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Electric Cars Won't Strain the Power Grid

thecarchik writes "Last week's heat wave prompted another eruption of that perennial question: Won't electric cars that recharge from grid power overload the nation's electricity system? The short answer is no. A comprehensive and wide-ranging two-volume study from 2007, Environmental Assessment of Plug-In Hybrid Vehicles, looked at the impact of plug-in vehicles on the US electrical grid. It also analyzed the 'wells-to-wheels' carbon emissions of plug-ins versus gasoline cars. The load of one plug-in recharging (about 2 kilowatts) is roughly the same as that of four or five plasma television sets. Plasma TVs hardly brought worries about grid crashes."

26 of 438 comments (clear)

  1. What if... by Mitchell314 · · Score: 5, Funny

    ...most people buy electric SUV's? Didn't think that one through, did they? :P

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    1. Re:What if... by JordanL · · Score: 4, Interesting

      You were being funny, but I think it's important to point out: we produce about 14 exajoules of energy for electric power a year. We use about 28 exajoules for transportation.

      This study seemed to overlook something rather important.

    2. Re:What if... by rsborg · · Score: 4, Informative

      You were being funny, but I think it's important to point out: we produce about 14 exajoules of energy for electric power a year. We use about 28 exajoules for transportation.

      This study seemed to overlook something rather important.

      No, I think the study's numbers are on-base. Electric car adoption will not be 100% overnight (or we'd be pretty screwed). They are assuming 500K (out of 300M) cars with current power plant base loads... and that would be 0.0017, about 1/6 of one percent. I think our nighttime base load (which throws away energy right now) can handle it.

      And that's assuming you are calculating actual energy converted from gasoline (a horrible conversion loss) and you are not conflating industrial/commercial transport with personal transport.

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  2. Well.. being in that biz by gearloos · · Score: 4, Informative

    Being in that particular biz, I can say I am not concerned about it. Most of our power goes to industrial loads anyway. Joe Consumer is only a real concern to us on those hot mid July afternoons when he is at work running his air conditioner at the same time as the thirty million others Joes. Now, if they were to ALL buy electric vehicles and charge them in the afternoon in the middle of the summer while at work.. hah well, I think the major load on the charging systems would either be early morning when you just get to work and plug in, or early evening when you just get home and plug in. Not exactly prime time for brown outs..

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    1. Re:Well.. being in that biz by RealGrouchy · · Score: 4, Insightful

      I think the major load on the charging systems would either be early morning when you just get to work and plug in, or early evening when you just get home and plug in. Not exactly prime time for brown outs..

      My understanding, based on the time-of-use billing coming soon to a power company near me, is that early evening when you just get home and plug in is exactly prime time for power shortages.

      You could centrally control when recharging stations activate, but is somebody plugging in at 5:30 pm because they want to recharge it overnight, or because they want to pick up their kids from (band/soccer/whatever) practise at 9pm?

      - RG>

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  3. This sort of thing can only be good for wind/solar by Entropius · · Score: 5, Interesting

    The more uses of electricity we have that can be done "whenever", the better the future looks for power sources like wind and solar. Hopefully power companies will start charging different rates for on-peak and off-peak residential usage (like they already do for major industrial users), and the market will take care of it.

  4. Sure.. by Mr0bvious · · Score: 5, Insightful

    Yes but plasma TVs replaced CRT TVs.

    And I expect there was a rather large switch from incandescent to compact fluorescent globes around the same time - which may have given greater savings than losses from those plasmas....

    But what on earth kind of argument is that? Electric cars wont be a problem coz plasma TVs weren't.... How absurd.

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  5. No problem, long as they charge at night by Geoffrey.landis · · Score: 5, Informative

    If the electric cars go home and charge at night, no, they won't strain the grid. Power is overproduced at night (you actually can't spin down the generators all the way, so they produce power even if nobody wants it.)
    If they decide to charge during the day (for example, if people charge them at work), it could strain the grid. Particularly if they charge during hot summer afternoons.
    Unless a significant part of the grid goes to solar, which produces the highest power during the daytime at summer, of course.

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    1. Re:No problem, long as they charge at night by hairyfeet · · Score: 5, Insightful

      I think the bigger question, which I didn't see answered in TFA, is whether these things are truly better than ICE vehicles on the environment. I mean sure we know they'll probably be better than a Hummer, but has anyone figured out what the mining of lithium for the batteries, the toxic components used in such batteries, the amount of carbon put out in production, the amount used by the grid (many places still have coal plants you know) and finally the disposal and replacement of those batteries after 3-5 years, how all of that compares say to a Kia or other small 4 cyl ICE vehicle?

      Because as we saw with the "get rid of teh evil lead solder!" stupidity we can often make things worse instead of better by not thinking things through. in the case of solder we ended up with a lot more e-waste because the crap solder they replaced lead with broke down much faster than the old, and thrown into a burn pit in China frankly isn't any better than the old. So I would like to see what a "birth to death" study of elec VS ICE would show before I say that elec is the way to go. After all it won't be doing us much good if we just trade carbon at the tailpipe for carbon at the plant PLUS piles of dead batteries PLUS lots of waste in mining and disposal. We need to look at the entire cycle before judging one tech or another.

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    2. Re:No problem, long as they charge at night by TooMuchToDo · · Score: 4, Informative

      Is there a dummy load set up somewhere?

      Sort of. What happens is the power company almost gives away the power between midnight and 5am to industrial customers and large cities with *lots* of street lights. Nuclear power plants in particular run extremely poorly at anything under 90% of what they're rated to run at, whereas natural gas generators, hydro, etc can be scaled forward and back.

    3. Re:No problem, long as they charge at night by digitalunity · · Score: 4, Interesting

      That's a good point. I'm curious to know also if the battery production was taken into account when they decided electric vehicles would be better.

      Surely from a pure power plant versus tailpipe emissions, the power plant won out. They scale better than auto gas engines do.

      I'm still on the fence about lead. I'm glad it's gone from a lot of industrial and consumer products, but at the same time it did serve a valuable purpose. And when it comes to batteries, lead-acid batteries are dead simple to recycle. Lithium on the other hand isn't.

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    4. Re:No problem, long as they charge at night by digitalunity · · Score: 4, Informative

      Not sure if you know why, but the European Union passed a Restriction on Hazardous Substances law which limits among other things lead in all products sold in the EU. Sadly. the market in the EU is so large that many manufacturers simply changed over all their production lines to use lead-free solder and other products.

      What I've heard that with lead-free solder is that it will eventually grow hair like structures between wave soldered IC pins that are closely spaced and they aren't protected with conformal coatings. This causes malfunctions in equipment. Lead prevented that from happening but it was decided, for whatever reason, that being lead-free was better for the environment than the waste the changeover created.

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    5. Re:No problem, long as they charge at night by afidel · · Score: 4, Informative

      They also often have to scale down during the hottest times of the year due to problems with thermal pollution of their heat sinks (rivers or lakes).

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    6. Re:No problem, long as they charge at night by Rei · · Score: 4, Informative

      To put that another way, a 100m rise with a reservoir that's 50m by 50m by 10m stores 5 MWh, enough to run 200,000 houses for an entire day.

      Is this supposed to be problematic?

      Want to see a TON of storage? Run the numbers on pumping a couple meters of water back and forth between Lake Superior and Lakes Michigan/Huron. ;)

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    7. Re:No problem, long as they charge at night by nbahi15 · · Score: 5, Insightful

      Removing lead is progress and in time the restriction will become a non-issue for even those that believe in the goodness of lead.

      In the US, people spent ages bellyaching about the low-flush toilets. Initially the toilets that came out often did perform poorly because when you could use half a lake to flush the toilet you didn't need good design. Designs have improved and one of the greatest wasters of fresh water was reduced.

      Realize that government is a process and that there are always trade-offs. Usually they aren't even entirely clear trade-offs.

    8. Re:No problem, long as they charge at night by Rei · · Score: 5, Interesting

      Actually... I'll go ahead and do the math. Surface areas:

      Superior: 82,400 km^3
      Michigan-Huron: 59,600 + 58,000 km^3 = 117,600 km^3

      So, if we want to cap off a maximum change of a mere 0.5 meter of height, and assuming that such a small amount has basically no affect on the surface area, that's 41.2 cubic kilometers. There's 4 meters height difference between the lakes; let's assume we average maintaining that difference. That would store about 350 GWh after losses -- more than the total generation of all hydroelectricity in the United States for an entire year.

      But want an even crazier one? The Panama Canal is a (proportionally) thin canal that goes over the terrain via locks. But imagine if you had pipes connecting Atlantic to Pacific. It just so happens that the western and eastern coasts of Panama have opposite tides, and the magnitude of the tides is *far* greater on the Pacific tide -- averaging about 3 meters (the Atlantic side averages under half a meter). So you have basically limitless (oscillating) tidal power available.

      IF you can harvest it.... ;)

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    9. Re:No problem, long as they charge at night by Rei · · Score: 4, Informative

      And the latest NG plants are now up to 60%, NOT counting that you can reuse the waste heat for industrial heating. 60% just for the electricity generation.

      The grid is ~93% efficient, chargers ~92-93% efficient, li-ions 94% (inefficient rapid charging) to over 99% (efficient slow charging) in efficiency, and the drivetrain averages 85-90% efficiency in normal usage.

      Non-hybrid gasoline ICEs average about 20% efficiency since the engine runs out of its optimal operating envelope most of the time and much energy is wasted through braking. Diesels average about 25% (their mileage numbers look even better, but part of that is due to the greater density of diesel fuel). Gasoline hybrids can get 30-35% efficiency (diesel hybrids even more, but the added weight and complexity is rarely considered justified by manufacturers).

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    10. Re:No problem, long as they charge at night by ultranova · · Score: 4, Interesting

      So you have basically limitless (oscillating) tidal power available.

      You have limitless tidal power available at any coast: simply dig a reservoir (a bay connected to the ocean through a small channel) and harvest the energy as water flows in and out. You also get a massive swimming pool/dozen kilometers of beachfront property out of the deal.

      Digging those reservoirs would be a useful, unskilled, and labour-intensive project. We have a massive pool of people needing jobs. Hint, hint.

      --

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    11. Re:No problem, long as they charge at night by Gates82 · · Score: 4, Interesting

      I am an engineering for a large utility in the US, granted Civil not Electrical, but the principal for generation is:

      You produce a little spare power that is grounded to handle increases (your buffer)
      There are voltage regulators and capacitor banks at substations to handle small variations in load
      Utilize peaking stations when the load on the grid is particularly high
      The key for generation: RPM of the turbine, as load on the grid decreases it take less energy to maintain the speed of the turbine; so while a turbine may still be spinning at the same speed during high and low demand it is certainly not consuming as much fuel

      With that being said, there is certainly a lag between the consumption of fuel and the utilization of that energy (steam to mechanical motion) that may produce a delay of an hour as load decreases. Utility companies have a great deal of data and they can generally predict when usage will change and adjust the fuel consumption accordingly.

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    12. Re:No problem, long as they charge at night by QuantumPion · · Score: 4, Informative

      Sometimes you end up having to scale your nuclear plant back because there's so much renewable energy:

      http://green.blogs.nytimes.com/2010/07/07/sudden-surplus-calls-for-quick-thinking/

      Columbia is accustomed to reducing power to 85 percent and sometimes 60 percent. In the following days, however, BPA asked the nuclear [note: I added "nuclear" for context] plant operators to go down to just 22 percent. “This year was extraordinary because it all came so heavy and so fast,’’ Mr. Milstein said.

      Here by renewable energy, you mean hydroelectricity. And they had an excess due to larger than normal amount of rain. And the reason why they had an excess of electricity was because they lacked the transmission capacity to sell the power to other areas where it was needed.

  6. How Many Plasma TVs? by BBCWatcher · · Score: 4, Insightful

    The load of one plug-in recharging (about 2 kilowatts) is roughly the same as that of four or five plasma television sets. Plasma TVs hardly brought worries about grid crashes.

    Probably because households buying plasma televisions purchase one, maybe two, and they are replacing cathode tube (with shadow mask) televisions which have been consuming electric load since the 1950s. And those plasma TVs are not operating for too many hours (hopefully), never mind that LCD televisions are far more popular. It's not surprising that many people are at least more concerned when typical two-car households each might add the equivalent of 8 to 10 plasma televisions of net new electricity consumption to the grid. Thankfully that consumption should be off-peak, especially if timed chargers and peak electricity pricing are mandated, but the plasma TV analogy breaks down very quickly.

  7. Color me skeptical... by Jhon · · Score: 4, Interesting

    The load of one plug-in recharging (about 2 kilowatts) is roughly the same as that of four or five plasma television sets. Plasma TVs hardly brought worries about grid crashes."

    I think there are roughly 2 houses on my block (of about 20 homes) that have a single plasma TV. They do, however, have at least a single car. Many of them have 2 or more. That translates as a lot of "plasma TVs" on that block.

    Also, we need to realize that they are limiting their expectations:

    Even if the U.S. alone has half a million plug-ins to recharge (out of 300 million vehicles on the road, remember) within a few years, utility executives aren't losing any sleep. In fact, they're happy. They love the idea of selling you "fuel" for your vehicle.

    Basically they are saying "Electric cars wont bring down the grid -- if they aren't widely adopted". What if, instead of half a million, there's 10-30 million? How many "plasma TVs" does it take to bring down the grid? Add to this that our current administration wants to increase the cost of our energy -- so not only will gas be more expensive, but so will electricity. What's the incentive?

  8. Re:Is this future tense? by copponex · · Score: 5, Informative

    http://en.wikipedia.org/wiki/Rolling_blackout

    Though the term did not enter popular use in the U.S. until the California electricity crisis of the early 2000s, outages had indeed occurred previously. The outages were almost always triggered by unusually hot temperatures during the summer, which causes a surge in demand due to heavy use of air conditioning. However, in 2004, taped conversations of Enron traders became public showing that traders were purposely manipulating the supply of electricity, in order to raise energy prices.

    The DoE has stated that most of the Eastern Seaboard could support the energy requirements of every single car used for commuting today, without any changes to transmission or power production, as long as the cars are charged at night.

    http://www.greencarcongress.com/2006/12/doe_study_offpe.html

  9. Re:This sort of thing can only be good for wind/so by konohitowa · · Score: 4, Funny

    Hopefully power companies will start charging different rates for on-peak and off-peak residential usage...

    What a great idea. And they could market it under a clever name like "time-of-use"or something equally catchy.

  10. Better comparison please by gringer · · Score: 4, Funny

    The load of one plug-in recharging (about 2 kilowatts) is roughly the same as that of four or five plasma television sets.

    Sorry, I don't understand this idea of power rated by plasma TVs. Could you please give that in terms of the number of slow cookers required to have the same draw as one EV charge?

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  11. Re:Plus they could be set to charge at night by cgenman · · Score: 4, Informative

    Tesla range: 160-250 miles (depending on options)
    Subaru G4e range*: 125 miles
    Mini Electric: 100 miles
    Chevy volt: 40 miles
    Coda Sedan: 90 miles
    Nissan Leaf: 100 miles

    *vehicle has not hit production yet