Your Future Home Might Be Powered By Car Batteries (bloomberg.com)

Increasingly utilities and automakers are wondering if they could use the batteries inside electric cars as storage for the entire public power grid. An anonymous reader shares a report: The idea, known as "vehicle-to-grid," is to someday have millions of drivers become mini electricity traders, charging up when rates are cheap and pumping energy back into the grid during peak hours or when the sun simply isn't shining. If it works -- and it's a big if -- renewable energy could get much cheaper and more widely used. "We really, really need storage in order to make better use of wind and solar power, and electric cars could provide it," said Daniel Brenden, an analyst who studies the electricity market at BMI Research in London. "The potential is so huge." Today, fewer than one percent of the world's vehicles are electric, but by 2040 more than half of all new cars will run on the same juice as televisions, computers and hair dryers, according to estimates by Bloomberg New Energy Finance. Once cars and everything else are fed from the same source, they can share the same plumbing.

Comments

Take the car away

[iTrawl]

I thought they made a car specifically for this use pattern. And they took away the car and called what was left the "Powerwall". Sure, you stick it to a wall rather than ambulate it all over town, but I think it works out just fine.

Re:Take the car away

[ShanghaiBill]

The Powerwall costs extra money, but you will already have your car battery, so there is no additional capital cost other than an inverter.

My wife has a Tesla with a 240 mile range, and on 95% of days she uses less than 20% of the capacity. The rest could be available for energy price arbitrage.

The car starts charging at 2 am, when electricity prices are lowest. The power companies need to fill the gap from 4pm to 7pm when power use peaks, but solar is fading.

Re: Take the car away

[shilly]

Hence the powerwall

Re: Take the car away

[rmdingler]

A powerwall designed specifically to store and discharge energy to offset peak usage is also going to be more practical to market, since electric car owners would understandably be concerned about the number of charge/discharge cycles their batteries could sustain before needing replacement.

Re:Take the car away

[rhsanborn]

Not to mention that, at the moment, batteries are very specific to a particular car, which happens to be one of the largest capital investments a family can make. What kind of life-cycle degradation can we expect from the car being a base-load for the house? I'd hate to be reducing the life-expectancy of the car because it was used floating the house. I have a feeling a pack dedicated to the purpose would be better suited to the task, and much less expensive to replace when it wears out (as opposed to taking apart the car). It also doesn't fit the use case for most families. The house-supporting battery pack will need to supply most of it's power at night, but that's when the family is expecting the car to be charging to the next day's commute. When the house or grid is at full renewable production, your car is most likely sitting in a lot at work somewhere.

Re: Take the car away

[AmiMoJo]

The other big issue with V2G is that it needs to use much more complex charging hardware. The current offerings in Norway only work on CHAdeMO, for example.

I think it's more likely that people will use recycled car batteries in a PowerWall type product. There won't be a shortage of them from cars written off for other issues, and most of those packs will have a huge amount of life left in them.

Seems dubious

[Gavagai80]

The average age of a car on the road in the USA is 11.5 years. Personally, I drive a 1998. If only 50% of new cars in 2040 will be electric, then we're looking at sometime between 2050 and 2060 for a slight majority of cars on the road to be electric. So this plan had better work with a fairly small percentage of cars being electric, or it'll come way too late to do any good.

A better use of electric cars may be simply using their depleted otherwise-worthless batteries as part of the grid. That way you don't have to convince people to let their battery be worn down, either -- getting people to allow their car battery to be used to balance the grid will really require that they be getting free replacement batteries, because it can't be good for battery longevity.

Re:Build the base first, then expand

[thegarbz]

Let's first of all finish inventing the storage before we ponder spending the energy.

Lets not. If we spend our lives waiting for perfection before starting anything then we will never get anything done.

Re:Too much hype...

[Mashiki]

400v isn't dangerous though, it's the amperage that's behind the 400v that's dangerous. You can go and get hit with 10,000-50,000v right now pull the wire off a spark plug on any car, it'll hurt but it won't kill you even if it's grounded through you to the earth. Low amp, high voltage. But, you can kill yourself off the starter motor which can draw upwards of 300-900amps from that 12v battery. Haven't even started with home 1ph-120v, or 3ph-208v used in industry.

Country dependant

[DrYak]

In some country, petrol IS NOT the thing stations profit the most.

At least in several places in Europe, stations profit the most from their shops (selling snacks and other small useful item. At a high price than in the city, but more convenient or in an emergency, as they are open 24h and on your way on the highway) and their cafe (taking breaks is heavily recommended by massive campaign and even legally required in some driver professions)
In fact several chain of stations are actually owned by chain stores.

The petrol is mostly use as a way to attract people to the shops/cafes.

As soon as electrical cars became a thing some stations started to install charging station as a way to attract even more customer to the shops and cafes.

Re:Country dependant

[Mashiki]

That's true in most countries. The profit margin at most stations is pennies per/L, in Canada it's around 0.02-0.045/L. The US? Most stations make around 0.10-0.25/Gal. Thing is, here in Canada we have those charging stations in places like that and they don't draw people in. People simply leave their cars and fuck it up for everyone else. When it takes 30min-2hrs for a charge instead of 8mins for a fillup, you can already see the problems. In Ontario, if we had massive numbers of electric vehicles most small stations would need 40-100 bays to recharge. Distances are too large, the same in the US. Unlike Europe, people being on the road 5-6hrs for a commute is common all across north america.

An example: A person living in London, Ontario would spend 2.5-3hr/one way to commute to Toronto. It's cheaper to drive, then take the train or live in the surrounding communities(Brampton/Mississauga/etc where a starter home can be $1.4m+) in the GTA for most people, unless you're making a combined income over $150k/year. Even at that, you're going to find times where you're under that 60-day lose your job and lose your home. Even at that, you're probably considering finding a new place to live because you're being priced out of your own neighborhood. Another example, I was looking at house prices in Woodstock, Ontario. A house built in 1810, that is under 1600sqft(148sqm) with knob & tube wiring, galvanized pipes, maybe windows from the 1940's(single pane w/winter storm windows that have to be attached). Were running in the $340k range, the average income in Woodstock(and the county of Oxford) is around $43k/year.

These ideas are good in high-dense urban areas, anywhere else they fall flat on the realities of the world.

Re:Why?

[K. S. Kyosuke]

A car with ~200 mile range is going to have a ~50 kWh battery. My home uses ~2-3 kWh overnight. So by using the energy of a fully charged car overnight once, I am still at a 188-192 mile range. How's that a problem? Do you run a steel mill at home or something?

Fly in the ointment

[Solandri]

have millions of drivers become mini electricity traders, charging up when rates are cheap and pumping energy back into the grid during peak hours

Transportation accounts for about 70% as much energy consumption as electricity. If you convert all those ICE cars into EVs, the electric rates won't be cheap during the night when they're charging. Overnight will become the new peak consumption hours, when electricity is most expensive.

Don't tell this to my employer.

[LordHighExecutioner]

Or from a "bring your own device" policy, it will rapidly switch to a "bring your own battery" policy to further lower infrastructure costs.

Battery wear

[orzetto]

(Disclaimer: EV owner, researcher in relevant field, and I was once asked to evaluate a research project on V2G in an European country)

The idea is interesting, and may well have an impact in countries with a lot of non-controllable power (wind, sun, but to a degree nuclear and other baseloads too), if price oscillations are large enough. The article mentions a potential of USD 40 a month, which is just above a buck a day. Would you risk not having enough charge in your car to get home for such a pittance?

More importantly, there is no mention of battery wear. Batteries are much more expensive than the energy they store through their lifetime. Teslas have actually a very limited lifetime of about 500 cycles (since the batteries are large, there is no need for more lifetime—it's actually smart to use short-lived, cheaper NCA batteries as Tesla does), which means that, if you assume USD 200 / kWh by 2030, each kWh will cost 40 cents only in battery depreciation: that's a lot more than what the energy costs, and will likely more than offset those 40 USD a month. (Yes, there are longer-lived batteries; they are also more expensive) (Yes, battery wear is not just a matter of cycling, it's also storing at high voltage, rate of charge/discharge at which temperature, and lots of other things)

V2G is very interesting for grid companies as a solution to their energy storage problems, but they seem to intend to exploit the lack of consumer understanding of EV cost dynamics: the real cost of a kWh is the battery wear, not the actual energy. There is a reason why these companies are not buying the batteries directly.

I believe V2G has more potential in "private grid" applications: e.g. if you have a cabin in the woods with no option of grid connection, you could drive to it with you EV and power it from your batteries while you are there (a home uses a lot less power than a car); or you could transfer some charge to a vehicle that ran out of it on the road (actually the Toyota Mirai has a similar feature, a ChaDeMo outlet).

Re:Battery wear

[AmiMoJo]

Teslas have actually a very limited lifetime of about 500 cycles

Incorrect, Tesla use Panasonic cells rated for 3000 cycles.

500 cycles at 250 miles per charge would only be 125,000 miles, which happens to also be the warranty on the packs. Lifetime being a bell curve approximately 50% of packs would qualify for warranty replacement if that was the case. But more over, lots of Tesla cars are up to 200k+, and Tesla tested up to 750k.

Even the original Nissan Leaf has proven to be more durable than that, with taxi firms putting over 200k miles on the original pack without any problems. The newer 30 and 40kWh models might not last so long though.

Great Solution / Battery Wear

[foxalopex]

A lot of pure EVs store significantly more power than the average home uses in a day so there's a good chance it can be used to store renewable energy. Even if people can't get renewable power, they're valuable for levelling power use. Part of what keeps electricity costs high is that our power use swings wildly during the day so power systems need to be designed to generate more power than will ever be used.

Also most EV's use the much more reliable LIthium-Iron-Phosphate class batteries (https://en.wikipedia.org/wiki/Lithium_iron_phosphate_battery) which wear out at a much slower rate than most lithiums and rarely if ever catch on fire. Tesla I believe doesn't use these more reliable batteries but the trade-off is the ability to pack more power in a smaller space / weight which is why they have some of the smallest batteries for their incredible capacity on the market.

Physical energy transfer

[nitehawk214]

You could "fill up" your car in one location, drive home, and pump that power in to your local grid. If the local prices were high enough it could be affordable. You could get some sort of "energy truckers", hauling batteries across territory from grid to grid.

That would make things interesting, though I can't imagine it would be terribly efficient. It would encourage companies and governments not to build out proper electrical grids.