Six Electric Cars Can Power an Office Building

cartechboy writes "How many Nissan Leafs does it take to power an office building? The answer, it turns out, is six. Nissan is the latest Japanese automaker to explore electric "vehicle-to-building" setups, this time with impressive results. The company started testing its latest system at the Nissan Advanced Technology Center in Atsugi City, Japan, during the summer. It found that just six Leafs plugged in to the building's power supply allowed it to cut peak-hour electricity use by 2 percent. Annualized, that's a savings of half a million yen (about $4,800 US) in electricity costs. How it works: The building pulls electricity from the plugged-in vehicles during peak-use hours, when power is most expensive, and then sends the power back to recharge the cars when grid prices fall. Nissan says the system is set up to ensure the cars are fully charged by the end of the workday. (Is this a devious secret way to make sure workers stay until a certain time?) Next up: Why not just do this using batteries--never mind the cars?"

Comments

Electric cars are impressive power houses

[ZorinLynx]

A Tesla Model S sitting in a garage has enough energy onboard to run a typical single family home for many days. It's pretty impressive just how much energy our automobiles use when we're driving them; they put the power consumption of homes and small buildings completely to shame.

Re:Electric cars are impressive power houses

[Anonymous Coward]

Or to put it another way how little energy most things need. You don't need tons of power unless you're trying to heat somewhere or move heavy things.

Re:Electric cars are impressive power houses

[LoRdTAW]

During Sandy we needed a temporary backup generator at work. We have multiple electron beam welding machines, electric heat treating oven, laser welding machines etc. Our building service is 1200A 120/208 three phase which works out to roughly 432kW. We pull about half of the panel rated load, or 600 amps on average and close to 800 peak. A towed 500kW CAT genset was hooked up and had a 15 liter engine, same as a the average semi truck. Ran the whole building without breaking a sweat. So a semi truck can run a small factory.

1HP is roughly 746 electrical watts. the Nissan Leaf has a 110HP motor which uses ~80,000 watts at peak output. The average American home has a 100 or 200 amp 120/240 electrical service. 240V * 200A = 48,000 Watts, which isn't used constantly but with enough creature comforts, consumption can run pretty high (AC, electronics, lights, appliances, pool filters etc.). So when you put your foot down in the Leaf, you are pulling 2x - 3x+ more current than a household can provide. Gives you some perspective.

cut peak-hour electricity use by 2 percent

[Saethan]

How many Nissan Leafs does it take to power an office building? The answer, it turns out, is six.

cut peak-hour electricity use by 2 percent

So the answer, it turns out, is actually 300.

Re:Billing?

[Anonymous Coward]

Also for the wear and tear on the batteries caused by the additional charge/discharge cycles. Batteries can only handle a limited number of cycles so this'll shorten their life. Those batteries aren't cheap either.

Re:Why not batteries

[Mr D from 63]

few business want to spend $120k on batteries.

I wonder how much power they would save by investing $120K in energy efficiency improvements? My guess in >2%

Re:Check that title

[pla]

Looks like 6 cars can offset about 2% of this office's power usage. Hardly 'powering' the whole office.

You misunderstand - Businesses don't pay for electricity like residential users. They pay by usage per demand timeslot. So they may pay a rate of $0.05/KWH for 80% of the day, $0.12/KWH for another 18%, then for the remaining 2% (around 15 minutes) that shoots up to $0.45/KWH.

This study found that you can run the entire building for those 15 peak demand minutes on six cars. Those 15 minutes amounts to way more than 2% of the business' electric bill (more like 10-15%), however, thus the huge net savings.

Company cars

[TWX]

I don't think it's intended for rank-and-file workers to supplement the company's electricity, it's probably more that higher-ranking employees with company cars would end up doing this.

If work gave me a car to use for several years, I don't think that the negligible electrical costs that I might incur at home would be enough to make me bat an eye at such an arrangement.

Re:Why not batteries

[VernonNemitz]

Not to mention the well-known fact that batteries have a limited number of discharge/recharge cycles. So, when the batteries in the cars eventually fail, the car-owners have to pay to replace them, not the building-owners.

Re:Why not batteries

[TheCarp]

well the problem, of course, is that the savings were less than 5k/year. That is less than 1k/year/car

This doesn't leave much room to both benefit the company and provide much bonus before you even figure that this may decrease battery life span. Of course, it also has to be offset by the fact that its also a "top off", presumably the cars drove in, so are not fully charged at the start of the day.

Maybe it works out, but its not a lot to work with for starters.

Re:Why not batteries

[Anonymous Coward]

There are companies that will do this. I worked for one (that I shall not name). Basically, the company would audit the business's energy usage and come up with a way to save energy (efficient HVAC, lighting, electrical, low-power standby etc). Then, they would make a proposal to split the cost in savings. So all the money is fronted and the business receiving the service pays nothing. The net result is one company saves money, the other earns a profit from a portion of the savings. Win Win.

Re:Why not batteries

[Anonymous Coward]

The other problem is what happens in the event of an emergency (wife goes into labor, kid gets suspended at school, etc) and you don't have a full charge due to the building syphoning power off intending to put it back by the end of the day.