And practically useless as an EV battery is a different amount than in a stationary application.
A percentage of the power supplied to your house is green energy and percentage is not, and it will change day to day. Also if different by location. Live near a hydo power station more will come from the dam. Live near a goal plant more will come from coal.
Impact of EV charging at home. Depends on what time of day you charge and how many KWH you use to charge your EV.
About over loading the distribution system. It would depend on how much reserves the local power distribution has. About 10 to 15 years ago in the Santa Clara valley the reserves were very low. It was not was there power to purchase from out of the valley, if power was purchased there was no way to increase the amount of power that could be delivered . The system was at max capacity. PG&E had to do rolling black outs to keep the system from crashing. Power plants near the valley were running at 100% with no down time for maintenance. Since that time Calpine power plant was built and many homes and business have added solar to roofs.
So back to your question if everyone plugs in at the same time could it bring the system down, depends.
Our Tesla draws about 7000 W when plugged into our Level 2 charger at home. At that rate, it takes about 2 hours to add 100 km (60 miles) of range (ballpark figures, YMMV – literally!).
Typically my hubby will plug it in when arriving from work; so, very often, the oven is on in the kitchen at the same time that the car is charging. The car stops drawing power when the battery is at the user-defined “full” level (in our case, 85% most of the time).
The car has options to delay charging until, say, 8:30 PM, or to draw only 4000 W instead of 7000. Most days, this would be quite enough to get a “full” charge for the next morning. All of this can be adjusted on the car’s screen or using the Tesla application on our phones. Right now we only use those options when our power distributor asks everyone to limit consumption on cold winter nights; there are no time-based incentive rates in our area.
If the car were plugged in using the Level 1 charger (which plugs into a typical 120 V outlet), then the power draw would be about 1200 W, with the charge time (hours per km of range) multiplied accordingly. That’s like an area heater or a hair blower, but running continuously for maybe 12 hours.
The same reasoning applies to our Chevy Volt, but with a much smaller battery and an internal charger that limits Level 2 at about 4000 W.
To wind back to the OP a bit.
With electrical power generation the word “grid” is used, so much so that it is almost one word. The power generation grid. You have producers of electrical power, and users, and there are more than one of each sort. This is important. You connect a power generator to the grid, and power goes in, and consumers connect to the grid, and pull power out. If there is more than one generator, it makes no sense to try to talk about which generator your power came from. Electrical energy is a commodity.
Like a tug of war, the two sides must balance. If there is too high a demand, it pulls down the grid, and generation literally slows. The spinning generators will slow down. Same if there is too much power being pushed in - the generators will speed up. Neither is good. Either will result is damage, and the system will operate to avoid damage. In the extreme this can mean disconnecting everything from the grid resulting in a power outage.
So there are constraints placed on the system, constraints which are a measure of its stability. The frequency the generators spin at is a very good proxy of supply and demand, and the most important constraint on the grid is how stable that frequency is. The metric is how much the frequency changes per unit time (in the accursed units of Hertz per second.)
In traditional power generation systems very short term changes in load can be ridden out simply because the generators consist of very large rotating machines with lots of mass, and thus inertia. So much so that the usual term for provided stability is “inertia”.
Enter green and renewable energy sources. In many markets, if there are green suppliers, you can buy your electricity from those generators. It comes through the same wires as the evil coal bring power. But if you buy the energy, and they generate energy, the books are expected to balance. They had better have put enough energy into the grid to match the energy you drew from the grid. So, in this sense you can charge your car on green power. Even if your next door neighbour drives a gas guzzling truck and buys his electricity from the coal burners.
Things like wind and solar don’t have inherent inertia. This makes for an interesting question. How do you get stability in a grid powered by more and more renewables? Stability is itself a commodity. If you can provide grid stability you can sell that stability. We are seeing a real market for big batteries that can provide grid stability, and they can both undercut the traditional suppliers and make real money doing so.
So, in a grid like this, when you plug your car into the mains to charge it, the sudden spike in demand may be met for a few seconds by a battery. Similarly, when you unplug your car, the sudden drop in demand may be made up by the same battery charging itself. Longer term changes in demand are addressed with longer acting mechanisms. Different more traditional power generating systems have different lag times in changing, with things like nuclear power being slowest, followed by coal and other traditional steam turbine systems, with things like gas turbine and hydro-electric systems being much faster.
Going forward, more modern wind and solar generating farms are being built with the capability to provide inertia. This requires some changes to the way the grid operates and how the operating frequency is set. Such devolvement of stability and short term power generation has reached the point where domestic batteries (ie Tesla Powerwall) can participate in the market. Where I am you can get a subsidy from a wholesale market player to install a battery if you let them use it as part of their stability product.
Define “large scale”.
The video says that one company is doing 60 tons per day. Granted it is nowhere near enough now but, also, they are not the only company doing it.
The point is, the effort is there.
Lithium recycling has the usual very simple metric. Is it cheaper to get lithium out of old batteries or out of the ground? As a potential lithium bearing deposit batteries lose out badly to natural sources. There is remarkably little in a single battery.
If old lithium batteries were all dumped into a dedicated landfill, once it became economical we could simply mine it again. It won’t be going anywhere.
Companies are talking about extracting lithium from the Salton Sea. I think the ‘high altitude’ part is because the playas are there to begin with.
If you watch the video I posted above they claim they are doing it profitably but I grant that can be a dodgy term.
Also, they are getting a lot more than lithium out of the recycling process that they can sell. IIRC they say they get 90% of the battery back to re-sell.
Sorry, it was 2 AM and I forgot to make my point.
There are 31 houses on our street, and there are 2 Tesla EVs, a Ford Mustang Mach-E EV, 2 Chevy Bolts EVs, a Chevy Volt PHEV, a Mitsubishi PHEV, a Ford C-Max PHEV and possibly also a Ford Escape PHEV. The infrastructure hasn’t been upgraded to support this, we have flat kWh rates that don’t encourage people to delay charging, so presumably all these cars are plugged in at 6 PM while everyone is cooking dinner, and it works just fine. Of course, in Québec, most homes are heated electrically, so the transformers etc. were probably heftier than in Texas to begin with.
Recycling of plastics is a genius marketing myth begun and perpetuated by Big Oil. Hopefully this won’t happen with Lithium batteries.
/endhijack
Thank you for posting what a charge looks like. 7000 W at 240 is 30 amps. That is a good size AC unit or just a little more that what an electric would draw. If your neighborhood the lights go dim when everyone is running their AC then the addition of EV could be a problem. But if on a hot day everyone can run their AC and dryers then there should be not problem.
I don’t know anything about that but I do occasionally get things forwarded to me, like the OP, from my conservative friends railing about how electric cars use more energy, not less.
I just assumed they are all an attempt to keep people using fossil fuels.
I believe FB posts like these are politically driven and are not genuine.
Here’s an example post one of my FB ‘friends’ passed along.
“ An interesting take on Electric Cars from a conversation:
“As an engineer I love electric vehicle technology However, I have been troubled by the fact that the electrical energy to keep the batteries charged has to come from the grid, and that means more power generation and a huge increase in the distribution infrastructure. Whether generated from coal, gas, oil, wind or sun, installed generation capacity is limited.
IF ELECTRIC CARS DO NOT USE GASOLINE, THEY WILL NOT BE PAYING A GASOLINE TAX ON EVERY GALLON SOLD FOR AUTOMOBILES, WHICH WAS ENACTED TO MAINTAIN OUR ROADS AND BRIDGES. THEY WILL USE THE ROADS, BUT WILL NOT PAY FOR THEIR MAINTENANCE!
In case you were thinking of buying hybrid or an electric car…
Ever since the advent of electric cars, the REAL cost per mile of those things has never been discussed. All you ever heard was the mpg in terms of gasoline, with nary a mention of the cost of electricity to run it.
Electricity has to be one of the least efficient ways to power things, yet they’re being shoved down our throats. Glad somebody finally put engineering and math to paper.
If you really intend to adopt electric vehicles, you will face certain realities. For example, a home charging system for a Tesla requires 75 amp service. The average house is equipped with 100 amp service. On a small street (approximately 25 homes), the electrical infrastructure would be unable to carry more than three houses with a single Tesla each. For even half the homes to have electric vehicles, the system would be wildly over-loaded.
This is the elephant in the room with electric vehicles. Our residential infrastructure cannot bear the load. So, as our genius elected officials promote this nonsense, not only are we being urged to buy these things and replace our reliable, cheap generating systems with expensive new windmills and solar cells, but we will also have to renovate our entire delivery system! This later “investment” will not be revealed until we’re so far down this dead end road that it will be presented with an ‘OOPS…!’ and a shrug.
If you want to argue with a green person over cars that are eco-friendly, just read the following. Note: If you ARE a green person, read it anyway. It’s enlightening.
Eric test drove the Chevy Volt at the invitation of General Motors and he writes, “For four days in a row, the fully charged battery lasted only 25 miles before the Volt switched to the reserve gasoline engine.” Eric calculated the car got 30 mpg including the 25 miles it ran on the battery. So, the range including the 9-gallon gas tank and the 16 kwh battery is approximately 270 miles.
It will take you 4.5 hours to drive 270 miles at 60 mph. Then add 10 hours to charge the battery and you have a total trip time of 14.5 hours. In a typical road trip your average speed (including charging time) would be 20 mph.
According to General Motors, the Volt battery holds 16 kwh of electricity. It takes a full 10 hours to charge a drained battery. The cost for the electricity to charge the Volt is never mentioned, so I looked up what I pay for electricity.
I pay approximately (it varies with amount used and the seasons) $1.16 per kwh. 16 kwh x $1.16 per kwh = $18.56 to charge the battery. $18.56 per charge divided by 25 miles = $0.74 per mile to operate the Volt using the battery. Compare this to a similar size car with a gasoline engine that gets only 32 mpg. $3.19 per gallon divided by 32 Mpg = $0.10 per mile.
The gasoline powered car costs about $25,000 while the Volt costs $46,000 plus. So the Canadian Government wants loyal Canadians not to do the math, but simply pay twice as much for a car, that costs more than seven times as much to run, and takes three times longer to drive across the country.
WAKE UP NORTH AMERICA!!!”
Any screed that ends with this appeal to patriotism must be believed without question regardless of the substance of the claims. Quod erat demonstrandum, no argument can be made, ecce homo, ergo elk.
Stranger
The first-generation Volt had a 16 kWh battery, good for about 65 km (40 miles) on battery unless you drove it like a race car. The second-generation Volt had a bit more electric range, maybe 75 km (45 miles); I drive like a monk and can get 100 km in summer. The Volt, of course, would take the exact same time as a gasoline-powered car to drive across Canada since you’d be using the gasoline engine for that. I paid 41000$ (Canadian) for my second-generation Volt in 2017, before subsidies.
I pay about 10 cents (Canadian) per kWh, a litre of gasoline in this area is about 2.15$ (Canadian) right now. All in all, for us, the energy cost per km for an electric car is about 1/7th of the energy cost per km for a similar gasoline car. Before the crazy fuel prices, the ratio was closer to 1/5.
Outside Québec, electricity is more expensive and fuel is cheaper, so the ratio would be less favorable. But where in North America does somebody pay 1.16$ per kWh ? And how can a text supposedly written by a Canadian indicate fuel prices in dollars per gallon ? What kind of gallon, and what kind of dollar ?
\rm{Watts} = \rm{Volts} \times \rm{Amps}
So you can get more watts by increasing amperage, increasing voltage, or increasing both.
Increasing amperage requires using thicker wires, which are able to carry more current. Increasing voltage is often much easier, because the same wire may be able to carry 110 or 220 volts, but limited to 20 amps, for example. So, for high power applications, like ovens, it is easier to increase the voltage.
So to get 11000 watts, you’ll need either 50 amps at 220 volts or 100 amps at 110 volts. 50 amps requires 6 gauge wire, and 100 amps requires 4 gauge wire. The wire is thicker as the numbers get smaller. 6 gauge residential wire is about $6/foot, and 4 gauge wire is about $10/foot. There are other reasons to prefer lower amperage aside from just materials cost.
That is important for EVs, because you want to be able to charge quickly enough to fill the car overnight. Most people don’t need to go from 5% to 90% charge every night, but being able to go from 40% to 90% in less than 10 hours is convenient.
Even with the low numbers of electric cars, utilities are already thinking about ways of spreading out the charging to avoid overloading the grid. For example, my utility pays me to let them decide when my car charges.
I plug in the car, and the utility lets it charge for 5-15 minutes, to get a measure of how quickly it will charge (why can’t they just remember this from last time?). Then they use my current state of charge, my desired ending state of charge, and when I’ve told them I want the car to be charged (7 am, for example), to decide when the car should charge.
So I can plug in at 6pm, the utility does their measurements, calculates I’ll need 5.5 hours of charging that night, and then might tell the car to start charging at 8pm, 1am, or whenever they think is best.
I can always override the whole thing, but just telling the car to charge now.
This is all done with no additional equipment (other than my existing charger). I just have to give the utility a code to access Tesla’s API to control charging on my car. Revoking access is as easy as changing my Tesla password.
One idea is to use the batteries in plugged-in electric vehicles to meet demand at peak periods, when bringing another generating plant online would be expensive or perhaps not even possible. Obviously, the car owners would need to sign onto such a plan, which perhaps might only draw down a small percentage of the car’s total charge. And maybe those who volunteer for this might get a discount on their electric rate.
The EVs-will-break-the-grid and EVs-will-damage-the-environment arguments…these are surely jaded and old by now. The whole auto industry is surely moving to an electric drive chain. The grid can be adapted to work with EVs. The boat has sailed!
Maybe it is the pickup truck drivers growing impatient for the EV versions to come onto the market at a price they find reasonable? It takes time for an industry to cover all markets. The EV business still has a long way to go.
Some customers do not like change and some companies have their head in the sand. Eventually they will read the writing on the wall.
It’s not just pickup truck buyers waiting for vehicles at a reasonable price. My car is a 2010 Honda Fit that I bought for about $20,000 in 2010. I think even with federal and state tax breaks, even the cheapest EV might cost $10,000 more.
There are a lot of anti-EV talking points knocking around, and it’s hard to address them all.
I just want to focus on this specific question which is interesting:
- When my air conditioner turns on, does someone at the power plant have to throw another lump of coal in the boiler?
The answer is (kind of) yes. Here’s how it works (imagine for simplicity there is only one generator on the system):
Start with the system in balance - the same amount of power being generated as is being used (including losses).
You turn on an appliance, increasing the load on the system. The immediate effect is that the system frequency and voltage will drop.
The governor on the steam turbine generator will try to maintain the speed at 3600 rpm by opening the inlet valves and admitting more steam to the turbine. At this point, we don’t have to add more fuel to the boiler yet because there is a lot of energy stored in the form of steam in the boiler drum, and it’s possible to draw down some of this.
As we draw off more steam, the drum level controller will say “Increase the firing rate to maintain a safe level in the drum”. More pulverised coal and air will then be blown through the burners to generate the required amount of steam.
There are lots of other boiler configurations and ways that a system can provide frequency response but ultimately if you use more electricity, more electricity will need to be generated.
Now, in a system with more than one generating unit, it is not the local power station or the average of all the units that is relevant; it is the marginal unit on the system at any given moment. When you plug in your EV, where is that additional kWh generated? It could be for example that your baseload is coal and nuclear but the marginal unit is coming from a gas-fired power station providing operating reserve.
Where I live, the marginal unit at night is often wind power. How can that be - either the wind is blowing or it’s not, right? Well, the explanation is that wind turbine generators are often curtailed off so as not to exceed certain operational constraints. An increase in demand is met in the first instance by increasing wind generation, the marginal cost of which is zero.