How does a power plant work? (Question is related to electric vehicles)

One of my Facebook friends is dead-set against electric vehicles (EVs), at least as they currently (ha!) exist. Yesterday, he posted a cartoon that shows a Tesla plugged into a coal-burning generator. The point of the cartoon is that, since most electricity in the USA is generated in coal-fired power plants, EV owners are powering their cars, not with dirty gasoline, but with dirty coal.

So, how true is this?

There is a very large coal-fired power plant in my town, owned in part by the City of Austin. I buy electricity from my city, which in turn buys electricity from the other entity (the Lower Colorado River Authority, or LCRA) that owns the giant power plant. LCRA generates electricity through natural gas, hydro-electric dams, and coal. So, is it fair to say that the computer I am using right now powered by coal?

  • My impression is that a power plant pretty much generates whatever it generates, regardless of who is using the electricity. I mean that it is sort of like the water in the lake – whatever water is there is all the water there is, regardless of how many people are drinking at any particular time. Is that at all accurate?

  • When my air conditioner turns on, does someone at the power plant have to throw another lump of coal in the boiler?

  • What impact does at home EV charging have on a homeowner’s electric bill?

  • What would happen if half of the households in my town of ~5000 people had plug-in EVs? Would the power plant (or city utility) be able to deal with that? What about the distribution infrastructure? One person in the Facebook discussion said that she read that most towns can only tolerate one or two EVs in a neighborhood block before problems would arise. Is there any truth to that?

  • This idea that EVs only transfer the carbon emissions from the car’s tailpipe to the stacks at the power plant. Given that the local power plant really does burn coal, is there any truth to that? Is there any benefit to having the emissions at the power plant rather than the tailpipe of a car?

  • I think I understand amp and watt, but how does a volt figure into any of this?

This has been done to death.
The simple answer is: the powertrain efficiency of an EV, and the efficiency of large power plants make EVs “greener” than ICVs, even if the power comes from coal.

ETA: Yes, when you turn on you A/C, the power plant has to throw another lump of coal on the fire. The fact that there are millions of individual loads the average out makes this manageable. But, that’s why power companies charge much less for off-peak generation (which is when EVs are generally charged).

Not really. The amount of power being generated does have to match usage. One Tesla won’t make any measurable difference, but if the grid is consuming X megawatts, X megwatts must be produced.

When you turn your AC on that doesn’t make enough difference to matter, exactly. But then, individually, NONE of us matter, but collectively we clearly do.

Depending on where you live, a Tesla will cost you maybe five bucks to charge at home. In places with higher costs of electricity, it’ll be a few bucks more.

No. A Tesla doesn’t need a lot of electricity at once; you can charge it off a normal circuit. A specialized charger, if you get one installed, takes about as much power as a clothes dryer. Your grid wouldn’t collapse if two more people on your block used their dryers.

Maybe this link is of interest:
It currently indicates about 5 GW of extra capacity, in case everybody in Texas suddenly started to plug stuff in.

Interestingly we see high demand spikes happen all the time. In Great Britain there is a TV in powerplant control rooms. They watch sports games and, when a period or game is about to end they ramp-up power production to meet a spike in demand because so many people go to the kitchen and put the kettle on to make tea. (called TV Pickup)

The power plants are not running at 100% output all the time. They can increase and decrease power as needed. If an extra load comes online then they increase output. If some people plug in an EV it will come nowhere near stressing the power delivery system.

If everyone in (say) Dallas bought an EV at the same time and plugged them in at the same time then there would be problems. But that won’t happen.

Not true and has not been true since 2009:

Even if it were true that most electricity is produced by coal, point of an battery electric vehicle (BEV) is that the source of electrical power is fungible; it can switch between coal, gas, nuclear, solar, wind, and hydropower seamlessly. There are other criticisms about electrical vehicles, such as the capacity to produce batteries, the robustness of the current power grid to support an electrified transportation infrastructure, and the fiscal problem of replacing gasoline- and diesel-powered vehicles with sufficient speed to make an impact upon climate change and petroleum dependence even assuming that we can manufacture the vehicles that quickly, but the idea that BEVs will produce the same or worse emissions because the power is generated predominately by burning coal is not remotely correct.


Funny of all the places you could be and ask this question, you’re in Texas, with its notoriously crappy and isolated grid. In Texas it might actually be possible to bring down the grid with too many EVs. (or A/Cs, or toasters…)

Apparently you can bring down the ERCOT-managed Texas Interconnection grid with what would be considered a mild cold snap in Minnesota.


Agree with the above positive points about EVs, but also want to point out two negatives :

  1. Batteries used in EVs or Hybrids are claimed to be “recyclable” but they have not been recycled at all. They get repurposed at the best but true recycling does not happen.

  2. For some reason unknown to me, most of the world’s lithium is extracted from a mineral-rich brine underneath the briny lakes of high-altitude salt flats. Lithium mining consumes a LOT of water and these places usually do not have much fresh water. So, mining is beginning in Nevada and Utah and a lot of river water will be diverted to this operation in an area which is already stressed for water. The same story is playing out in South America too.

The former CTO of Tesla is working on this problem. They are already doing some recycling (small industrial scale). There is a long way to go yet but clearly people are thinking and working on it.

Yeap they are working for more than 20 years almost , but its a well kept secret unless you ask. When we bought our tesla and our Hybrid cars, we were told Lithium batteries are recyclable. They left out that they are actually not recycled.

The lithium found in playas or salars is a chloride salt that is mixed with a lot of potassium and magnesium chlorides and other salts like boron compounds. The lithium chloride first needs to be separated from other contaminants and then reacted with lime to form a precipitate of lithium carbonate, all of which requires it to be in a dilute aqueous solution. This requires a lot of water, and it has to be fresh and mostly mineral-free water. The residual can and should be reclaimed and reused but there are limits to how much can be practically filtered. The process also produces a lot of residual waste that is typically disposed in open pits or just dumped in mounds where it dries and becomes a toxic alkaline dust.

Lithium can be extracted from clay, pyroxene minerals, or even seawater, but at much greater energy cost and effort per yielded mass. Frankly, the main tentpole in current plans for broad electrification of ground transportation is the lithium batteries; specifically refined lithium for processing into electrode material and the cleanroom mass production facilities to produce the electrolyte and package into a battery. Lithium-ion and lithium-polymer batteries are pretty close to the maximum theoretical energy density and we really need to develop a higher energy density battery that is also easier to recycle. (It is theoretically possible to reclaim lithium from Li-ion and LiPo batteries but nobody does it because it is vastly cheaper to mine it.)

Electrification for ground transportation is a necessary but not trivial step, and it does have its own environmental impacts that have to be considered and remediated. Still, those problems are far more technically feasible than the fantasy of wide-scale atmospheric carbon capture and sequestration.


Watch the video above. They are recycling batteries. Right now. In an industrial facility (so, not just two guys in a lab showing it can be done).

They certainly cannot handle all of the batteries out there (not close) but their goal is to work towards that. (although I would be surprised if they were the only ones out there trying this)

It is clear it can be done. As always, the question is can it be done profitably. As the cost of batteries skyrockets (for various reasons) it makes the case for recycling that much more attractive.

@Stranger_On_A_Train thank you for explaining the extraction part. Would you know the reasons why Lithium accumulates in such flats at high altitudes ?

Not challenging that it cannot be done. @Whack-a-Mole all I am saying is that it is not being done and it has been more than 20 years since Lithium batteries were widely adopted. And I still do not see Lithium recycling happening at a large scale in the next 10 years.

Same with plastics - people put them in recycling bins but they are mostly sent to the landfill with other garbage.

There’s a lot of greenwashing that happens and there are tradeoffs with every technology.

Here in Illinois our EVs our nuclear powered.

(OK, about 1/2 nuclear powered)

They occur in salt pans or dry lakes where the climate has become so arid that the water has almost completely evaporated and the seasonal rains saturate into the ground periodically but then evaporate away. This causes migration and stratification of the different minerals so that you get highly concentrated layers. Lithium has a 0.002% abundance in the crust so it is in about the same abundance as so-called ‘rare earth’ minerals and is difficult to find in concentrations that make it financially viable for extraction except these features.


Remember, “recycle” is only the third of the three Rs. If you have an old battery, and you can still re-use it as a battery, there’s no reason you would want to recycle.

As to power plants and individual loads like a light, AC unit, or kettle turning on: In the very short term, every time someone adds a load, the power grid’s voltage and frequency are both pulled down slightly, and every time something is turned off, the voltage and frequency increases slightly. But both changes are only very slight, because any one appliance is only a very small fraction of the whole load (a grid serves basically half of North America). And everything that’s on the grid can handle some level of fluctuation. They just have to keep things steady to within some level of tolerance, and they can mostly do that by recognizing broad patterns, without needing to worry about the details: Patterns like the time of day, and the day of the week, and so over those sorts of timescales, they turn some of the generators on or off, or run them hotter or cooler, or probably a few other ways of adjusting things.

And because most electric-car charging would be done overnight, when most other loads are relatively low, we could handle an awful lot of electric cars without adding any more capacity to the grid. Even if the grid is strained at peak power, during the day when everyone has everything turned on, it still has surplus capacity at night. There are still plenty of reasons to want to upgrade the infrastructure, and we’ll need to eventually, but electric cars aren’t the main factor behind that need.

Except most rechargeable batteries have a finite cycles of charging/use after which they become practically useless.

With lithium ion and lithium polymer batteries they grow defects as the age that result in resistive heating, and eventually become unstable and can autoignite. This limits the reusability of such batteries even in fixed installations where mass energy capacity. This is why lithium ion phosphate (LiFePo4) batteries or deep cycle lead acid are typically used in off-grid solar storage.