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Use Your Car To Power Your House
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."
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.
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).
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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
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.
Time to offend someone
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.
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.
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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).
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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.
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.
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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.
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.
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Or do what most electrical companies do, build a power reservoir.
http://en.wikipedia.org/wiki/Ludington_Pumped_Storage_Power_Plant
Problem is a LOT of power is lost in the process, Just like using the car battery or even a dedicated battery would.
Do not look at laser with remaining good eye.
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
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.
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"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.
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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.
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.
That's the thing... how much more are you spending to buy that electric car, and how does that compare against buying a $1000 electric generator to power your appliances? That's about what I spent on my current genny, which produces 7.5kW (got it on sale, regular price was $1400), and that's plenty for the sump pump, the freezer, the fridge, and the percolator. Our neighbours run their sump pump off our genny too, actually.
It's a really good idea if you're buying an electric car anyway, but buying an electric car specifically for this is horribly inefficient, and wasteful. If the battery really has enough juice to power the average home for 2 days, then as the OP said, either the car has a battery that's *way* larger than it needs to be, or the car is using *way* more electricity than it needs to. Or they're *way* underestimating how much power the average house uses... TFA says the battery is 28KWh... that's the equivalent of running my generator for 4 hours. Now, my generator produces about twice as much power as we actually need during a power failure (which is why we let the neighbours piggy back their sump pump off it), but if we were running the TV, the computers, the laundry, the air conditioner? There's absolutely no way that a 28KWh battery would provide enough juice to run the place for 2 days. 1 day, if we stretch it, but probably closer to 8 hours of normal daytime household load.
The key thing is that this setup is actually very good for emergencies, specially in densely populated areas like urban Japan where you can't put easily a household generator like in small apartments.
From TFA:
The lithium ion batteries in a Leaf can story up to 24kWh (kilowatt hours) of electricity, which Nissan estimates is sufficient to power an average Japanese home for about two days. That means if the system was used for a few hours during the day, the car would still retain enough power to make trips.
Since supply is very tight in central and eastern Japan and they are forecasting that these zones will be facing power shortages up to the year 2014, this system is a very good fit to smooth the power demand. For example, for Tokyo Electric Company service area, the demand curve is in this link:
http://www.tepco.co.jp/en/forecast/html/index-e.html#graph1
The yellow band is the time that TEPCO is requesting customers to reduce their demand to prevent blackouts. If this system becomes widely used instead of seeing their demand drop below 49% at 3 am. and getting close to 100% at 8 pm. in normal circumstances with the help of customers they could increase the demand in the midnight hours and decrease their peak demand even if customers go with their normal energy consumption, and in the process achieve something similar to a smart grid without actually building it.
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Personally, I just leave them in there. It's like having having a personal food assistant, because they know where everything is. Just last night he handed me some frozen steaks from the bottom of the chest that I forgot I even had.
Srsly u guys. U guys, srsly.
Hint: it doesn't have to be YOUR HOUSE that you're supporting. How many cars are in areas of Japan that were unaffected by the tsunami? How many of those owners would have charged up, driven a little closer to the region, and donated the remainder of their charge to help their neighbors? The elders in Japan once scoffed at the current generation of Japanese youth as lazy and disconnected with society-- until they came by the thousands to offer their sweat and tears for the Fukushima region.
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He confused his dollars and cents. In the middle of the U.S. where I live I pay $0.11544 per kWh from June through August. (That's 11.544 cents.) So yes, you still pay three times what we do. But not 450 times more.
My electric co-op also offers a controlled interruptible service plan. For all my heat pump electricity, instead of $0.11544/kWh I pay only $0.0480/kWh year round, but it's hooked to a controller that can interrupt electricity to it during peak seasons or during emergencies. During peak usage periods, they send out a radio signal to everyone's interrupters. Each interrupter shuts off its load for 20 minutes out of each hour. Spread across the thousands of subscribers, they are able to reduce their peak demand during the hottest days of the year. Reducing peak demand means they were able to delay purchasing additional generating capacity, saving the co-op millions of dollars. The "inconvenience" to me is that my house gets a little bit warmer for a few hours on the hottest days. According to my wife, the rise in temperature is indicating the end of the civilized world, but I barely even notice, and for that I think I save about $40 a month on the electric bill in the summer.
John