Six Electric Cars Can Power an Office Building 296
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?"
Why not batteries (Score:3, Insightful)
The batteries in a Leaf are a significant fraction of the price, few business want to spend $120k on batteries, when they can get them for 'free' from their workers.
Re:Why not batteries (Score:5, Insightful)
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:Why not batteries (Score:5, Interesting)
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 (Score:4, Interesting)
One of the taller buildings close to where I work has six windmills mounted on top. You can often see them twirling away. The local alternative paper did an article on them once. Apparently the building receives up to 4% of their total energy from the windmills. This is a LONG way from "windmill powered buildings", (although is a higher percentage than what I expected) but it does serve another important purpose: From most of downtown, you can see that the building owners have put up windmills. This is apparently important enough that the actual savings wasn't a consideration.
Re:Why not batteries (Score:5, Insightful)
Re:Why not batteries (Score:4, Interesting)
If the car owner does all charging at the office, the cost of electricity would offset at least some of the cost of replacing the batteries. But I don't know that it would be worth it. This blog post [blogspot.com] suggests that the average cost per month of electricity is less than $50 for fairly average use, but the battery replacement program for the Leaf is $100 per month [autoblog.com].
Then again, the car owner would have to replace their battery after so much usage anyway regardless of where it is being charged, so assuming the employer's usage causes about twice as many recharge cycles, the employee might just break even.
Meanwhile the business gets a win by fully charging the cars when at non-peak usage, say around $0.05/KWH, and fully discharging during peak usage, say around $0.45/KWH, even if they have to supply twice as much energy to the cars as they use to power the office. (I pulled those $/KWH numbers from a post below; I have no clue if they are legitimate.)
I probably wouldn't participate in this program unless the employer provided a bonus incentive.
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If the car owner does all charging at the office, the cost of electricity would offset at least some of the cost of replacing the batteries.
Why on earth would you assume that it would be free to charge your electric car at the office? Do you get free petrol (sorry, gas) from your employer? I would assume, outside of this scheme, that car charging points everywhere except at home would be operated with a credit card. In a scheme like this I would expect the employee to get a monthly bill based on the net kWh they had drawn (or monthly credit, if that were negative).
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Actually yes, many Japanese companies do offer free charging for employees. Even in the UK there are quite a lot of free charging points at big shops that have solar fitted.
As for battery life span, it isn't affected much by partial charge/discharge cycles at slow rates. The 8 year warranty on Nissan batteries covers full charge/discharge cycles every day. Nissan is actually marketing it as a way to reduce costs because if you do need a new battery after the 250k miles it is rated for the energy savings wil
Re:Why not batteries (Score:4, Interesting)
They just need to use the Renault clone of the Nissan. You get the same battery but the car owner leases it from Renault, so they are the ones stuck with the cost extra failing batteries (and will certainly not pass it down to customers, right...).
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The purpose is for self-generators to not get scammed. Residential customers were producing power at some point whereby they'd draw 150kWh and put back 200kWh, but they'd be charged 150kWh@10c retail and paid 200kWh@6c wholesale. Paid 1200, charged 1500, they now owe the power company 300 for supplying 50kWh.
To fix this, the power companies are now required to credit you at retail price for the power placed on the system. It costs you 10 cents to draw a kWh? Well you get 10 cents to supply a kWh.
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Why shouldn't the workers get a tidy bonus for providing an extra service to their employer? Electric cars mean having a nice battery pack travel with you wherever you go.
Re:Why not batteries (Score:5, Insightful)
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 (Score:4, Insightful)
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.
Re:irreplaceable (Score:3)
So let me guess, you're one of those "IT bridge trolls" who build and hide in indecipherable structures and hoard troves of secret passwords, holding their organization for ransom, and mumbling and grumbling to themselves.
While thinking they're pretty damn good at their job, they are actually a worst nightmare scenario waiting to happen.
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I'm still trying to get a second sysadmin here because I have too much critical knowledge I can't adequately pass on. My job security is ridiculous, but the business is in a precarious position: if they lose me, major production revenue streams are in jeopardy immediately. I send out e-mails to managers and coworkers with reference instructions to keep things running and make them run again if they fail, so hopefully they can hold things up and redo it from scratch (they don't have the skill or expertise
Re:Why not batteries (Score:4, Insightful)
The batteries in a Leaf are a significant fraction of the price, few business want to spend $120k on batteries, when they can get them for 'free' from their workers.
The cost of the batteries is small in comparison to maintenance. Managing the batteries means hiring someone with that knowledge or paying for training/other development to get it in-house...at which point, those people would become more desirable on the job market as more buildings installed battery systems, increasing cost of retaining that talent. Then there are the business processes that need to be developed, the provisioning of a room to store them (and OSHA/building code concerns around a room full of batteries, which is no minor thing), and so on.
Or, they can just use the cars parked outside, offloading all of that effort to the owners of the cars.
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Managing the batteries means hiring someone with that knowledge or paying for training/other development to get it in-house...at which point, those people would become more desirable on the job market as more buildings installed battery systems, increasing cost of retaining that talent.
Oh my god! People! How I hate them! Always in the way of making good money. We should kill everybody in the world and just become ultra-rich. Oh, wait...
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offloading all of that effort to the owners of the cars.
And eliminating a good deal of it, too.
The owners aren't going to be doing the engineering to safely house the batteries, nor will they be installing the monitor system to detect problems, nor becoming experts in the maintenance and electrical construction of battery systems. That's all been done already by the vehicle manufacturer, and the work has been paid for whether or not the company uses the batteries.
What's offloaded to owners is the cost of consumables, like the charge/discharge cycles mentioned he
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Forbes calculates the price of a Nissan Leaf battery [forbes.com] to be between $7,700 and $3,888. So the cost is, at most, $7,700 x 6 = $46,200.
Billing? (Score:2)
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Now get off slashdot and back to work.
Re:Billing? (Score:5, Insightful)
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.
Company cars (Score:5, Insightful)
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.
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Screw that. (Score:3, Insightful)
Re:Screw that. (Score:4, Insightful)
Yes, and if the batteries are a significant part of the price of the car (true today), this is potentially moving significant expense to the car's owner.
Electric cars are impressive power houses (Score:5, Informative)
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 (Score:5, Interesting)
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 (Score:4, Interesting)
I've also considered building a battery room if I ever put solar on the house. Even running HVAC equipment it's doable.
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In that case the truck's engine is too big and you'd get better efficiency running the engine of a smaller car at a higher speed. Alas, VW 2.0L diesels don't have power take-offs, as far as I know.
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A Tesla Model S sitting in a garage has enough energy onboard to run a typical single family home for many days.
You *can't* be right.
It costs about $5 in electricity to get 200 miles out of a Tesla.
How many days straight do you think you can power my air conditioning from $5 worth of electricity?
You might be able to keep my lights on and power my appliances, but there's no way on this planet you can heat or cool my home for three days on $5 worth of electricity.
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Re:Electric cars are impressive power houses (Score:5, Informative)
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.
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A Tesla Model S sitting in a garage has enough energy onboard to run a typical single family home for many days.
It would be nice if there was a cheap and easy way to hook up your electric car to power your house during blackouts.
Check that title (Score:4)
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They can do it with 6 but it requires the help of 294 friends
Re:Check that title (Score:5, Informative)
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.
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Re:Check that title (Score:4, Insightful)
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Until everyone does it and the pricing structure changes.
cut peak-hour electricity use by 2 percent (Score:4, Informative)
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.
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I want to see you run that experiment, because I'm wondering if the connector will melt before the battery explodes, or if you're just going to current-limit harmlessly.
Externalizing the cost of maintenance (Score:3)
Simple answer: It costs a decent amount of money to buy and maintain a large battery array. Anyone in charge of a medium sized corporate server room can attest to that.
By "letting" workers plug in their electric vehicles, the company not only gets to bill it as a perk of the job, but they get to push 100% of the expense of maintaining those batteries onto their workers.
TLDR: Money.
Re:Externalizing the cost of maintenance (Score:4, Insightful)
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Wouldn't this just change the hours when peak usage occurs and result in the power company expanding peak hour charges or increasing the charges across the board?
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Not really - In fact, it could potentially eliminate having an actual peak period if enough companies did it, by smoothing the demand curve out over a much longer period of time.
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I would imagine that in order to maintain profit margin there would be a small overall increase in price if peak charges where eliminated. Would that equate to a larger bill I don't know.
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Annual savings 5k cost of 6 battery packs about 72-180 k (Telsa S 12k battery in the future buy now vs insurance replacement cost). In other words if they had to buy the battery packs it would cost them 7-18k a year for an average 10 year life span. Deep discharge lead acids would be cheaper but you get the point.
All in all lots of battery packs getting plugged into the grid has some interesting potentials. Nearly of them them require more intelligence than whats available and pricing the more closely mo
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I don't know about Japan, but in Europe it's common for leased cars to be a job perk.
So the company may use the cars that they are already paying for (leasing only, no battery replacement problem) to save money when these employees are in the office.
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By "letting" workers plug in their electric vehicles, the company not only gets to bill it as a perk of the job, but they get to push 100% of the expense of maintaining those batteries onto their workers while actually saving them money.
There, fixed that for you.
See, at the end of the day, the employees are able to drive home with a fully charged car. Said employees have already decided to invest in the electric cars, it's infrastructure that's already paid for. This deal effectively lets the company use their employee assets in a way that saves said employee money.
It's a win/win, unless said usage causes the batteries to degrade inappropriately.
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> Anyone in charge of a medium sized corporate server room can attest to that.
So don't promote it as a building power plan.
Promote it as an Extreme UPS.
Why not just do this using batteries? (Score:4, Insightful)
"Why not just do this using batteries--never mind the cars?"
Batteries have a limited number of recharge cycles, and they are very expensive (1/3 to 1/2 of the cost of the vehicle.) It's much easier to stick those expenses to the employees.
Other than that, yes, it would make a lot of sense to use stationary batteries. They wouldn't have to be light and small, for one. However it remains to be seen if the saved 2% is enough to pay for all the equipment.
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It's a good idea, but you don't use batteries for this. They are horrible. The charging losses will be greater than your savings; the batteries wear out; they are ecologically harmful to produce and to recycle, and they are expensive. There are industrial setups that achieve the same goal. They often use reversible motor-generators that pump water uphill during the night and produce energy during the day. Water does not wear out, so the only replaceable part in this setup is the bearings of the propeller (
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A company in the Chicago Loop (downtown office district) does something along these lines for cooling.
Company site:
http://www.thermalchicago.com/ [thermalchicago.com]
Video describing the system:
http://www.youtube.com/watch?v=ziEbY0oLf-o [youtube.com]
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It makes sense because the batteries are already sitting there, in this hypothetical scenario in which the average business has that many EVs sitting around in front of it all day which is actually highly likely. And perhaps the company could simply offer those vehicles to employees on some sort of basis, such as under a lease or as a reward for performance, and write the cost of their ownership off entirely and be able to reap the benefits of having the power storage on hand.
Super Capacitors (Score:4, Interesting)
The idea to store all excess electricity is already being investigated. But they're planning to use super capacitors rather than batteries. The idea to buy it cheap at night and sell it back to the grid during the day when theoretically, your consumption is lower (not at home, etc.) is too good not to be exploited.
Free infrastructure for the companies (Score:2)
Its like super sized BYOD except in this case it is bring your own load flattening system.
The company is only saving money on its power bill because its employees are freely lending them the hardware that they invested their own money in.
Not only that the company is not even paying depreciation on the reduced number of battery charge cycles the employees will see.
What they really need to study... (Score:2)
...is how many Nissan Leafs it takes to power an array of Nuclear reactor cooling pumps just in case of a Tsunami, Earthquake, Volcano, Mothra, Gamera or a Howls Moving Castle incident.
And the battery wear? (Score:2)
(Also, given charge/discharge inefficiencies, is the delta between on and off peak really high enough to justify that sort of thing?
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In short, no, this is a silly publicity stunt.
Batteries in cars are optimized for weight and cost at a moderate level of normal power draw. They are not optimized for powering buildings.
This is silly.
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I might blame mere stodgy conservatism, except that on-peak/off-peak and capacity optimization in heat
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BTDT (Score:2)
"Next up: Why not just do this using batteries--never mind the cars?"
NGK make large storage batteries and they use their own products to power an office complex in Japan, doing just what the article suggests by storing overnight lower-cost electricity in a large battery pack [ngk.co.jp].
Apparently it two weeks for the resulting fire to be extinguished.
NGK have sold a bunch of these batteries around the world, including to support wind power [shetlandtimes.co.uk] in the Shetland Isles in Scotland.
Positioning such a battery a couple of met
Scale (Score:2)
Edge Use Cases (Score:2)
Remember, on Slashdot, perfect is, and must always be, the enemy of good.
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Actually in this case it would be more interesting to flip that argument and find the edge cases in which this idea works and is viable.
Anyone?
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Not sure if the utilities will allow people to connect their vehicle chargers to an off-peak meter (like is used in some places for electric water heaters).
Charging the car at night and using the stored energy to power some of the load during the day (when the car isn't away) might be viable.
Interesting trade-off (Score:3)
The company gets to benefit from the flattened power demand and the employees get to charge their cars. Seems like a win-win to me. The additional wear on the batteries is likely minimal considering that there will probably be many more than 6 electric cars in the lot.
I doubt $4800/yr in electricity cost savings will fully offset the charger installation and maintenance costs, but it could be close enough that it can be justified as a marketing tool or as a perk to draw employees.
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Key point:
Batteries can only last so much cycle.
- It is to make sure workers stay until a certain time, like JAPAN.
A tank of diesel + generator would work too (Score:2, Insightful)
Stream that diesel from your car/truck's gas tank into the generator's gas tank, and you're all set.
Power companies need to think bigger. (Score:2)
Take an autonomous-driving system with enough of the bugs worked out. Put it in a semi cab, pulling a trailer full of batteries. Build fleets of them.
Every morning, they filter into the city, tethering themselves to various load-transfer facilities. All through the day, they help to level out demand peaks.
At night, they filter out, and flock around whatever generating plants are hardest to throttle up and down -- hydro, nuke, whatever -- and refill themselves.
What battery price/performance levels would we h
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The problem with batteries in this case is that they are expensive. They needed 6 cars worth of batteries for the load balancing that sav
Change in supply/demand in the future? (Score:3)
Right now, peak prices are during peak demand, which is typically in the afternoon. However, there are two factors that may change this over the next decade.
In many places, solar power will soon be a significant portion of the power supply, and solar production matches peak demand. Solar is a sunk cost, so any dynamic pricing is based on being able to scale back production at gas-fired plants and the like. Hence, it may be that power costs will be higher when it's dark, even if demand is lower. Expect peak prices in the evening and morning hours.
Also, as electric cars become a significant portion of the vehicles, demand for charging at night will go up significantly, so peak demand may well be at night. Utilities will certainly work to get car owners to install smart chargers that optimize charging based on power availability with the goal of a full charge by a certain time (such as when you typically leave in the morning). [And of course, by "full," that means 80% to maximize the life of the battery unless you're planning a trip.]
Of course, the combination of widespread adoption of both solar power and electric cars suggests that the optimal time to charge is during the day, but good luck getting that to work for the majority of workers.
Isn't this a waste? (Score:2)
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Added wear and tear on batteries? (Score:2)
Already being done. (Score:3)
Homes and smaller offices can do this too, but it would require dual pricing of electricity. The thing that stops these technologies from coming to homes is the single flat rate we all pay for electricity. If we price it like the old phone systems, peak/off peak, people would adapt and they will invest in load balancing appliances. Doing the laundry and the dishwasher at nights, cooling and storing cold water overnight to blunt the peak energy demand,... People will do all these things, if we make it worthwhile for them to do it.
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But peak/off-peak pricing is itself an artificial circumstance caused by inadequate infrastructure.
Re:Already being done. (Score:4, Interesting)
We know people waiting for 9pm to make long distance calls don't we? There were times we would yack on and on during weekends but be curt and to the point during week days before 9 PM. So yes peak load pricing would work. If you make it worthwhile. And what is not worthwhile to someone above 400% of FPL would be very much in demand by someone below 133% of FPL.
If one can make ice in the basement at nights and use it to cool the house in the summer day, 10$ a month savings would be worth it to someone, cutting the bill by half would be worth to someone else.
Abuse always saves dollars (Score:2)
Slavery was always cheaper than actually paying employees. Abusing employees' cars, destroying the batteries and wearing down the electronics in a never-ending charging loop every work day is obviously cheaper than buying your own batteries.
Cradle to grave is always a very different calculation -- one that most people never make.
Compare with other time-shifting methods (Score:2)
As is pointed out regularly on other /. threads about alternative electricity generation, it's possible to draw electricity during low-cost time periods and store the energy either directly or indirectly. So how does the cost of what's basically a large battery backup system compare with, say, a pump, a large water tank on top of the building, and a dynamo?
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As is pointed out regularly on other /. threads about alternative electricity generation, it's possible to draw electricity during low-cost time periods and store the energy either directly or indirectly. So how does the cost of what's basically a large battery backup system compare with, say, a pump, a large water tank on top of the building, and a dynamo?
It might be less efficient. Each time you convert the energy you are taking some amount of loss to heat/friction. For large scale systems i was under the impression that water-gravity systems were much more efficient than batteries.
Awesome, this will actually be economical when... (Score:2)
Cheaper? Easy (Score:2)
Electricity prices are higher during the work day, lower at night. The employees drive the car home and it gets charged overnight in their home on their own power bill.
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Electricity prices are higher during the work day, lower at night. The employees drive the car home and it gets charged overnight in their home on their own power bill.
Not for the vast majority of American households. Wholesale electrical rates (grid costs), commercial and industrial users have time of day differentials. This is deemed too complicated for home consumers so they just average it out and charge a flat rate.
Lease the car and the batteries (Score:2)
Many companies lease cars to their employees. They could include some kind of battery-sharing deal in the contract. This may actually lower the price of owning the cars as they can be seen as part of the power system.
Yes, but... (Score:2)
I don't think so... (Score:3)
Peak usage during the summer hits very late in the day, after 3PM or so and does not start to fall off until after 6PM. Off peak electricity rates therefore don't start until "evening" hits.
Assuming they tapped out your leaf between 3 and 5, then started charging it at 6, you would only be up to 80% charge by 6:30 PM using the "fast charge" option. Full charge would take over an hour to complete using a fast charger. So, your work day will likely end after 7 PM to make this work very well.
Sorry, I'm not working from 8AM to 7PM every day, nor am I going to let you discharge my car and strand me at work between 3 and 7 pm. Now if you want to supply the car.... We can talk, but I'm going to be starting work at 10 AM or something..
Strategies like this will work fine, for a while (Score:2)
Once enough people start buying and storing electricity from off-peak times, the power companies will complain about not making enough money, and a price increase will result. Mark my words.
Same as water authorities, they yell at everyone to conserve water and then they raise prices because they no longer have enough income..
Self defeating? (Score:2)
In the case where this becomes popular or common place in an urban centre, wouldn't the process of discharging, and then immediately recharging after peak power times, cause the peak power times to shift due to the demand for recharging - eventually negating any benefit?
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Duh, battery life is almost exclusively charge/discharge cycles, so the office building is putting very significant costs onto the car owners.
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