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Power Transportation Science

Use Your Car To Power Your House 271

itwbennett writes "Nissan has developed a system that allows a vehicle to supply electricity to power a house during a power outage or shortage. A prototype of the charging system running on a Nissan Leaf electric car was unveiled in Japan on Tuesday. A two-way charging device that would typically convert the household electricity supply to a voltage suitable for charging the car's battery can be reversed to feed power back into the household circuit."
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Use Your Car To Power Your House

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  • This [] guy did it years ago with his Prius. Trouble is, his electric utility is so reliable that he never gets to use the feature!
    • This guy [] actually used it during a power outage.
    • by vlm ( 69642 )

      There was a QST magazine article about half a decade ago about using the prius traction battery and what amounted to a VFD to provide emergency power. Which is nice, except for the Prius legendary HF RFI problem. You can hear a prius from quite a distance on the radio due to interference; the irony of providing emergency power for radio gear using a prius which interferes with the radios was not lost on many readers. I guess for the VHF FM only crowd it works pretty well.

      I cannot find the article in goog

    • Also, these guys [] have been advertising this as a feature of their system for near a decade. The only problem is that (last time I asked) they want $50k a pop for their motor controller.
  • not that simple (Score:3, Interesting)

    by meridien ( 718383 ) on Tuesday August 02, 2011 @10:32AM (#36959538) Homepage
    When the mains power is out (such as a storm or auto accident), the crews working on the problem will have the power for that grid shut off so that they can work safely. Any properly installed standby generator will have a solenoid that disconnects the house from the mains while the generator is supplying power. This is REQUIRED by national electrical code. Imagine the lineman's surprise when he touches wires that are disconnected from the generating station and SHOULD BE CARRYING NO CURRENT but are powered because some nimrod connected a standby system improperly. Not good.
    • My understanding is that you can't charge one of these from regular wall current but need at least 220V (It might be more) so if you were going to get the backup generator option you get the disconnect device kit as part of it as you will probably be installing new wiring any way to have one circuit with 220V on it this could be installed at the same time. Now if you were like my father who has several 220V circuits in his garage (one is rated to 50 amps) then the lineman may be in for a surprise but most p
      • Chevy Volt comes with a 110V charging cord. Of course, it takes ~8-10 hours to charge at that voltage due to current limits. the charging station you can install gives you 220V and supposedly cuts that to 3-4hrs. so it can do either.

      • My understanding is that you can't charge one of these from regular wall current but need at least 220V

        Nope, you can charge using 120 V, but it takes a lot longer. 120 V charging is defined as level 1 charging, while 240 V is level 2 charging. There's also a level 3 charging for very fast charging, which I think from memory is only being tested in Japan right now.

        Search on SAE J1772 for more details.

    • by mr1911 ( 1942298 )
      Or, if you manually connect your electric car, generator, or other backup power source, you also manually flip your main breaker so you are only powering your house. Otherwise, you will not get much utility out of your limited power source, would you?

      And on a side note, no lineman that intends to go home at night would ever grab a line assuming it was not live, would he?
    • by Rich0 ( 548339 )

      Yup, although I suspect that linemen take precautions just the same.

      At work they have some 33kV supply lines running 3-phase. They needed to do work on expanding the lines, and I noticed that the first thing they did was attach cables to short the three lines together using large fiberglass poles with tools attached (the lack of a spectacular display demonstrated that they had turned off the power successfully). The place I work is actually pretty anal-retentive regarding safety so the chance of a breaker

    • by Bengie ( 1121981 )

      Imagine the car owners surprise when his car is trying to power the entire neighborhood and the power inverter burns out in a few seconds.

      I'm sure they'll have some safety device.

    • by vlm ( 69642 )

      Its a nice story, and VERY popular to retell, but if the drop line fuse is not blown, trying to backfeed an entire subdivision will instantly stall the engine, if not burn out the alternator and/or blow the drop fuse.

      The actual failure mode is the drop fuse blows, the lineman tries to replace it, your generator happens to be out of phase with the national grid, and either the fuse pretty much detonates in the linemans hands, or the generator literally blows up, as in crankshaft sheared off and piston flys t

  • by Bob the Super Hamste ( 1152367 ) on Tuesday August 02, 2011 @10:36AM (#36959592) Homepage

    It doesn't surprise me much as I have heard industry rumors of doing similar things with the smart grid and basically using EVs as a storage medium. Yes I work in this industry so /. here say seems to be correct on this.

    As a side note I have also used a car to heat up the garage in the winter to work on it or just change oil. Basically you go and attach a vent hose (aluminum dryer vent works great) to your exhaust and route it out the door. Then start your vehicle and let it run for half an hour. In my uninsulated garage I can get the temp up near freezing from below zero (Fahrenheit). Once warm shut off the car and change your oil. If there is one thing a car engine is good at it is producing heat.

  • If you have a car with an electric source it is convenient to be able to direct the electricity where it is needed. I don't need an emergency generator often enough to own one, but it would be nice to be able to use my car that way. If the car can also be powered with gasoline, then it becomes more reliable in a likely emergency because it sometimes takes days to repair storm damage. I'm not intending to use it long-term, so I don't care how many miles per millimeter of tectonic movement I might be getti
  • by bre_dnd ( 686663 ) on Tuesday August 02, 2011 @10:37AM (#36959612)
    This is not as stupid as it sounds at first.

    The problem with generating electricity is that you can't (normally) store electricity -- so generating capacity is dimensioned for the peak load. A lot of excess capacity is available at night -- some of which you can't just shut off. It takes a long time to power up a coal/nuclear power plant. In mountainous regions the night excess is used e.g. to pump water uphill, back into a lake that is part of a hydroelectric plant.

    Charging the car at night when rates are low makes sense, and running a few lightbulbs or a TV set doesn't use the amount of power you need for driving.

    • The problem with generating electricity is that you can't (normally) store electricity -- so generating capacity is dimensioned for the peak load. A lot of excess capacity is available at night

      Yes and no. I suspect less excess is available than you might think. Excess capacity costs money, and utilities have spend decades either finding customers for that excess or finding ways to minimize it's generation or not generating it at all.

      running a few lightbulbs or a TV set doesn't use the amount of p

  • Penny drops (Score:5, Interesting)

    by arkhan_jg ( 618674 ) on Tuesday August 02, 2011 @10:39AM (#36959624)

    I did initially think 'Why on earth would you go to the trouble and inefficiency of this with an expensive electric car?' and then the penny dropped. It's in Japan, where they were having rolling brownouts due to the nuclear disaster and the loss of capacity, and are still under threat of blackouts over the summer.

    • No, there is absolutely no black or brownouts, it was considered at first, but once everybody was asked to stop wasting electricity with aircooling at full blast with windows open on every shopping mall the demand became actually 30 to 40 % lower than the year before. This with the fact that the summer is really cool compared to usual means that Tepco is FAR from being maxed out. Check the operation Yashima website to have data: []

  • by wisebabo ( 638845 ) on Tuesday August 02, 2011 @10:49AM (#36959786) Journal

    You know, this would be really really useful here in Vietnam where the extraordinary growth rate coupled with communist era bureaucracies/corruption has left power supplies lagging far behind demand. I would dearly love a generator I could use to power my abode when the power goes out (typically in the hottest part of the day which in Vietnam is pretty hot!). This is probably true of a lot of developing countries.

    Also in my previous career in the film industry having a powerful generator that is not only mobile but transports itself (and cargo and crew!) would be a godsend for shots not on the studio lot.

    • You know, this would be really really useful here in Vietnam where the extraordinary growth rate coupled with communist era bureaucracies/corruption has left power supplies lagging far behind demand. I would dearly love a generator I could use to power my abode when the power goes out (typically in the hottest part of the day which in Vietnam is pretty hot!). This is probably true of a lot of developing countries.

      Also in my previous career in the film industry having a powerful generator that is not only mobile but transports itself (and cargo and crew!) would be a godsend for shots not on the studio lot.

      But could most people in developing countries afford a Leaf? And, if they could, where would the extra power come from to keep recharging them? If the electrical infrastructure is not up to the task before adding a bunch of electric cars, how will it support them. This isn't something that applies to just 3rd world countries. California is concerned that their electrical grid cannot support wide spread adoption of all electric vehicles, too.

      Whether in a Nissan Leaf or a a dedicated storage pack, a batte

      • My bad, I thought the Leaf was a hybrid (like a Prius)! So you're right, having lots of Leafs (Leaves?) would make things worse not better. However that's for society as a whole which is usually the last thing on the average person's mind around here. :(

        As far as the affordability goes though, the wealth distribution in Vietnam is very bad. Lots of motorbikes but also some Mercedes, Bentleys and Maybachs. I figure anyone whose stolen... I mean made enough money to afford a car can afford a Leaf.

  • When we had 2 hurricanes hit here in N Fla in 2005 I did it with my Nissan Altima and 2 400 watt inverters I got from a car stereo store. No generators to be found *anywhere*, I had myself my wife a 3 year old and a newborn to worry about.

    One inverter kept the fridge and freezer going, the other ran a few flourescent shop lights and some low wattage fans.

    No power for 10 days, had power back for a week, then no power again for 7 days. Didn't live in luxury, but we were mostly comfortable in the evenings an

  • This would be a dream come true for amateur filmmakers who need a power source for filming outdoors at night. Portable generators are either too noisy or too expensive. You can get an inverter for your car to supply 120V AC, which is a decent solution because cars aren't very noisy, but energy from a battery makes no noise at all, and sufficient energy for powering a house for a day certainly can handle 2000 watts of light for a night shoot. Amateur filmmakers normally have a day job, so they can afford
    • by vlm ( 69642 )

      the pros mostly use those loud generators on the other side of the trucks with "welding grade" extremely heavy gauge extension cords.

      Just sayin, in case you wanna try it on the cheap, you don't need to buy a new car, just some (expensive) extension cords.

      The "rave" guys did the same for their audio. That's how I know. In that case, once the subwoofers get louder than the gens it doesn't really matter, I suppose.

    • Amateur filmmakers can afford a $35,000 compact car, but not a $5,000 generator? (Honda's 6500 watt, 52 db model)
  • So I've been thinking about this a little and here's a couple of drawbacks I see:

    1. Assuming you're using a pure electric car, using your car to run your house means it has no charge the next morning so you can't get to work.
    2. If you come home at the end of the day with a mostly depleted charge in the batteries, The car won't be able to supply much power to the house before being completely dead.
    3. You could use a gas/electric hybrid like the Volt or Prius to run this type of system. However, the charging system
    • by Arlet ( 29997 )

      The charging/generating circuit won't be able to power the whole house.

      On the contrary. An electric car has much more power than the typical house. Accelerating a 1 ton mass to 65 mph in 15 seconds takes 50 kilowatts. You can turn on all the appliances in a normal house and not get close to that.

      • by Arlet ( 29997 )

        Forgot a factor of 1/2 in there. It takes 25 kilowatts. Still, plenty to power a house.

      • Oh, the batteries certainly have the juice to do it. However, the charging circuit can't handle that amperage. I suppose if you attached a monstrous inverter directly to the batteries, you could possibly do it. But the charging station you put in most houses in Japan and the US can only support maybe 30 amps at 220/240v. That's a couple of circuits for lights and the fridge and you're tapped out. If you're using the standard household plug circuit, that's only 12 amps at 110v. That's not enough to run

        • by Arlet ( 29997 )

          Supposedly Nissan has developed a new charger that can be used for this purpose.

          With modern electronics, the inverter doesn't need to be that monstrous. Similar kind of power electronics is needed inside the car to control the motor(s) already, and I'm sure it's not monstrous. And 30 amps at 220V is more than you need for a few lights and a fridge. A fridge is something like 300W. That's only 1.5 amps.

      1. Grid reliability. I live in an area that has more than enough capacity and a grid that stays up over 99.9% of the time. Sure, there are some people who don't have this luxury. And that's certainly a driving force for some people to want a backup. But most suburban dwellers in first world countries (the type who are the most likely to drive a Leaf in the first place since you need a grid like that to be able to rely on a purely electric car) share my luxury of a stable grid. When the grid is (almost) always operating just fine, why do you need to have a backup?

      If you live in the US, you may be overestimating your grid reliability--it's not what it once was. With increasing automation, secondary distribution grids have become very good at rapidly isolating individual faults, so that their impact is minimal. However, that same design makes them vulnerable to multiple faults. When a natural disaster causes damage in many locations, the grid operators have to take down the entire system until everything is fixed. That can take one to two weeks, leaving tens of th

      • I don't doubt that. But the chance of that actually happening is still very low. Sure, it may start to get worse over the coming years. I have no doubt it will given how little this country spends on infrastructure maintenance. But here's the thing. Grid reliability is the only thing that lets people rely on electric cars. If the grid starts crashing more often, the draw for pure electric cars will vanish and most people won't buy them. Why buy a car that you can't reliably charge? The very thing th

    • Using the leaf battery pack, I show it having 24kwh of capacity that will run my house for a few hours. Not massively useful that's only marginally better than the 5kw gen that will run my whole house save the electric drier.

      Depending on the hybrid they can be efficient generators. The battery pack actually helps as it can run at max efficient output and charge the batteries with the excess and cycle on and off. This is one of the big potential advantages for hybrid work trucks.

      Cost of operation is gener

      • A 240V, 30A circuit won't feed as much as you might think. That circuit could feed four 15 amp 110 circuits. That might power your fridge, several lights and maybe a TV. Forget an electric cooktop (usually a 220V, 50A circuit). Though you may be able to get away with just one burner. No way can you run your A/C system. Electric heat? Not a chance. You'd probably have to choose between running the gas powered furnace and the television (a hard decision for some I know).

        30 amps just doesn't cut it for

  • ... if this technique could save you so much money by shifting your power consumption to off-peak hours and providing a good backup power source during outages, then the car just seems like an unnecessary middleman. why not just have the battery cell and power converter tucked away in your garage, happily charging at night and dispensing during the day and clicking on when the mains disappears?
    • Residents are not* billed hourly rates, just daily rates at the most, eliminating the rationale.

      Businesses are billed minute or hourly, so it makes sense for them, but they consume way more than the battery can put out, eliminating that rationale.

      • by Arlet ( 29997 )

        I have a double meter in my house. The electric company puts a special pulse on the line, once at night, and once in the morning, that makes the meter switch from one counter to another.

        You can choose between several tariff plans. You can have them switch the meter in the evening, or you can have them switch at night, or not switch at all.

        These meters are very common around here.

    • Because batteries have a limited shelf life. The power you'd use from this system is very expensive due to the wear you'd incur on the battery pack. There is also a loss involved in charging the battery and the inverter is only 80-90% efficient at best. Some people utterly cannot live without the ability to use the lights, TV, hair dryer for the few hours a year the power might go but for most it's not worth the added expense. You don't need a fancy hybrid or electric car either, just plug a cheap square
  • My car is my home, you insensitive dolt.
  • Good idea if you have an electric car. But backup gas powered generators are a few hundred dollar to a couple of grand at your local hardware store.depending upon power output.

  • by cavehobbit ( 652751 ) on Tuesday August 02, 2011 @11:37AM (#36960424)
    If you just try to plug this into a wall socket, you could feed electricity out of your house into the power lines people are working on. Something that idiots installing home-center purchased generators have been known to do. This is why when power generators are properly installed, they use cutoffs and safety switches between the house and the main utility meter to prevent back feeding power into the grid when nothing is coming in. Anyone that does this should only run a line from the car to an outlet strip to power a few critical items, unless a proper system is installed and inspected to prevent that back-feed.
    • Not to mention, that I don't want to be trying to power the entire neighborhood from my personal generator. I would like to hope there are regulations that ensure a properly licensed person would be connecting a system like this, so the proper safety features are enabled. The 2 problems with this are:

      #1 There are a lot of asshats out there that will try to connect something like this themselves and bypass safety features.
      #2 There are licensed electricians that are asshats too.

  • I used my truck to supply power for my house when Hurricane Isabel came through and knocked out the grid for the better part of a week. It makes sense, given the energy capacity of the battery in an electric vehicle, to consider them as an option for emergency backup power.
  • If you had a hybrid -- of the type that uses an internal combustion engine only to run a generator to charge up its battery -- that would also be capable of feeding its power back into the household circuit, then you'd be able to power your house for even longer.
  • At first thought, this seems to be a good idea but precautions must be followed. How many people will use this system without making the necessary alterations to your house circuit box? I had an emergency power generator and made the needed changes to disconnect the house from the power companies lines when the generator is being used. Without these changes, the generator (or electric car) will push the electricity out to the power grid. What a lineman (repairing downed wires) considers to be a dead wir

"This is lemma 1.1. We start a new chapter so the numbers all go back to one." -- Prof. Seager, C&O 351