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Use Your Car To Power Your House

CmdrTaco posted more than 2 years ago | from the because-you-can dept.

Power 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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271 comments

Inefficient (-1)

bluefoxlucid (723572) | more than 2 years ago | (#36959492)

This looks stupidly inefficient. Either the car takes too god damn much energy to run; it has too huge of a battery; or it can't power a whole house for long.

Re:Inefficient (1)

bluefoxlucid (723572) | more than 2 years ago | (#36959504)

If the system is used regularly, it could also help cut energy bills. By charging the car overnight, when power demand is low and electricity is cheaper, the stored energy in the battery can be released in the daytime when electricity costs are higher.

Let's try this again...

If the system is used regularly, it could also help cut energy bills. By charging the car overnight, when power demand is low and electricity is cheaper, the power demand at night drastically increases above and beyond the power demand during the day, bringing the grid to its knees and driving up night time prices.

Re:Inefficient (3, Insightful)

rrossman2 (844318) | more than 2 years ago | (#36959576)

Lets try again:

If used regularly, the batteries in the leaf will need to be replaced a lot sooner than if this system wasn't used at all, which will add a significant price to the setup

Re:Inefficient (0)

Anonymous Coward | more than 2 years ago | (#36959648)

You have to keep in mind, the majority of our electricity use occurs during the day. Since power plants aren't things that you can just switch on and off on a whim, that means there's significant power generation at night that goes unused. Being able to tap that currently-wasted electrical potential and return it to the grid when it matters would allow us to run the grid more efficiently. Even if you ignore that possibility, it still means that a lot of EVs can be charged at night without disrupting the grid. Factor in the gradual uptake of EVs by consumers, and we are far from the catastrophic scenario you are envisioning.

Re:Inefficient (3, Insightful)

Lumpy (12016) | more than 2 years ago | (#36960040)

Or do what most electrical companies do, build a power reservoir.

http://en.wikipedia.org/wiki/Ludington_Pumped_Storage_Power_Plant [wikipedia.org]

Problem is a LOT of power is lost in the process, Just like using the car battery or even a dedicated battery would.

Re:Inefficient (1)

Hylandr (813770) | more than 2 years ago | (#36960368)

Why build a huge single reservoir when you can have a lot of smaller distributed reservoirs?

In an emergency situation where I have the choice between lights, or no lights, I will be dragging cables to may car. Whether or not it's electric is immaterial.

- Dan.

Re:Inefficient (3, Insightful)

Arlet (29997) | more than 2 years ago | (#36959862)

Obviously, as soon as day/night usage are the same, the difference in price disappears, and people will stop additional night time charging.

At the end, you'll get a much more stable power consumption which allows much more efficient power generation.

Re:Inefficient (2)

Lumpy (12016) | more than 2 years ago | (#36960026)

90% of homes do NOT have variable rate power. so you dont pay less at night. the losses involved with this setup are enough to offset any savings even if you had a variable rate billing based on time of day.

It's a net loss no matter how you look at it.

Re:Inefficient (1)

jo_ham (604554) | more than 2 years ago | (#36960162)

90% of homes in which country?

I'm not sure where you live, but my night time electricity is *considerably* cheaper than my day rate.

Re:Inefficient (1)

mcavic (2007672) | more than 2 years ago | (#36960352)

I'm not sure where you live, but my night time electricity is *considerably* cheaper than my day rate.

I'm in the middle of the US, and last I checked most homes still have analog power meters that count the total usage for the month. Also, my bill shows total usage without differentiating between day and night.

Re:Inefficient (1)

Arlet (29997) | more than 2 years ago | (#36960238)

Depends on where you live. Where I live, 90% of homes have variable rate power.

Also, the difference in power generation efficiencies is quite big. Base load plants can run at 60% efficiency, while peak plants run at 30%. If enough people power their own house during the day, and charge during the night, you can leave the peak plants off-line. The charge/discharge efficiency of the battery is about 90%, combined with 60% efficient power generation results in 55% which is much better than 30%.

Re:Inefficient (0)

kevinNCSU (1531307) | more than 2 years ago | (#36959524)

If backup generators were super efficient you'd be using them instead of paying for grid electricity. Efficiency isn't the point, keeping your food from spoiling during a power outage is.

Re:Inefficient (0)

bluefoxlucid (723572) | more than 2 years ago | (#36959544)

Yes but why does it take as much energy as it takes to run your house for 2 days just to drive your all-electric car a few miles?

Re:Inefficient (1)

CraftyJack (1031736) | more than 2 years ago | (#36959658)

Maybe that whole 1/2mv^2 thing? One horsepower is about 750 watts. So even an 80hp car is cranking out 60,000 watts. That's a lot of lightbulbs.

Re:Inefficient (1)

Culture20 (968837) | more than 2 years ago | (#36959700)

Because moving a big hunk of steel from A to B is harder than moving some heat from inside your fridge to the outside of the fridge. Just compare the size of gas tanks on a car versus a gasoline powered generator. That said, in an emergency scenario, I'd rather eat the food right away and save the energy for mobility to get to somewhere that has electricity.

Re:Inefficient (1)

CaymanIslandCarpedie (868408) | more than 2 years ago | (#36959836)

I live in the Cayman Islands so this could be useful here. When a huricane hits, there are no options to drive somewhere that has electricity.

Re:Inefficient (2)

Lumpy (12016) | more than 2 years ago | (#36960068)

OR get a fridge that is actually efficient to begin with. front door fridges are a very dumb design.

http://www.builditsolar.com/Projects/Conservation/chest_fridge.pdf [builditsolar.com]

From over 6 years ago.... this setup would keep food cold for several days without power. and at 100 watts used per day (4.2WattHour) a very small computer UPS will keep it running for most of the outage.

Re:Inefficient (1)

smooth wombat (796938) | more than 2 years ago | (#36960262)

That's fine except for one big issue: size. To get the same amount of space in a chest refrigerator as a conventional one would mean either you make it deep or long.

If it's deep, you run into issues with people not being able to reach to the bottom without leaning in, like one does with a current chest freezer, or you have to make it long to accommodate the same internal space.

Either way, this type of device would require nearly everyone to redo their kitchen to accommodate this new device as it will not fit in the space currently used by normal fridges.

I'm not saying this isn't a good idea, I'm merely pointing out why people would be resistant to using this type of fridge.

Also, what about the freezer portion? Nearly every fridge made has a separate freezer section. Adding that into the equation would, again, increase the overall size.

Re:Inefficient (2)

Lumpy (12016) | more than 2 years ago | (#36960332)

"Also, what about the freezer portion? Nearly every fridge made has a separate freezer section. Adding that into the equation would, again, increase the overall size."

do what rich people already do.

1 fridge
1 freezer
And the size stays the same... just laying down, look at photos of chest freezers. and there are already homes that use these types of systems already. the only problem is that people use the top of the fridge as counterspace.

Honestly who cares about pushing wide adoption. if you really care about efficency or trying to be off grid you make sacrifices for traditional looks or operation for what you are interested in. It's why most people that care about efficiency will not live in the typical poorly designed home.

Re:Inefficient (1)

Fishead (658061) | more than 2 years ago | (#36960172)

Ha ha ha... that reminds me of this time... oh... 10 years ago. There was this guy at work that had just bought a 2kg block of cheese from Costco, and the power went out. He was so worried about his cheese spoiling that he sat down and ate the whole block of cheese. Couple hours later, the power came back on.

      We did have an extended power outage due to a forest fire once where people were evacuated for 2 weeks. When they returned, they were told to move their fridges/freezers to the end of their driveways without opening them due to health concerns. Friends that were affected lost a lot of garden produce. The appliances were replaced by insurance/government assistance. Having an electric car tied to your home would have helped because I doubt it would have had the range to evacuate from the fire. As it was some of the towns along the evacuation route had to pack in generators to power the fuel pumps to pump fuel for people to evacuate.

      I'm fortunate enough to live in a province with a government run power monopoly who's mandate is to provide stable power instead of cheap power. We rarely have power outages and pay $0.667/kWh to $0.962/kWh for power (depending on consumption) that's almost entirely generated by hydro. I guess hydro-electric dams must be able to quickly scale for demand because we do not have day/night rates.

Re:Inefficient (1)

Fishead (658061) | more than 2 years ago | (#36960190)

Mistake due to insufficient coffee consumption...

My rates are $0.0667/kWh to $0.0962/kWh.

Re:Inefficient (2)

Junta (36770) | more than 2 years ago | (#36959768)

Because:
-Your day-to-day house energy usage doesn't involve accelerating a ton of mass to 60-70 mph repeatedly
-As a corollary, your house is not having to constantly spend energy to fight air resistance to maintain a high velocity
-Your car is poorly insulated with very large windows meaning the reduced volume of air to climate control is offset by the inefficiencies of dealing with thermal and light energy outside the car (even on pretty hot days, your house A/C generally gets to cut off a lot, in a car, that compressor generally has to run constantly on moderately hot days to maintain the same comfort).

Though 24kWh lasting two days still seems *very* optimistic. lights and refrigerator only would be my guess, and you probably would want to leave that fridge closed as much as possible. A/C might be ok so lang as not overly aggressive (might get 5-8 hours of runtime to spread out across the two days).

Re:Inefficient (1)

TheRaven64 (641858) | more than 2 years ago | (#36959966)

Though 24kWh lasting two days still seems *very* optimistic

According to my last electricity bill, I used 924kWh over six months, or around 5 per day. To use 24kWh in two days, you'd need more than double my electricity consumption. Given that I work from home (so have computers on and music playing most of the day), watch films on a projector (300W bulb), use a tumble dryer for all of my clothes and a dishwasher for all of my washing up, that seems insanely high.

Re:Inefficient (1)

robot256 (1635039) | more than 2 years ago | (#36960322)

And according to my TED power meter, 12kWh is close to the MINIMUM my house has ever used in one day. Usually it's 30-40kWh in fair weather and 60-80kWh in summer with AC running. It's an old house with poor insulation, five active people using indoor lights all day, two fridges, and lots of cooking on the electric range and laundry in the electric dryer. We also do crazy things like paint the house in the summer which requires the AC be running with the windows open. Granted, if the power went out and we were running only the fridge and lighting it would go down considerably. But it will be much more practical to install ~3kW solar panel array than to rely on an electric car battery.

On the other hand, your household seems like a perfect candidate for this technology. Could be a lifesaver, especially if it means you could keep your business running during an outage.

Re:Inefficient (1)

afidel (530433) | more than 2 years ago | (#36960482)

924kWh *total* or per month? Because I could absolutely believe 924kWh per month, it puts you just above the US average of 908kWh/month but over six months I find that VERY hard to believe as that's 1/6th the normal which would be like some of the very extreme solar powered off grid houses I've seen using DC appliances.

Re:Inefficient (1)

vlm (69642) | more than 2 years ago | (#36960072)

Yes but why does it take as much energy as it takes to run your house for 2 days just to drive your all-electric car a few miles?

The other answers are getting bogged down in wordiness and too many numbers.

Here's a simpler way to look at it, just look at the ratios of power output vs time duration.

The motor in your car is about ten to a hundred times bigger than the sum of the working electric motors in your house, right? Very roughly?

Given that, a chunk of energy runs your house about ten to a hundred times longer than it runs your car, right? Very roughly?

Makes sense to me...

Re:Inefficient (1)

Bob the Super Hamste (1152367) | more than 2 years ago | (#36959690)

A decent backup generator fairly efficient (still not as good as a combined cycle gas turbine) the cost factor is actually the fuel costs. If you really wanted you could go get a big stationary 2 stroke diesel similar to what they put in cargo ships or in 400 ton trucks which are close to 50% efficient. Backup generators that use natural gas are cheaper than diesel ones but coal power for the grid is still lower cost. Also costs increase because the fuel isn't purchased on an industrial scale.

Re:Inefficient (1)

GameboyRMH (1153867) | more than 2 years ago | (#36959826)

In many countries where electricity is expensive, even small factories buy and maintain their own diesel generators to save money.

Re:Inefficient (4, Insightful)

cyberchondriac (456626) | more than 2 years ago | (#36959560)

I don't think efficiency is their primary goal here. It's chief purpose is to temporarily power a house during an outage. I suppose you could use it regularly but that seems kinda odd.
I'm curious about this though: from TFA: "..is sufficient to power an average Japanese home for about two days" - I wonder how that translates to the "average" US home (assuming there is such a thing).

Re:Inefficient (2)

mr1911 (1942298) | more than 2 years ago | (#36959824)

I'm curious about this though: from TFA: "..is sufficient to power an average Japanese home for about two days" - I wonder how that translates to the "average" US home (assuming there is such a thing)

about 15 minutes.

More if a few of the 55" plasma TVs are shut off.

Even more if homeowners realize that, with proper landscaping and insulation, it is possible maintain a very comfortable temperature with the windows open and air conditioner off even when it is 90 degrees outside.

Re:Inefficient (1)

Arlet (29997) | more than 2 years ago | (#36960000)

Even more if homeowners realize that, with proper landscaping and insulation, it is possible maintain a very comfortable temperature with the windows open and air conditioner off even when it is 90 degrees outside.

Actually, with proper insulation, you'd want the windows closed, otherwise all the hot outside air just blows in. I don't have AC in my house, and during hot summers it's quite a bit cooler inside than outside, provided I keep all windows closed.

Re:Inefficient (1)

Lumpy (12016) | more than 2 years ago | (#36960144)

"Even more if homeowners realize that, with proper landscaping and insulation, it is possible maintain a very comfortable temperature with the windows open and air conditioner off even when it is 90 degrees outside."

I had a home that we almost never ran the AC during the summer because it was properly built and engineered. IT was a Geodesic Dome home that had a row of windows at ground level on the windward side and a cupola at the peak of the dome with windows that would open. Even on 98 degree days it was 10 degrees cooler in the home. and that temperature differential coupled with moving air made it very comfortable even in 60% humidity.

The problem is most homes are designed by morons for a "look" and not for efficiency or even occupancy.

Re:Inefficient (1)

Infiniti2000 (1720222) | more than 2 years ago | (#36960410)

Even more if homeowners realize that, with proper landscaping and insulation, it is possible maintain a very comfortable temperature with the windows open and air conditioner off even when it is 90 degrees outside.

Nope, impossible here in Florida. The high temperatures coupled with the high humidity make not running the air conditioner not an option. Anyone who says otherwise is a fucking moron. You can get away with murder here in Central Florida, but not without an air conditioner.

Re:Inefficient (1)

gr8_phk (621180) | more than 2 years ago | (#36959626)

This looks stupidly inefficient. Either the car takes too god damn much energy to run; it has too huge of a battery; or it can't power a whole house for long.

Dude, it's an electric car. It probably has close to 20KWh of storage. That means 20 killowatts for an hour or 1kW for 20 hours - you get the picture. The problem is that the leaf is a pure electric vehicle. Doing this with a Chevy Volt would be better since it could run on gas like a regular generator. There is some additional cost to make the charging system bidirectional, and there are certainly additional requirements on any system that can push power onto the grid. But yes, this is a neat trick that's not too hard to do once you've got a high power charger on an electric or hybrid car.

Re:Inefficient (1)

Maury Markowitz (452832) | more than 2 years ago | (#36960100)

"vehicle to supply electricity to power a house during a power outage or shortage"

How often do those happen where you live? In Toronto, it's about once every decade, or less.

Given that this occurs less often than I would replace the car, the effect on lifetime would be effectively zero.

So then I would be perfectly happy to draw on my batteries when there's a blackout.

Been done already (1)

NixieBunny (859050) | more than 2 years ago | (#36959518)

This [hiwaay.net] guy did it years ago with his Prius. Trouble is, his electric utility is so reliable that he never gets to use the feature!

Re:Been done already (1)

vlm (69642) | more than 2 years ago | (#36960188)

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 google, seems like QST magazine october 2005 is likely, but...

Re:Been done already (1)

fractoid (1076465) | more than 2 years ago | (#36960446)

Also, these guys [acpropulsion.com] 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 so new (0)

Anonymous Coward | more than 2 years ago | (#36959526)

This has been proposed before. It could become an essential ingredient in the overall energy strategy, buffering energy from erratic but renewable sources like wind and solar.

not that simple (3, Interesting)

meridien (718383) | more than 2 years ago | (#36959538)

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.

Re:not that simple (1)

Anonymous Coward | more than 2 years ago | (#36959664)

Glad you pointed that out. Originally we were going to make it so easy a monkey could do it, but we didn't realize there were such things as electrical codes.

Cordially,
-Nissan

Re:not that simple (1)

Bob the Super Hamste (1152367) | more than 2 years ago | (#36959864)

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 people aren't like my father and don't need to run big hydraulic presses, lifts, compressors, or welders

Re:not that simple (0)

Anonymous Coward | more than 2 years ago | (#36959878)

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

I am from the Netherlands, you insensitive clod. 220V IS our regular wall voltage over here (well, 230V I suppose).

Re:not that simple (1)

Bob the Super Hamste (1152367) | more than 2 years ago | (#36959962)

Yes I know that most of the rest of the world runs 220V (well 210V to about 250V), but the largest readership of /. is American so think of it more as a FYI for them.

Re:not that simple (1)

mr1911 (1942298) | more than 2 years ago | (#36959894)

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?

Re:not that simple (0)

Anonymous Coward | more than 2 years ago | (#36959974)

The lineman first checks the line -- not hot. He starts working on it. Then you connect your generator to the line that he has previously determined to be cold. He's smart and careful. You're dumb and careless. But he's the one who doesn't go home.

Re:not that simple (1)

Arlet (29997) | more than 2 years ago | (#36960110)

The lineman first checks the line -- not hot. He shorts the line. He starts working on it. He gets to go home at night.

Re:not that simple (0)

Anonymous Coward | more than 2 years ago | (#36960234)

Obviously you know nothing at all.

Linemen treat a wire as live all the time. Plus I don't see many of them making sure they are grounded and standing in a puddle while they touch a wire. they ALWAYS are insulated from ground. Plus many of them work on live wires. Most of the time you cant kill the power.

Next time find out how they actually do their job instead of just making things up.

Re:not that simple (1)

Rashdot (845549) | more than 2 years ago | (#36960168)

Never just grab a power line, use the back of your hand to check it first. If there's still power on it your hand would close and you wouldn't be able to let it go if you touched it with the front of your fingers...

Re:not that simple (0)

Anonymous Coward | more than 2 years ago | (#36959952)

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.

Oh, great... the "first post" of every article that even hints at grid inter-tie. Ok. We get it. We've gotten it for the last 40 years. You can't just plug a generator, inverter, etc. into your house wiring with a spliced extension cord or even a more professional-looking variant thereof. Transformers work in both directions. Duh. I strongly suspect that Nissan has considered this. Why has this warning, always phrased as if the audience has never considered it, become so fashionable lately?

Re:not that simple (1)

vlm (69642) | more than 2 years ago | (#36960384)

Its an urban legend, its not even true. Unless your hybrid vehicle is a multi-megawatt nuclear submarine, backfeeding an entire neighborhood will instantly kill any normal sized generator.

Now there are interesting ways to kill someone using a generator, but they don't involve backfeeding a neighborhood. The drop fuse goes off like a grenade, unfortunately while the lineman is holding it. The lineman walked thru a rain puddle energized by an extension cord laying in the puddle, coincidentally for the purpose of backfeeding. Any accident even remotely involving a generator and a lineman is always reported via the journalist filter as being due to "backfeeding" even if the actual accident report is the lineman tripped over it laying on the ground, or a refueling fire incident.

Re:not that simple (1)

Rich0 (548339) | more than 2 years ago | (#36959976)

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 somewhere being closed was going to be astronomically low, but assuming that safeguards fail is part of being anal-retentive about safety.

Re:not that simple (1)

Bengie (1121981) | more than 2 years ago | (#36960084)

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.

Re:not that simple (1)

vlm (69642) | more than 2 years ago | (#36960320)

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 thru the oilpan type of destruction.

Humorously the only people who retell this story are those who never tried it. Anyone who has actually tried this, knows for a fact that its a miracle if you can backfeed merely your own house without blowing the generator.. the inrush current of the fridge, freezer, AC compressor, furnace blower, dehumidifier, computers, maybe an oven, clothes dryer, or dishwasher that was on when the power cut, and sump pump all trying to instantly start will blow the breaker for sure... now scale that up by an entire subdivision, say a hundred homes, sometimes I wonder its a miracle the grid can be brought up at all without blowing itself back down. The inrush current to an entire subdivision must closely resemble the lightning strike that took it down...

Doesn't suprise me (2)

Bob the Super Hamste (1152367) | more than 2 years ago | (#36959592)

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.

Convenience (1)

SEWilco (27983) | more than 2 years ago | (#36959608)

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 getting, I'd just want to avoid having to eat everything in the freezer within two days. As tempting as that sometimes might sound.

soaks up excess grid capacity (3, Interesting)

bre_dnd (686663) | more than 2 years ago | (#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.

Re:soaks up excess grid capacity (0)

Anonymous Coward | more than 2 years ago | (#36959912)

What about capital costs of setup of this system?

Taking power out of a grid is easy. You just plug in then charge when rates are low (ie. the rage behind "Smart Grid"). But this ain't easy to do to power your house from the battery. There are considerations,

1. Converter is needed to power grid
2. Safety needs to be a considerations - you can only supply power if grid is energized or you can kill people working on a downed line, etc.
3. Batteries wear out - that's why they are almost never used for grid backup power - VERY expensive and VERY limited.

So yes, great idea until you think about it. It will not save you money by a long shot, in battery costs alone, never mind the rest of the capital costs!

As to energy generation and demand, the demand is predictable and there is appropriate measures taken to minimize the costs (eg. fuel, wear and tear, etc). Electricity at night is not cheaper because there is excess capacity running into ground. It is cheaper because there is cheaper always-on capacity running providing a larger percentage of the total mix as more expensive power is off.

Pumped storage is arbitrage between expensive gas turbines (especially when gas prices go up) and cheap coal/nuclear. It is a highly efficient, 100% reusable battery system that cannot ever be matched by an electrochemical battery - gravity doesn't wear out! :)

Re:soaks up excess grid capacity (2)

kiwimate (458274) | more than 2 years ago | (#36960334)

One of the big problems with "smart grid" as a term is it's so nebulous. There are plenty of people who are really, really clever and very, very experienced who will argue passionately that we already have a smart grid and we should be more properly talking about a smarter grid. But there are as many definitions of smart grid as there are consultants looking to make a buck.

Look at this definition [nerc.com] :

smart grid - The integration and application of real-time monitoring, advanced sensing, communications, analytics, and control, enabling the dynamic flow of both energy and information to accommodate existing and new forms of supply, delivery, and use in a secure, reliable, and efficient electric power system, from generation source to end-user.

Frankly, I don't like this definition because it's way too verbose. If you want to get to the essence, it's two way communication and control.

But here's the thing to keep in mind. Lots of people have cars. Not a lot of people have a pumped storage facility, or even the geography to set one up.

Energy demand is indeed highly predictable, but there's always an element of the unknown. The issue we're finding these days is energy generation can be highly predictable but public sentiment wants it to be clean and green without realizing that you sacrifice the reliability and/or the price efficiency of coal. Everything in electricity is about arbitrage, at least at the wholesale level.

Forget about saving money. If you already have a car, which in modern day U.S. many people see as a necessity (please, no-one respond with your anecdotal "not me, I take the bus/ride my bicycle everywhere" - that's not my point), and are now told you can effectively use it as a giant whole-house UPS, that's going to be worth something to a lot of people.

Re:soaks up excess grid capacity (0)

Anonymous Coward | more than 2 years ago | (#36960210)

yeah... sounds great, including the decreased battery life from such activity, wich will then be even better for them to sell another battery for 7k or so $/€ every 3 years or less. Not economical at all imo.

Re:soaks up excess grid capacity (0)

Anonymous Coward | more than 2 years ago | (#36960366)

"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."

I'd never even thought about this in depth before, but the simplicity of the above is full of win!

Penny drops (4, Interesting)

arkhan_jg (618674) | more than 2 years ago | (#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.

Not exactly a new idea... (0)

Anonymous Coward | more than 2 years ago | (#36959654)

Been doing this for years with an inverter, a regular gasoline vehicle, and a dropcord. Start car, connect inverter to battery, connect dropcord to inverter, run dropcord to location that needs electricity, plug in electrical device, eat cake. Yes, it turns your vehicle into a very inefficient generator. But when the power's out and you need to run a radio or TV to see if the tornado is heading your way, then maybe kw/gal doesn't really seem that important.

Great! We can eliminate peak load (0)

Anonymous Coward | more than 2 years ago | (#36959694)

by having everyone charge everything at night!

I remember when this was a fuel-cell discussion... (1)

dAzED1 (33635) | more than 2 years ago | (#36959770)

There was a time when people discussed the idea of having natural gas be the fuel for a small fuel cell system in homes, with the hydrolyzer being there at the house. Then, when you got home with your fuel cell car, you plugged in, fueled up, and then the fuel cell plant in your car would add to the power generation capability in the house. The idea was that when you're not home, you don't need as much power at your house. I was hoping that future would eventually happen, now we're just talking about batteries. Much less...sci-fi, cool, etc. Charge a battery so the battery can power a house later? Why not just...have battery powered LED lights for the short term emergencies (since that's all your car would cover well, anyway) instead of the extreme waste from the energy you'd bleed off during conversion and transmission?

Re:I remember when this was a fuel-cell discussion (0)

Anonymous Coward | more than 2 years ago | (#36959838)

Sorry for posting AC.

I'm also worried about the extra charge/discharge cycles shortening the life of the car's battery. This is one instance where Top Gear actually has it right. Batteries are not the way forward for electric vehicles.

Re:I remember when this was a fuel-cell discussion (1)

vlm (69642) | more than 2 years ago | (#36960500)

Why not just...have battery powered LED lights for the short term emergencies (since that's all your car would cover well, anyway)

Uh, not quite.

My wife's prius generates about 60 horsepower.

conservative 60 hp * conservative 700 watts per hp / conservative 220 volts = sometime like 190 amps. Probably, with the help of the batteries, a short term surge of 400 amps would be possible.

Its an older house; I believe we only have 100 amp service. Technically I could run both my house and my neighbor's house across the driveway 100% full blast. In practice I don't think either of us own 100 amps of load; but then again running a car flat out full power for long periods of time is a bad idea.

Anyway in summary its quite realistic to run an entire house off a Prius. Not just some lights and the fridge....

Even my old saturn alternator supposedly is capable of a kilowatt of continuous sustained output, according to the high power ham radio guys. Thats... a lot of power.

Really really useful here! (in Vietnam) (2)

wisebabo (638845) | more than 2 years ago | (#36959786)

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.

Re:Really really useful here! (in Vietnam) (1)

Dcnjoe60 (682885) | more than 2 years ago | (#36959936)

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 battery can only provide power upto the power that was put into it (actually a lot less as it is not 100% efficient). Therefore, to charge your Leaf takes power from the grid. Using the Leaf to power your house just replaces the lost power from the grid (plus it means you won't be able to drive anywhere because the battery is depleted).

A much better solution, if you are in areas prone to power loss, is to have a backup generator. If you aren't in such areas, then a little portable generator to power your refrigerator, if you are really concerned about it, would be a lot cheaper. Of course, you would have to balance the cost of replacing the spoiled food against the cost of the generator. For most people, it would be cheaper to replace the food if long lasting power outages are a rarity.

Oops! Thought the Leaf was a hybrid! (1)

wisebabo (638845) | more than 2 years ago | (#36960118)

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.

What about the car? (0)

Anonymous Coward | more than 2 years ago | (#36959880)

A couple years ago here in the U.S., a bad wind storm came through and knocked out all power in our city. It took several days for them to bring the grid back up for everyone again, but in the meantime, EVERYONE was without power. Including the gas stations. Unfortunately, I still had to get to work every day, and it got to the point that people could not do anything for lack of gasoline to get anywhere.

So, supposing this happens again, and I own an electric car, this is a great strategy for keeping the house up and running. But now my car is depleted. How do I get to work or go anywhere? Even if there was an electric re-charging station (and there's not), then there's a good chance they will out of power as well.

Something tells me this was not thought through too well.

did it for 'canes (1)

i.r.id10t (595143) | more than 2 years ago | (#36959888)

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 and at night. Day time I came in to work, wife and kids went to the mall.

Re:did it for 'canes (0)

Anonymous Coward | more than 2 years ago | (#36960046)

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 and at night. Day time I came in to work, wife and kids went to the mall.

I've got a 2500W inverter that I hook up to my 4Runner to run our fridge when the power goes out. Cut the breaker for the fridge, disconnect the cord at the top (it's a built-in and easy to access the power connection) pop on the extension cord I made with lugs and pop on the inverter and away it goes. Doesn't draw much power unless the defroster kicks in.

Great idea! (0)

Anonymous Coward | more than 2 years ago | (#36959900)

then when I dont show up for work, I can use a power outage for being out all day.
first my alarm clock reset because of the power outage and I didn't get woke up on time, then my electric car was dead because it didn't get charged overnight and it was supplying power to my house.

Outdoor night film shoots (1)

Woogiemonger (628172) | more than 2 years ago | (#36960006)

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 a car like the Nissan Leaf... this is just an added benefit.

Re:Outdoor night film shoots (1)

vlm (69642) | more than 2 years ago | (#36960542)

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.

A few potential drawbacks (1)

grimmjeeper (2301232) | more than 2 years ago | (#36960044)

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 for the car is inside a garage. Having a gas powered car run in the garage is a "bad" thing last time I checked. Though a well designed ventilation system could help.
  4. Cost of operation. Having your gas powered car generate your electricity is a horribly inefficient method. Dedicated generators are much more efficient. If you live in an area with natural gas, you can hook up your auxiliary generator to the natural gas supply and get your backup power much more efficiently.
  5. Capacity. The charging/generating circuit won't be able to power the whole house. Sure, you could keep the fridge going to keep your leftovers from spoiling. But you probably can't run the whole house. A dedicated generator can supply more than enough power to run the whole house and still cost less to run.
  6. 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?
  7. I'm not going to buy an overpriced car just to serve as my backup generator.

I'm sure that some people may have a use for this technology. But it's a niche market at best.

Re:A few potential drawbacks (1)

Arlet (29997) | more than 2 years ago | (#36960442)

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.

Re:A few potential drawbacks (1)

Arlet (29997) | more than 2 years ago | (#36960540)

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

Why do you even need the car?... (1)

twistedsymphony (956982) | more than 2 years ago | (#36960094)

... 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?

Re:Why do you even need the car?... (1)

scorp1us (235526) | more than 2 years ago | (#36960202)

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.

Re:Why do you even need the car?... (1)

Arlet (29997) | more than 2 years ago | (#36960326)

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.

Re:Why do you even need the car?... (1)

ickleberry (864871) | more than 2 years ago | (#36960260)

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 wave inverter into an ordinary car or old car battery and you can draw some power from it, enough to dry your hair anyway and still have enough left to start the car

but! (0)

Anonymous Coward | more than 2 years ago | (#36960154)

What problem are we really trying to solve here! the car or the house?

What about backfeeding the grid? (0)

Anonymous Coward | more than 2 years ago | (#36960158)

Did they think anything about the fact that they are back feeding the grid? If you put power in the outlet that you are SUPPOSED to be getting power OUT of you will in effect be back feeding the entire grid unless you shut off the main breaker until power is restored. The power companies kind of frown on that and that is why NEC says you have to use a transfer switch so you can only get power from one source at a time. Thinking about this further isn't this built INTO a car so it won't do this? There must be......mustn't there?

Re:What about backfeeding the grid? (1)

ledow (319597) | more than 2 years ago | (#36960298)

Because those people who have solar, generator backup, etc. are all blowing the grid 24 hours a day, aren't they?

You install a breaker (mandated by law in some places, for exactly this reason). That breaker cuts off the grid supply and powers the house from the car instead. Power comes back up, you switch it back over. You could probably even design a "smart" breaker that will do just that for you automatically.

At no point has anyone ever suggested that you pump power back to the grid (but that, also, is feasible - see how solar panels feed back to the grid), or join the two at the same time (because even if it's same voltage, it most certainly won't be the same AC phase and will blow the crap out of the street transformer's fuses).

Free energy! (0)

Anonymous Coward | more than 2 years ago | (#36960222)

Use your car to power your house, then charge your electric car from your house. Voila: free energy.

Use an EV car as backup energy source (1)

rossdee (243626) | more than 2 years ago | (#36960270)

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.

Dangerous if done wrong (2)

cavehobbit (652751) | more than 2 years ago | (#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.

What about my diesel BMW (0)

Anonymous Coward | more than 2 years ago | (#36960520)

Any way to turn my diesel x5 into a florida hurricane disaster energy center for a few hours each day??

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