The vast majority of people will usually charge overnight and don't need to regularly charge at peak times. Through intelligent charger management, you can distribute the load of charging across the entire off-peak period. The UX for this can be fairly straightforward - by default you charge at the cheapest rate, or you can press a button to get the quickest possible charge.
The real dividend comes from bidirectional charging, using the collective resources of plugged-in cars as a load balancing reservoir. In exchange for a discount on your electricity, the grid can take a small percentage of your EV's battery capacity when needed. A typical mid-range electric car has a 40kWh battery, which represents about four days of electricity consumption for a typical European household.
Nissan and the British utility regulator ran a two-year trial to examine the long-term impact of EVs on local grid infrastructure. The trial used intelligently-managed unidirectional charging. They concluded that about 32% of local electricity circuits will need to be upgraded by the time that EVs represent a majority of vehicles on the road. This figure could potentially be lowered further by bidirectional charging technology.
America still has huge potential for efficiency savings, because of the immensely high average household electricity consumption. The average American household uses nearly three times as much electricity as the average European household. Air conditioning is only a small part of this disparity, representing about 18% of the electricity consumption of American households according to the Energy Information Administration.
Currently utilities buy power during peak times from other utilities, or fire up expensive peaker generators to manage the load.
A network of charging cars could be managed as another resource with a price attached to it that may be cheaper than the alternatives. I like the concept of varying the price of the charge based on your participation in the network.
At least in Florida, USA, most residential electric meters are flat-rate (same price per KWh, no matter what time of day you are using). A good portion of commercial meters have a peak and off-peak rate, as well as a single line item charge, based on peak demand, that is often 30-40% of the entire bill. The off-peak rate is often 50% or more cheaper than the peak rate.
Since most people would charge at night, it would probably make sense to have these residential services switched to a demand and time-of-day based meter, which would further reduce the cost of electricity. If someone spends a significant time at home, the charging car could buffer peak loads during the day to offset the additional draw of the nighttime charging.
Also think about when peak demand happens -- late afternoon on hot summer days. Right at the time when people are getting home, with their EVs discharged (or at least, not at full capacity) after a day's use.
The grid is already perfectly capable of consumer feed-in, hence the huge deployment of photovoltaic solar systems. The metering is not particularly difficult. There is an emerging standard for smart grid communications (LTE on the 450MHz band) that is already in widespread use across the EU.
Completing this transition won't be cheap, but there are no significant roadblocks. We know what needs to be done and we have the technology to do it.
https://www.drive-electric.co.uk/driveelectric-launches-vehi...
http://www.energynetworks.org/assets/files/electricity/futur...
http://450alliance.org/wp-content/uploads/2014/05/WhitePaper...
Not completely discharged - the little available per car will add up to a lot when there are a lot of EVs. The EV owners who decide to sell to the grid at peak hours (at higher prices) might make a profit doing so.
Long story short: NRG wanted to build a natural gas peaker plant, California Energy Commission said "can you do this cost-effectively with storage?", NRG said no, then people realized the "no" was based on 4-year-old battery figures. With updated figures (storage follows a manufacturing curve where the more we build the cheaper it becomes, so prices are dropping every year just as they've done with solar), turns out that yes, storage is a potentially cost-competitive alternative to nat gas peakers.
The application to build the plant is on hold to let the battery folks submit a few bids, I believe, but the econmic trends are clear: you can do peaker plants with storage now (or at least very soon).
It's just a matter of safety margins and probability. Traditional powerplants break too, and with enough cars the probability that enough of them wouldn't be available at once is smaller than the probability that enough powerplants break at once.
https://energy.gov/oe/services/technology-development/transm...
We will see far more volatile supply, because of the less reliable output of renewable sources. Supply and demand need to be perfectly balanced at all times to prevent brownouts or outages. Balancing supply and demand will become more challenging as we start to take fossil fuel generators offline. This is where smart grid management becomes vital.
EVs could adjust their charging rate in real-time, drawing maximum current when prices are low and discharging at a high rate when prices spike. Smart air conditioning units and refrigerators could respond to pricing on a minute-by-minute basis, running their compressors when electricity is a fraction of a cent cheaper and allowing the temperature to drift upwards by a fraction of a degree when prices are slightly higher. Industrial consumers could pause energy-intensive processes when prices are high and store power locally in battery, pumped water or thermal storage when prices are low.
A slightly extreme example from the UK is the notorious TV pickup. We drink lots of tea and use 3kW electric kettles to make it. During the commercial break in popular TV programmes, there's a surge in demand that often reaches hundreds of megawatts as millions of people simultaneously switch their kettles on. The national grid employ a dedicated team to manage these rapid demand spikes. They study the TV schedules and continuously monitor the grid frequency, turning on extra generation capacity and drawing from pumped-water storage to balance the extra demand. With smart grid technology, the TV pickup could be automatically managed through a real-time market.
Edit: lol, I get downvoted for relaying what a professor of EE told me. Stay classy HN.
TOU (Time of Use) rates are becoming more and more common.
In 2019, TOU rates will be the default rate structure for new accounts in California. Many more states are following suite.
Even if they're not the default, tons of places have opt-in TOU structures. EV owners and home storage owners use this a lot.
Some states have even already adopted complicated shit only seen in C&I customers: demand charges. Basically, a portion of your bill will be dependent on your peak demand during a period (ie peak kW, not total kWh).
I think this is the way things are moving in other jurisdictiins as well. In case of Germany and France one of the reasons why the systems have mot been upgraded lies in the privacy rules for the power consumption data according to one smart meter manufacturer.
Not just that, in addition the smart meters cost a bunch of money to install... people don't like paying anything very much.
Norway is going all-in on smart meters, installation has been rolled out this year to ~80% of the country, due to reach 100% next year. The total installation cost is estimated at around 2.5 billion USD for around 2.2 mill. houses, i.e $1000 per house. Which of course we as consumers will be paying for through higher electricity prices.
This is still the case, see: http://www.nyseg.com/YourHome/pricingandrates/daynighrate.ht...
Perhaps you misinterpreted the scope of applicability of what the professor said.
I have a plan which charges significantly less during off peak hours.
Something as modern as time-variable tariffs... not gonna happen soon here.
The electrical grid is already sized for peak usage, not average usage. Supercharger stations are also being sized for peak usage, and most of the stalls usually remain empty. Incorporating stationary storage cuts down on the costs incurred by both of these inefficiencies.
at the cost of 10% more power usage due to the inefficiencies of charging and discharging batteries. Might still be worth it from an electric company's bottom line, but in most markets, it increases greenhouse gas production because we need more kwh of power.
Either we get a grid that's intelligent enough to balance stuff out or the grid has to be built out with massive reserves, and that's everything but not cheap.
You can do the same solar energy and cars plugged in during the daytime, soaking up excess solar electric generation.
Microsoft provide the api for knowing in advance when energy will be the greenest: https://api.watttime.org/faq/
Some utilities will give you rebates if you use a smart charger to charge at these times (since green energy is both cheaper and time sensitive).
https://emotorwerks.com/products/juicenet-software/juicenet-...
However, in regards to cities, you are presenting a situation where the charging station comes to the parked car, rather than the car going to the charging station. While that would be quite convenient, if the charging times are rapidly decreased, there’s no reason car owners in cities would not be able to drive to stations to charge up, as drivers do with gas stations today.
Charging times have an upper bound: physics. 250 kW is an insane amount of power and still you'd need around half an hour to fill a 100 kWh battery, to get even close to the 5-10 minutes of charging like at a gas station you'd need megawatts of peak power... and as there are two steps of conversions involved (grid => HVDC => battery voltage), even with 99% efficiency you have 1% (or 10 kW) of heat loss alone. That heat in the small space of a battery pack is a challenge.
Gasoline has about 33kWh per gallon. A typical gas pump is limited to 10 gal/min flow rate (lets say 8gpm just to be conservative).
That means your gas pump takes about a minute to dispense 250 kWh or 23 seconds to dispense 100kWh. That generates effectively no heat. To charge one electric vehicle at the equivalent rate (assuming it could tolerate it) would take a 15 megawatt power source per 'pump'.
Here is the size of a one megawatt AC to DC power substation:
"The complete ABB megawatt station weighs only 20 tons. At 50 m3, the container’s volume is some 15 percent smaller than equivalent solutions."
https://library.e.abb.com/public/52d148c3c4b02ded85257e4c004...
I own an EV (hybrid really, Volt, but I'm 85% electric). I support electric vehicles enormously. But this is a huge huge problem with scaling that no one talks about. My volt can charge, slowly, at 8 amps (~1kW) while I'm at home, a rate my home power can easily take. Most vehicles in the US are static for at least 8 hours once, if not twice, during the day. Using that time to charge slower is a stopgap but I really doubt that the US grid has the excess capacity for this.
Yeah, there are efficiency losses along the way, but two points: - More and more net metering tariffs are homeowner-buys-at-retail-pricing-grid-purchases-back-at-wholesale-pricing... the homeowner value of solar's excess energy is getting less - In a lot of cheaper EV purchases, the car company still owns the battery packs. This is for two reasons: 1) They sell you on a new battery pack when your range starts to decline after a few years, and 2) They're going to use the degraded batteries as second-life storage products... maybe not good enough to power your car, but more than plenty to provide a cheap powerwall alternative.
The points you bring up about mass charging is true, but once pricing starts to reflect that, that's going to make home storage far more economical (it already makes economic sense in some markets).
My parents took us kids on car trips during summer holidays, and usually by the time we needed to stop to refuel the car we also took the time to eat and such.
I'm not disputing your point. It's a HELL of a lot more juice than people are used to thinking on a day to day basis. And it's going to change our infrastructure in fundamental ways.
> the charger delivers exactly what the car needs
You're both right. A Level 3 charger does deliver the right DC voltage the car needs, and it does so using power electronics that convert regular old grid AC into DC.
Level 1 & Level 2 charging: AC grid -> cable -> onboard charger converts to 400V DC -> battery
Level 3 charging: AC grid -> offboard charger converts to 400V DC -> cable -> battery
Same number of steps, same conversion efficiency. Tesla even goes a step further and uses the same hardware, building out the (low volume) Superchargers "simply" by ganging together a dozen (high volume) on-board charger modules and stacking them inside a weatherized outdoor cabinet. This commonality maximizes their economies of scale.
For anyone that's confused, it's because now we're really getting into the weeds of how the grid works. :) It's only fair to look back and compare from the same point in the grid, in order to be an apples to apples comparison. Really we should look at the whole electricity supply chain.
Level 1 & 2 charging: high voltage AC transmission line -> local substation converts to 480V AC -> distribution lines (poles or buried) -> pole-mounted or buried transformer converts to 110/220V AC -> household wiring -> cable -> onboard charger converts to 400V DC -> battery
Level 3 charging: high voltage AC transmission line -> on-site transformer converts to 480V AC -> offboard charger converts to 400V DC -> cable -> battery
Also few people keep their cars for 15 years. I think 5-7 years is much more normal (though perhaps you meant the total life of the car, from original owner to the last).
Personally, I keep cars until they're no longer reliable/economical but the average length of ownership is presumably lower and brought down by people who get a new car after a 3 year lease. Although the overall length of ownership has been increasing because of improved quality.
Given the trend (in Germany) to crack down on ICE cars, you're looking at a way shorter timeframe. Once the first court OKs ICE bans, stuff is going to get nasty.
They then had to issue a second report pointing out that their first report said it wasn't going to be a big deal.
http://fes.nationalgrid.com/media/1264/ev-myth-buster-v032.p...
The USA spends $500Billion on cars and $400 Billion on gasoline every year. A onetime $trillon upgrade isn't an outsize amount.
Because a TV coax cable is 1cm slim and can be installed very easily. Run it over the air on poles, dig it into a small trench, run it via the sewers. Whatever fits best.
A 10 kV or, worse, a 1 kA-capable 3x230V line, not so much. The 10kV (or more) line has special requirements in terms of distance to other cables, a 3x230V line at that capability is pure hell due to its sheer thickness and mass.
Also the charger station will require a transformer... which aren't tiny, and transforming 250kW produces significant heat loss. So either find some free place in earth where you can bury it, or deal with adjacent house owners to install the transformer in their basement.
> The USA spends $500Billion on cars and $400 Billion on gasoline every year. A onetime $trillon upgrade isn't an outsize amount.
Problem is, the car/gasoline spend is done by individuals on small-ish scales. A multi-trillion investment must be fronted by the state - the utility companies don't have nearly enough cash to finance this. But, as noted, the US can't get enough funds to replace Flint's potable water infrastructure or Puerto Rico's broken grid...
1) with $2k you can barely have the trench from your house to the core cable in the street digged. Better calculate 10k.
2) Why the fuck should I pay my employer to put in a charger in the garage? This will, alone for the electric work, add another 1-2k on the bill.
FWIW all of the chargers I've seen didn't require new transformers or lines. Heck they put in 20 spots in Centralia without even digging up the road.
Heck, when I bought my current house I didn't need to do anything since the previous owner already had a NEMA 14-50 outlet for their welder.
Los Angeles and parts of the Bay Area have had nearly annual brownouts for the last 20 years just from air conditioners during heat waves. How in the world do you expect that aging power grid (in the fifth/sixth largest economy no less...) to handle a clothes dryers in every house running 4+ hours a day?
Fortunately those "clothes dryers" are already connected to the internet, and have sophisticated power electronics hooked to the grid that can detect voltage sag and phase lag. Connected to a central server, each car (or stationary battery, for that matter) becomes BOTH a sensor that can monitor grid health AND a remote-control load that can be dialed up and down (so long as the car gets a full charge before 7am, or whenever the user chooses).
The internet allows entire neighborhoods of EVs to be controlled at once, so that the substation is at 100% power and no more, and so the distribution/transmission lines are at 100% power and no more.
Is that a hard control problem? Sure. BUT it's easier than overbuilding the electric grid by 2-3x (which is, after all, the largest machine ever built[1]). And given the very large opportunity cost, there's a lot of incentive to solve it.
[1] https://www.smithsonianmag.com/videos/category/innovation/th...
With off-peak rates and people having different schedules(I'm home at 4pm for instance) I don't see why everyone would be hammering the grid at 5pm.
Of course as has been pointed out repeatedly a smart charger can manage exactly when the battery starts to charge. However it isn't quite that simple: many of those people will go out again for their bowling league or whatever, and need enough charge in their car.
Let me guess you're countryside? Friend of mine has a relatively new house in Munich, biggest thing he has is a 3x16A CEE outlet.
I'd happily use public transportation instead if I could but the closest one to me(12 miles away) was the one that derailed yesterday.
EV charging infrastructure isn’t yet well suited to medium to long road trips, so some people discard the whole idea because they’re upset by suggesting a different distribution of friction in their lives.
Whether the actual friction is big enough to matter is hard to say. I drive outside a 100 mile radius about twice a year, and I don’t mind renting cars when I do, so it doesn’t seem especially onerous to me, but don’t underestimate people’s love for their particular car/dislike of rental cars.
“The grid to your home can’t even provide enough power to charge your car” becomes a decent reason not to move there.
https://www.google.com/maps/place/Eagle+Mountain,+UT/@40.335...
I'm almost sure the county I live in now doesn't have cable TV anywhere. It costs a lot to roll out a network of anything. I'd guess a power network costs more than cable or fiber.
Let's assume average parking space area is 10 square meters (it depends, but it's close [2]) - so that's 7.5 kWh per day.
Average energy consumption of electric cars is 11-16 kWh/100 km [3], let's assume 10 kWh/100 km - that's 75 km range for a day of standing in sun.
That's actually not bad, and should be enough for driving back home from work. Actually, why not just put the solar cells on the car and do away with the batteries (car already has them). It would be less area, but even 20 km of driving for free would be enough for many people.
Hell, I use a car maybe twice a week, usually to drive for less than 10 km. Such a car would basically drive for free for my use case :)
[1] https://dothemath.ucsd.edu/2011/09/dont-be-a-pv-efficiency-s...
[2] https://www.quora.com/What-is-the-size-of-a-standard-parking...
[3] http://pushevs.com/2017/05/23/electric-car-range-efficiency-...
Because you might squeeze 200W worth of panels up there at best. On a sunny day you’ll get about 4 extra miles at the end of your workday. And now you can’t drive home with the sunroof open on that sunny day.
Tesla Model 3 gets 310 miles on 75kwh so call it 4 miles per kwh that's 40-50 ish miles per day if you can stay in the sun.
Current records for solar panels well over 40%, so a fully solar powered car may actually be possible even if stupid expensive.
PS: Those solar challange cars are getting impressive. http://solarteameindhoven.itility.nl/ is a 4 seater doing 60+mph though far from street legal.
Car companies are not adding panels because the benefit is not huge, they add complexity and cost, and panels negatively impact styling. Still, you see a lot of campers with solar panels on the roof because a few kwh/day of extra power really does add up over time.
You’re going to need those fans with giant, black heat sinks on your roof. To the point that I wonder if the panels heat the car faster than fans can remove it.
Still, you see a lot of campers with solar panels on the roof because a few kwh/day of extra power really does add up over time.
You see a solar panel on our VW camper because a 100W panel can easily recharge the battery that runs the 20W of LED lighting, and charge the occasional laptop, not run a 80,000W traction motor. My parents have a 35 foot fifth wheel with A/C, microwave, and other goodies. It has an option for solar panels. They didn’t buy that option because solar panels ain’t gonna do squat for that load. They figured it might buy an extra half day of boondocking before the house batteries run out. No, you see a lot of campers with solar because they either have a small load like us, or the salesman convinced them it would be a good idea on their 40 foot Class A tour bus.
A 120mm computer at full speed is ~6w and can move 75 cubic feet of air per minute. So, 20w worth of fans can quickly exchange a lot of air.
Anyway, 100W of panels is minimal if your using 20+% panels. You can get that from a 1.5 foot x 3 foot section, a camper can have 20 of those on the roof assuming your starting with mostly clear space.
Not everyone will benefit or care about charging their car a few less times per year and adding panels will cost more, add weight, and probably change the appearance of the car, but I think it's an option worth exploring.
Because that energy isn’t free. Panels cost money, the electronics to get it to the batteries cost money, and increased complexity cost money. You won’t get a sunroof. Those black panels that are specifically designed to optimize the absorption of the sun’s energy will absorb heat.
All so I can get an extra four miles (on a good day) of range after sitting in the sun all day. I’m not going to go as far as to say it’s a dumb idea, but it sure is hell isnt a good one with current technology.
There are two ways of making sure you still get power when there is no sun for your panels: storing power locally and using the grid. For storage, you can have enough batteries to deal with the day-night cycle, but a week of overcast weather in the winter is likely to be prohibitively expensive. It means that the grid is necessary, and it has to be able to cope with peak load.
There is a pilot current to establish the communication that coordinates this but it's nothing that would electrocute someone (probably similar to an Ethernet cable).
On the country side, laying cables for 1MW peak load (4 superchargers @ 250 kW) will be expensive - the grid in rural areas is enough for some farms and small villages, that's it.
In cities, electric-car chargers will have to deal with political obstacles (no one wants to sacrifice free-for-all parking spots!), in addition to the electricity problem - while in a city there might be more available 10+ kV lines (you don't want to do 250 kW over 230V AC, it's over 1k A current!), sidewalks are often enough very slim as it is and it will be difficult to get a charging station installed there, and digging in earth filled with cables is not exactly fun either (been there, done that, it's manual work of the worst kind as you can't even use a proper showel...). Getting chargers in garages will face obstacles of the HOAs, plus the house uplinks usually are without much reserves - my 12-apartment house, for example, is linked to the grid on 3x63A with each apartment (~60 m2) being fed by a single 40A phase. Not much, certainly not enough to feed even two electric cars in the backyard.
Either way you'l have to rebuild the entire grid more sooner than later if electric cars should have a future... there's not enough money to rebuild Detroit's water, where should the money for a full scale grid rebuild come from? It's all decades old infrastructure, no matter if in the US or Germany. Replacing or significantly upgrading it means billions to trillions of dollars.