns power to the grid at daytime rates, and then they come home at night and use power at evening rates. You could do that with a battery too, except that batteries are expensive so no one does. Unless you already happen to have the battery...

    • So the electric co. will buy the electricity in your car battery (at wholesale prices). Then when it doesn't need the power anyore, it recharges your battery (for which you are billed retail). Do this several dozen times a day and watch your bill skyrocket.

      My parents have a solar cell installed on their roof, subsidised by the government (they live in The Netherlands). On a good day, if they do not use any electricity, they should be able to see the electricity meter run backwards. I can imagine that is the same in this case: if electricity is withdrawn, the meter runs backwards. So no billing would be done at all for that stored electricity, and it doesn't cost the user anything.

  • But... (Score:2)

    by Vskye ( 9079 )
    I bet fireman hate this concept, since if you have a fire and kill the power, the car would still feedback juice into the house. Friend of mine had his house burn down a few years ago, and they specifically asked him about a UPS.. Just something else to think about.
  • "The ability of the V2G car's battery to act like a sponge provides a solution for utilities, which pay millions to generating stations that help balance the grid."

    Yeah, it costs millions with whatever system they currently use (I'm guessing shipping the power to neighbouring power grids). How much will configuring tens of thousands of (currently non-existent) electric cars to take and feed the grid cost? How much is fixing all the meters so that they read properly in "generator" mode? Who wants to valid
  • Two key notes 1. Expensive, high energy storage devices will be developed for practical electric cars. The actual technology might be flywheels, ultra-capacitors, or some type of super battery. Point is, that's a huge investment in energy storage that shouldn't go to waste. 2. It's not as inefficient as you might think - the power released would not go far, probably just to help power the suburban house/apartment building that the car owner is plugged in to. 3. This technology would dov

    • Re: (Score:2)

      by XaXXon ( 202882 )
      isn't putting a power-storing flywheel in a car a bad idea? It would have to be light and spin extremely quickly.. but if it were fixed to the car, it would make the car hard to turn. I guess you could "float" it and let it spin regardless of the orientation of the car? Wow I don't want to get in an accident with one of these cars, though.
  • Cars? You kids want to use cars to drag your stinking electricity all over the neighborhood? When I was your age, I'd carry two buckets of electricity, uphill in the snow both ways.

    Now get off my lawn.
  • So, apparently we need a complicated system of grid feeding substations (electric cars, in this article) to help keep the grid working. Here's another idea - the utilities could do THEIR job a little better, and this vast infrastructure change will be irrelevant. How do they handle solar, wind and similar at the moment? Another issue is that overall power quality will degrade with too many cheap substations feeding energy with uncontrollable amounts of reactive power into the grid. Sure this can be handled,

  • Some (nearly) facts... (Score:3, Interesting)

    by DamonHD ( 794830 ) <d@hd.org> on Monday December 10, 2007 @04:31AM (#21639619) Homepage
    Well, there's been a lot of heat and little light so far...

    I've actually been exchanging emails with the UK's National Grid on a very similar topic: if I add some extra batteries to a grid-tie/UPS solar PV system, are they interested in it for frequency/fast standby support? Nominally I could automatically switch it on in one cycle to pump back at maximum for 30 minutes or more, which meets several of their key requirements. (See towards bottom of this page: http://www.earth.org.uk/saving-electricity.html [earth.org.uk] under From Net-Zero Electricity to Negative-Carbon.)

    So, I'd get paid for the electricity AND for providing a standby service to help grid stability.

    1) Even if you don't cycle batteries they still have a finite life: use them or loose them.

    2) You could easily set your system so that if the batteries are below 90% charge you won't support the grid: you'd hardly ever notice diminished capacity and you'd still be able to make a significant stability and peak-shaving contribution, and you'd also avoid deep-cycling for the grid which would wear them out faster.

    3) You avoid frying linespeople in a power cut with a system approved to G83/1 or similar: this is old tech.

    Rgds

    Damon
  • hey, great, my car is now a mobile uninterruptable power supply, so if there's a threat of a power outage taking out my home computers, I have to make sure I rush home and plug the car in!
  • If it wasn't for the cost it is perfectly possible to build plants that use biomass, hydroelectric, nuclear etc... that can rapidly adjust their power output. Hydroelectric plants can change their output close to instantly, for plants using turbines it is just a matter of how rapidly you can adjust the turbine speed, and while the most efficient turbines can only be adjusted slowly, you could easily use a few plants at slightly lower efficiency for load balancing ( as is done in many gas fired plants ). He

  • A question (Score:2, Interesting)

    by ko9 ( 946154 )
    How is this different from http://www.google.org/recharge/ [google.org] which I read a while ago? Seems like it's pretty much the same project.. But maybe there are subtle but important differences that I'm overlooking?
  • In addition to technological issues involved (battery fatigue, grid coupling, etc.), how many people are going to be willing to gamble this way with their means of transportation?

    It's like having a $random amount of gas in your car every day and (here's the kicker) not being able to top it off quickly. Now, many people people would never be caught by this, as they "never" drive more than 20 miles a day or something. Never say "never".

    For many other people all it takes is the supposition that there could b

  • let's get some facts straight (Score:5, Interesting)

    by loshwomp ( 468955 ) on Monday December 10, 2007 @01:36PM (#21645309)
    Disclaimer: I worked on some of the software in the vehicle mentioned in the article. The article was a little light on technical details. Dr. Kempton is much more qualified to comment with respect to V2G technology, but I'll try to preemptively clear a few things up, here.

    Why would I let the big bad utility company wear out my expensive battery?

    Because they'd pay you more than enough to make it worthwhile. The details of the business model are undefined, but as TFA explains, there is a lot of money on the table (at least $4K/year), so there is considerable financial incentive to put a fleet of vehicles to use. The basic idea is that a vehicle owner would sign on with an aggregator, who would control a fleet (thousands or hundreds of thousands of vehicles) and sell regulation services to the utilities at the megawatt level. It could be that you'd lease your battery from the aggregator.

    The most-valuable proposition is called ancillary services. Very simplistically, in this model you're not really moving much energy; you're really just selling the availability to provide fast-reacting regulation. Grid operation is a giant, complicated balancing act -- balancing generation with load.

    Right now the balancing is done by ramping generator output up and down. As greater amounts of solar and wind make their way into the power mix, generators will end up doing even more regulation. Unfortunately, generators are generally least efficient and most polluting when ramping, so a fleet of vehicles that can provide small amounts of regulation within milliseconds is extremely attractive to grid operators.

    But what if the utility company drains my battery when I need it for that long trip?

    Obviously the system would have to be designed to take your individual driving needs into account. The good thing is that it doesn't really matter what you do as an individual -- the statistical behavior of the fleet as a whole remains predictable.

    Furthermore, with a sufficiently large fleet of vehicles, it's possible to provide all the necessary regulation just by charging. If a vehicle is charging at 10kW, but is capable of charging at 20kW, then it can adjust its power up or down by 10kW, subject only to the constraint that it needs to be full by morning (or whenever). I've seen estimates by people more knowledgeable than I that we could regulate all of California with a fleet on the order of hundreds of thousands of EVs.

    If you're doing all your regulation via charging, then you can't claim you're wearing out your battery prematurely (unless you were never planning to charge it again, of course).

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