Electric Cars Won't Strain the Power Grid 438
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."
Well.. being in that biz (Score:5, Informative)
Electric Cars Won't Strain the Power Grid (Score:1, Informative)
This IEEE article (http://spectrum.ieee.org/green-tech/advanced-cars/speed-bumps-ahead-for-electricvehicle-charging) states a Level 2 EV charger can draw as much as 6.6 kilowatts.
No problem, long as they charge at night (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.
Re:Is this future tense? (Score:5, Informative)
http://en.wikipedia.org/wiki/Rolling_blackout [wikipedia.org]
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 [greencarcongress.com]
Re:No problem, long as they charge at night (Score:1, Informative)
Power is not overproduced at night, otherwise there would be a loss of grid synchronization, uncontrolled voltage rise, or the need for massive load banks.
Power stations which require significant startup or shutdown intervals provide base load, while flywheel, gas turbine, hydroelectric and other generation systems which can respond quickly to changing loads provide for peak consumption.
If there was a rapid shift towards night time power consumption power prices could actually increase in many areas, at least until additional base load power plants could be brought online, due to the additional cost involved in running most peaking plants.
Vehicle to Grid (Score:3, Informative)
Re:No problem, long as they charge at night (Score:5, 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.
Re:Plus they could be set to charge at night (Score:3, Informative)
A constant mid-high usage is basically the best case scenario for a power grid. This is especially true where nuclear power plants and other electricity producers can't actually be scaled back during low-load situations.
Re:What if... (Score:5, Informative)
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.
Re:Plus they could be set to charge at night (Score:5, 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
Re:No problem, long as they charge at night (Score:5, 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.
Re:No problem, long as they charge at night (Score:2, Informative)
I expect the peak load generators to shut down at night and base load generators to shut down as much as they can.
That's what I thought too. But apparently it's too slow (and costly?) to fire them up once/twice each day, so they just keep on running during off peak times. Generation is reduced during off peak times, but not as much as we might like.
/. recently about a type of battery created with enourmous pressure that would be able to store much more energy than current technology batteries. This is where such batteries would be used, while current, cheaper, types of batteries would continue to be in mobiles phones and laptops.
Unfortunately, to prevent brownouts, the peak usage of the day combined with the momentum of starting up generators, limits how much power generation can be reduced during off peak times. This means that, although the difference in consumption may vary alot (ex. http://www.solarchoice.net.au/blog/how-do-i-use-electricity-throughout-the-day-the-load-curve.html [solarchoice.net.au]), power generation cannot vary anywhere near as much. So, during off peak (especially during night time) there is alot of power that currently is not being used.
If we had batteries that could store off peak power, and give it back to us during high peak, then the whole power generation curve could be lowered, and we could save alot of fuel. It has been suggested that electric car batteries may be able to help with this (though I think people would prefer having their cars charged and ready to drive instead). There was a post on
In the meantime, charging electric cars during off peak times won't strain the grid, because much of that power is currently wasted anyway.
Re:No the main problem is (Score:3, Informative)
And then the fact that you have to replace a major and expensive component of your vehicle (batteries) every 3-5 years.
Where are you pulling that figure from?
I doubt the battery lifespan is going to be that short when the Chevy Volt (for example) is coming with a 150,000 miles/10 year warranty, and Nissan seems likely to follow suite with the Leaf.
Re:No problem, long as they charge at night (Score:5, Informative)
Re:No problem, long as they charge at night (Score:5, 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. ;)
Re:No problem, long as they charge at night (Score:5, 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).
Re:What if... (Score:3, Informative)
The biggest heat sources in an electric vehicle are the inverter and the motor. Li-ion pack efficiencies vary a lot depending on the particular chemistry choice and operating conditions. I've seen as low as 94% and well over 99% (some chemistries really are absurdly efficient). There's also some losses in the cabling.
Chargers are not "80-90%" efficient. They're usually 92-93% efficient.
Re:Well.. being in that biz (Score:4, Informative)
Your correct but the environmentalist want every car on the road to be either electric or hybrid, preferably electric. Hmm about 25,000,000 cars registered in CA give or take, so at a 2kwh charging load thats 2,000 & 25,000,000 = 50,000,000,000 or 50 gigawatt hours and that is more then the entire supply that the state of California has available and thats a combination of all available fuels we have on line.
Yeah! And my gasoline car burns about two gallons per hour of driving. Hmm about 25,000,000 cars registered in CA give or take, so 2 gallons per hour times 24 hours * 365.24 = 440 billion gallons of gasoline per year, three times what the whole US consumes!
(I.e., the problem with your calculation is that people's cars don't charge nonstop; they charge intermittently and in a staggered manner, whenever people or a smart grid tells them to. Never will they all be charging at the same time)
The next problem is that gigawatt hours are a measure of energy while 2 kilowatts (not kwh) is a unit of power.
That is the myth if the electric car, if we shift to all electric we simply shift the fuel consumption to another type of engine.
That's the "long tailpipe myth", and it's a myth. All peer-reviewed studies on the subject show that it's much better to switch to electric.
Now an electrical generating plant is more efficient then an internal combustion engine but you have to build out that capacity and keep a lot of it on hot stand-by because it takes a long time to spin up from cold to generating electricity
Wrong; utilities love EVs because the stabilize and even-out the load, meaning *less* need for peaking and spinning reserve.
Additionally no one is really talking about the insanely toxic batteries that will have to be disposed of on a regular basis.
You clearly have no clue what you're talking about. You can literally, legally throw discharged A123 batteries into municipal trash. The CEO of BYD likes to show off by *drinking* his batteries' electrolyte. As for "regular basis", we're talking ~80% capacity in 10 years.
Technology can move fast but we are pushing the limits of known technology as far as electrical storage is concerned
Not even *close*. I could list about a dozen cathode techs and two dozen anode techs, each of which could increase the density of their respective electrode ~50% to ~1000%. Will all of them make it to commercialization? Not a chance. Will *none* of them make it to commercialization? Likewise, not a chance. The rate of battery energy density increase has been a pretty steady 8% per year, but it's actually *increasing* of late.
There is a lot of progress being made in Electric double-layer capacitor "EDLC's" but even those are still experimental and cannot provide the kind of power you would need to run say a Tesla car
That's backwards. Capacitors have huge power density but poor energy density.
It depends... (Score:3, Informative)
As usual, the answer is "it depends", with lots of assumptions you can argue about in the absence of actual data.
A biggie is where the grid electricity comes from.
Another is how long the batteries will last, and how long an electric car will last. There have been studies claiming that a Hummer has lower life cycle emissions than an electric car, but they assume an absurdly long lifetime for Hummer and an absurdly short lifetime (and no recycling) for the EV.
Google "life cycle emissions BEV" or something like it and you'll have many hours of reading material on the matter.
Re:No problem, long as they charge at night (Score:1, Informative)
Well, the "hair" you are talking about is called whiskers and is one of the problems you can get when you go with pure tin. (OK, whiskers does not appear on soldered surfaces so you have to remove the oxidated surface area on the pins for this to be a problem.)
Just get 0.1% nickel in the mix and you will not have any of those problems. In fact, whiskers are almost unheard of in EU.
What is Your Problem? (Score:2, Informative)
I don't think he needs to look up "spinning reserve", he has (almost) described it.
Nuclear and the most efficient other power stations provide the base load. Other stations provide spinning reserve where their alternators are syncronised to the grid, turning at grid frequency but with little or no power input. The boilers of spinning reserve fossil fired stations are kept hot but with little energy flow. There is not much wasted energy - despite some crazy theories here about dumping electricity to resistor banks and even light bulbs, ffs!!!! Spinning reserve stations can be brought on-line in minutes.
Other stations are shut down but at standby, with levels of notice required to join the grid typically hours (but days for a nuclear). Hydro stations however can start and stop generating like at the turn of a tap.
The GP's last paragraph was perfectly logical. Currently electricity is sold cheap at night (to local distributors, factories, railways and some end consumers) because of the otherwise wasted capital and attendance costs of the spinning reserve, not because much fuel is being wasted. However if there were greater demand for night electricity, the price of night electricty (and I believe the GP meant night electricity) would go up with market forces.
Like the grocer might sell stale bread cheaper than fresh. But if there were suddenly a big demand for stale bread, because someone had invented a gadget to restore it, he would put its price up (even if not as much as fresh bread) believe me.
I am a (nuclear) power station engineer btw.
Re:No problem, long as they charge at night (Score:5, 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/ [nytimes.com]
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.
I know it's a joke, but... (Score:3, Informative)
I did some analysis on this... (Score:3, Informative)
...and the situation seemed more worrisome than this article suggests. I assumed that, eventually, people will shift to all-electric vehicles as opposed to hybrids. Below are the numbers I used. Did I flub the math? Because these calculations sure seem to suggest an electricity crunch as we move off petroleum:
Total miles driven in the U.S. yearly: 3x10^12 mi
http://www.greencarcongress.com/2008/05/us-vehicle-mile.html
Electricity use per mile for a fully electric car: 0.17 to 0.37 kWh/mi (mean: 0.27)
http://en.wikipedia.org/wiki/Electric_car#Energy_efficiency
Total electricity needed to support all miles driven by fully-electric vehicles: 3x10^12 mi * 0.27 kWh/mi = 8.1x10^11 kWh
Total yearly electricity production of the U.S. (2007): 4.157x10^9 kWh
http://en.wikipedia.org/wiki/Electricity_sector_of_the_United_States#Electricity_generation
In other words, if we assume that hybrid/electric vehicles currently account for an insignificant portion of total miles driven, and we were to covert all vehicles to be fully electric, U.S. electricity production would have to increase by a factor of 194 in order to support the additional load.