Nissan's LEAF-to-Home System Could Power a House for Two Days

By · December 22, 2011

Nissan LEAF-to-home

Nissan says its LEAF-to-home system could power a typical house for two full days.

In a recent demonstration at the 2011 Tokyo Motor Show, Nissan showed how the LEAF electric car could power an entire home by being connected to a power control system that's hooked up to the home's electrical system.

The automaker's so-called Smart Home Charging technology is designed to encourage consumers to use a Nissan LEAF to reduce load on the electric grid during peak hours. The idea is simple: Basically, owners charge up their LEAF during low load times and then use the LEAF's 24-kWh battery pack to power their homes during peak hours. For example, LEAF owners charge their vehicle overnight and then utilize some of that stored energy to power their home—essentially powering items like a toaster in the morning or their television in the evening from their car's battery pack.

In the demonstration, the LEAF powered Nissan's specially-designed Smart House, but the automaker is confident that the technology could be used with existing homes. Nissan says that in March 2012 the power control system box will go on sale in Japan at a price of approximately $6,200. According to Nissan, the LEAF's 24-kWh battery pack could power a typical Japanese home for two full days.

Nissan says that in order for the system to work properly, homes must be equipped with smart meters, a requirement that could limit growth of the technology. Nonetheless, Nissan believes that its LEAF-to-home system will gain popularity within the next five years. That forecast coincides with the vehicle-to-grid forecast from Pike Research—a US-based clean tech analyst firm—which says that globally by 2017, approximately 90,000 light-duty vehicles and an additional 1,500 medium/heavy duty trucks will be enabled with V2G technologies.


· · 6 years ago

Won't UPS companies be thrilled to hear this. This will be especially valuable in third world countries where the power goes off multiple times a day. Not sure how they'll pay for the car exactly, but some day.

· · 6 years ago

I want one (but not for $6K).
But I'm not really seeing how it will be of much use at homes except, possibly for stay-at home people since most Leafs, I assume, are driven to work during the day and charged at home at night so they aren't connected to the grid during the peak loading times. Maybe if these were connected to workplace chargers, they would have more impact.

· · 6 years ago

I agree that $6k does seem a bit expensive, but I'm sure the price will come down over time.

It would be awesome if you could use an otherwise grid tied solar system to directly charge the Leaf's battery when the grid is down. It would give you huge flexibility in the event of a natural disaster.

· · 6 years ago

I'd like to see some level of 120VAC output available on the vehicle, so you could have portable AC power. I've been thinking of adding one to my conversion, about $450, mass market would make it cheaper.

· · 6 years ago

There's no way I would consider using finite battery cycles on my LEAF battery to power my house. If you are hell bent on doing this then buy a stack of cheap lead acid batteries don't use your LEAF.

· · 6 years ago

It depends on how you use it. Powering the entire home for a few days should only be in an emergency. Shallow cycling a small amount to support the grid for short periods of peak load should not affect the cycle life at all.

· Chris T. (not verified) · 6 years ago

Note that the average Japanese house (whatever that means—is it like the average human being, with one breast and one testicle, or is it really a valid average?) uses just 10 to 12 kWh/day, which comes to roughly 300 to 360 kWh/mo. A "low usage" American home tends to be twice that or more. Californians tend to have the most efficient houses, and even there 700 kWh is considered pretty frugal.

· · 6 years ago

Why would I want to take my $15k-$20k battery pack in my Leaf and take away life of the battery by using it for my house. I want my EV battery to last over 10 years and don't want to over use it, lowering the life and end of life range.

A better option is to use the old battery packs that are no longer energy effective in a car but are ok for home power/energy use and put it in my basement with this smart home charging system. This is already being done.

· · 6 years ago

Two things this made me think of posting:

1) IIRC, after the earthquake and tsunami, Toyota decided to offer (standard? as option?), on their Prius an outlet so that it can act as an emergency electricity generator. Not sure when that will come to America. Maybe 2014 model year. If anyone knows, please post.

2) white LED lightbulb replacements have gotten a LOT cheaper in just the past year. Home Depot has some (Philips AmbientLED). They're still many times more expensive than incandescents, but they last for ~15-25 yrs (thus justifying their expense for hard to replace locations), and are tons more efficient, so if you do need to run your house off of your LEAF batteries or Prius' engine, you can get light + more other electrical things compared to incandescents.

· · 6 years ago

@Chris T. - "Californians tend to have the most efficient houses"
Out of curiosity, I looked this up. It seems that the prize for the lowest consumption (which of course is not necessarily the most efficient) goes to Maine. Not what I would have expected! Of course CA is among the lowest, and we're almost as low in NY. Anyway, given these numbers, the LEAF wouldn't power the average US household for a day (920/month / 30 ~ 30 kWh/day).

· · 6 years ago

"Californians tend to have the most efficient houses"
This is dead wrong. California tends to have the most energy efficient climate. The houses in California are terrible with regards to energy efficiency. Many have no insulation at all and windows that leak like sieves.
It just shows that you can interpret data any way that suits you.

· · 6 years ago

This Nissan Leaf integration scenario with home power reminds me of the sort of thing that Sanyo touts with their rechargeable Eneloop AA and AAA low-self-discharge batteries. Both Nissan and Sanyo create a marvelous product and then provide no shortage of ways to implement them . . . some good and some, well . . . sorta goofy. I agree with all who note that Nissan's idea can't be very good for the long term life of the Leaf's battery pack and that it probably only works best for those who will leave their EV at home and plugged in during daylight hours.

But, yes, time to make the typical American house more efficient. Even if you aren't yet able to install a PV system, better windows and insulation goes a long way. I, too, have noticed that reliable and affordable LED lights are now commonplace in big box stores. I've had very good luck with this particular one . . .

· Chris T. (not verified) · 6 years ago

@ex-EV1 driver: Efficient climate certainly helps. :-) There's a huge gap between older and newer homes too though (throughout the country), which affects the numbers a lot.

@Brian Schwerdt: Interesting. However, one also has to consider the source of heating (and, in the case of most of Calif except the northern-half-coastline, cooling). I know a lot of Washington state houses have electric heat, because they had super-cheap ($.03/kWh and the like) hydroelectric rates (not anymore, of course...).

I know someone who lived in Vermont for a few years and had electric heat. At something like $.17/kWh. Ouch.

· · 6 years ago

Last winter I went two and a half weeks with no grid power. I certainly wished I had an EV that could power my home then, I could have driven to work, gotten a full charge, then run the basics at night. As it was I survived by doing essentially the same thing with some AGM batteries and a 12 volt inverter, I'd switch them out and take some to work and charge them up each day. That allowed me to keep the blower on my wood stove going 24 hours a day and have TV and internet access at night. I would have gladly traded a few cycles on my pack for a more convenient way to power my home, if indeed the minor cycling would have affected it at all.

· · 6 years ago

@Chris T. - "I know someone who lived in Vermont for a few years and had electric heat. At something like $.17/kWh. Ouch."
Yeah, this is why electric heat is very uncommon in the northeast. At first I was surprised to read about electric heat at all, and suggestions like insulation/windows. Obviously those are good for efficiency, but they won't save me much electricity (if any at all).

You make an excellent point. Many people I know have a generator for their homes. This is a much more marketable angle than load-leveling from the consumer's perspective.

· · 6 years ago

Of course load leveling could have a benefit as well. You might get a fee for allowing your pack to be available for load leveling, or some compensation if it were actually used for such. Most load leveling demands are for short periods of time, so providing 10-15 minutes of grid support will not tax the pack in any noticeable way but could be worth quite a lot to the power company if it helps keep the grid stable.

· · 6 years ago

I like the fact that the rice cooker takes more energy than the refrigerator, TV, computer and lamps combined.

· Doug Liser (not verified) · 6 years ago

I believe many areas in California have already banned V2G for safety reasons. Firefighters don't want to encounter high voltages in the house after they think they've disconnected the power.

California homes are among the most efficient, We have strict building rules and have tariffs that severely punish heavy users with overages up to $0.50/kwh. When I go to the East Coast it looks like something from the 19th century.

A lot of the state gets insanely hot in the summer and uses plenty of AC. That's why Maine uses least on average.

· · 6 years ago

That doesn't make sense, there are already many grid tied solar systems in place and they can deal with those. Probably another switch to isolate them, similar to transfer switches that isolate generators from the line.

· · 6 years ago

@Doug Liser, "California homes are among the most efficient, We have strict building rules and have tariffs that severely punish heavy users with overages up to $0.50/kwh."

Perhaps that is true for newly built houses, but it certainly isn't true for much of the California housing stock. My last California house had single pane windows, in crude aluminum frames with no thermal block, simple 2x4 walls, and not much insulation to speak of. There are millions of simple tract houses like that still in use today. Around here 2x6 walls and double pane windows have been the bare minimum since long before my last California house was built.

ex-EV1 driver was right: much of California has a mild climate that requires relatively little energy for heating and cooling. That's why so many people moved there over the last century.

· Anonymous (not verified) · 6 years ago

The best use is to use your solar power roof panels to charge the car during the day and then discharge the car at night to power your lights, TV, etc. That's what I plan to do with my SolarCity 800kwH of panels and Nissan Leaf. Well, just as soon as I get a smart panel from Xcel Energy and the 'Leaf to home' setup done. That will be cool no worries about blackouts, wars, etc. While the rest of the block is blacked out I will be busy watching TV with my lights on!

· · 6 years ago

Anonymous - this is a little off topic, but your comment reminds me of the Family Guy clip with Edison blasting speakers, all the lights on in the house, and the neighbor comes out holding a candle, to complain about the noise... :)

· More2bits (not verified) · 6 years ago

This is ideal for our solar power panel setup and Nissan Leaf. Which I don't care if the battery pack last 5 years or less which in 5 years they will be making battery replacements for a fraction of the cost of current batteries and with 10 times the range and 10 times the charging speed.

Read this and weep all you oil and gas users:

· More2bits (not verified) · 6 years ago

In about 5 years they will be making batteries for the Leaf that extends the range to 1000 miles or more.

Think I'm kidding?

Check this out:

· · 6 years ago

You might want to calm yourself a bit, those are older articles, and no way will we have 1000 miles range or more in 5 years. Not that we need 1000 miles of range, ever.

· NISSANMASTTECH (not verified) · 6 years ago

What a great option to able to run your refrigerator and heater during a power outage from your EV. Seems to me that someone will come up with an affordable (and safe) inverter.

· · 5 years ago

JRP3 I stand by the articles which are very current you are wrong.

And get this:

So in addition to the huge battery increases coming in the near future that you are so wrong about--you probably work in the Big Oil industry--we will have solar panels that are cheaper than using natural gas, coal, or oil to charge our batteries.

Here is another recent (January, 2013) battery evolution:

I think your going to be shocked what's coming down the pike. No less than 20 different new technologies are on the horizon which can increase density by more than 50 fold when combined and some of them can be (vary the substrate, the cathode, the anode, etc).

· · 4 years ago

It’s better to prefer these systems that come along with the brand rather than updating it without prior knowledge. Even though it can help in improving the sound, but considering the long run, it can certainly affect its efficiency.

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