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Charge at night! - 25 TWh of Wind Power Idled in 2010

Posted: Mon Apr 30, 2012 9:49 am
by DaveEV
25 TWh of Wind Power Idled in 2010 in US – Grid Storage Needed
Approximately 25 TWh (yes, 25 terawatt-hours) of wind energy was curtailed (idled) in the U.S. last year to keep the off-peak grid energy price from frequently going negative. That is about equal to the energy in 700 million gallons of gasoline just being thrown away. Curtailed wind energy in the U.S. appears likely to exceed 40 TWh in 2011.
Seems way higher than I'd expect, but it certainly emphasizes that we should be charging during off-peak whenever possible. I know that here in CA minimum grid demand is typically around 3-4 am, though most of my charging tends to occur between 1am-3am.

Makes me wish I could set a charge timer that centered the charge around the middle of the off-peak time period of 12am-5am - so if the car knows it has to charge for 2 hours, it'd charge from 1:30am-3:30am - or if it knew it had to charge for 4 hours it'd charge from 12:30am-4:30am. This would also have the benefit of automatically distributing the start / end times which avoids the spike in demand when the off-peak TOU period starts.

Re: Charge at night! - 25 TWh of Wind Power Idled in 2010

Posted: Mon Apr 30, 2012 10:39 am
by LTLFTcomposite
25 TWh ??

At 4mi/kWh, 12000 annual miles in a leaf will take 3000 kWh.

So that was enough electricity to power 8.3 million Leafs. Check my math.

Re: Charge at night! - 25 TWh of Wind Power Idled in 2010

Posted: Mon Apr 30, 2012 10:49 am
by Reddy
While I agree with "Charge at night!", I have a cannot believe 25 TWh of actual energy was actually "turned off".
From http://www.awea.org/learnabout/industry_stats/index.cfm, there was about 47 GW of total capacity at the end of 2011. At the end of 2010 it was around 40 GW. I estimated that 25 TWh is 8.56 GW x 8 hr/d x 365 d/yr. So, that means idling at least 21% of the ENTIRE US wind capacity every night, all night, all year, AND assuming that the entire fleet produces at 100% during that time. Nope, that ain't happening.
Sorry, more sensationalism.
Yes, there was some curtailment as discussed in this thread: http://www.mynissanleaf.com/viewtopic.php?f=13&t=4099, but not all night, every night.

I suppose, it I spent some brainpower, I could come up with 25 TWh of unused "capacity" or something similar, but that is not actual curtailment or lost revenue. If you look at this week's power production/consumption at http://transmission.bpa.gov/Business/Op ... ltwg3.aspx you'll see the wind is being used right now, even with very high hydro production and water runoff.

So, yes, charge at night, and charge as much as possible during the spring run off! Let's take those vacations during May and June, consuming as many of the "good" electrons as possible. Then when the summer heat hits, turn off the A/C and take the bus/bicycle to the beach. Charge ON! Drive ON!.

Reddy

Re: Charge at night! - 25 TWh of Wind Power Idled in 2010

Posted: Mon Apr 30, 2012 4:08 pm
by DaveEV
Ran across this article today:

BPA orders NW wind farms to curtail production
The Bonneville Power Administration has ordered Pacific Northwest wind farms to cut production twice in recent days because it has a surplus of power from hydroelectric dams.


This article says: Bonneville Power calls for first wind shutdown of the season
In all 10,100 megawatt hours of wind energy was curtailed over the two-day.
That article also says that they are turning down nuclear power to help avoid further shutdowns.

Would be nice to get some credible numbers on how much wind exactly sits idle because of overcapacity and lack of transmission. I know it's a large problem in Texas right now.

Edit: This article says that 824,000 MWh were curtailed in the midwest in 2010: http://www.greentechmedia.com/articles/ ... s-turning/" onclick="window.open(this.href);return false;

Edit 2: One also has to wonder how much hydro power is lost due to overcapacity - after all - if the grid could suck down more power they'd be able to run more power through the turbines instead of spilling it... The reason wind has to be idled is so that the hydro guys can run more water through the turbines instead of spilling it...

Re: Charge at night! - 25 TWh of Wind Power Idled in 2010

Posted: Mon Apr 30, 2012 5:05 pm
by TomT
And then there is this...

"Wind farms can cause climate change, according to new research, that shows for the first time the new technology is already pushing up temperatures."

http://www.telegraph.co.uk/earth/earthn ... study.html" onclick="window.open(this.href);return false;

Re: Charge at night! - 25 TWh of Wind Power Idled in 2010

Posted: Mon Apr 30, 2012 5:07 pm
by GRA
drees wrote:Ran across this article today:

BPA orders NW wind farms to curtail production
The Bonneville Power Administration has ordered Pacific Northwest wind farms to cut production twice in recent days because it has a surplus of power from hydroelectric dams.


This article says: Bonneville Power calls for first wind shutdown of the season
In all 10,100 megawatt hours of wind energy was curtailed over the two-day.
That article also says that they are turning down nuclear power to help avoid further shutdowns.

Would be nice to get some credible numbers on how much wind exactly sits idle because of overcapacity and lack of transmission. I know it's a large problem in Texas right now.

Edit: This article says that 824,000 MWh were curtailed in the midwest in 2010: http://www.greentechmedia.com/articles/ ... s-turning/" onclick="window.open(this.href);return false;

Edit 2: One also has to wonder how much hydro power is lost due to overcapacity - after all - if the grid could suck down more power they'd be able to run more power through the turbines instead of spilling it... The reason wind has to be idled is so that the hydro guys can run more water through the turbines instead of spilling it...
I don't think that's the reason, I'd think it's more likely a cost issue. Hydro is cheaper than wind. This is a problem in Denmark, where they wind up subsidizing power in Norway and Sweden when the wind turbines are putting out near peak. Denmark doesn't have any way to use all the power, so sends it to Norway and Sweden where it replaces less expensive hydro. In effect the Danes are getting a negative price for their power, cause they buy hydro power back when the wind isn't blowing. That's the trouble with intermittent, non-dispatchable renewables.

In the PG&E service area, we're fortunate that the wind tends to blow strongest in the wee hours, unlike many places where the winds are strongest during the day (but often die out during the summer, when the need is greatest).

Re: Charge at night! - 25 TWh of Wind Power Idled in 2010

Posted: Mon Apr 30, 2012 6:17 pm
by DaveEV
GRA wrote:I don't think that's the reason, I'd think it's more likely a cost issue. Hydro is cheaper than wind.
Hydro isn't cheaper than wind when you have to pay the wind farms to stop producing. It must be cheaper than dumping too much water over the falls of hydro plants (which is illegal since too much spillover dirties up the water and harms fish) since they are shutting down wind farms to avoid spilling too much water.

Re: Charge at night! - 25 TWh of Wind Power Idled in 2010

Posted: Mon Apr 30, 2012 9:26 pm
by AndyH
The good news - wind as baseload! :)

http://www.stanford.edu/group/efmh/winds/aj07_jamc.pdf
abstract wrote:Wind is the world’s fastest growing electric energy source. Because it is intermittent, though, wind is not used to supply baseload electric power today. Interconnecting wind farms through the transmission grid is a simple and effective way of reducing deliverable wind power swings caused by wind intermittency. As more farms are interconnected in an array, wind speed correlation among sites decreases and so does the probability that all sites experience the same wind regime at the same time. The array consequently behaves more and more similarly to a single farm with steady wind speed and thus steady deliverable wind power. In this study, benefits of interconnecting wind farms were evaluated for 19 sites, located in the midwestern United States, with annual average wind speeds at 80 m above ground, the hub height of modern wind turbines, greater than 6.9 m s1 (class 3 or greater). It was found that an average of 33% and a maximum of 47% of yearly averaged wind power from interconnected farms can be used as reliable, baseload electric power. Equally significant, interconnecting multiple wind farms to a common point and then connecting that point to a far-away city can allow the long-distance portion of transmission capacity to be reduced, for example, by 20% with only a 1.6% loss of energy. Although most parameters, such as intermittency, improved less than linearly as the number of interconnected sites increased, no saturation of the benefits was found. Thus, the benefits of interconnection continue to increase with more and more interconnected sites.

Re: Charge at night! - 25 TWh of Wind Power Idled in 2010

Posted: Mon Apr 30, 2012 9:55 pm
by Nekota
AndyH wrote:The good news - wind as baseload! :)

http://www.stanford.edu/group/efmh/winds/aj07_jamc.pdf
abstract wrote:Wind is the world’s fastest growing electric energy source. Because it is intermittent, though, wind is not used to supply baseload electric power today. Interconnecting wind farms through the transmission grid is a simple and effective way of reducing deliverable wind power swings caused by wind intermittency. As more farms are interconnected in an array, wind speed correlation among sites decreases and so does the probability that all sites experience the same wind regime at the same time. The array consequently behaves more and more similarly to a single farm with steady wind speed and thus steady deliverable wind power. In this study, benefits of interconnecting wind farms were evaluated for 19 sites, located in the midwestern United States, with annual average wind speeds at 80 m above ground, the hub height of modern wind turbines, greater than 6.9 m s1 (class 3 or greater). It was found that an average of 33% and a maximum of 47% of yearly averaged wind power from interconnected farms can be used as reliable, baseload electric power. Equally significant, interconnecting multiple wind farms to a common point and then connecting that point to a far-away city can allow the long-distance portion of transmission capacity to be reduced, for example, by 20% with only a 1.6% loss of energy. Although most parameters, such as intermittency, improved less than linearly as the number of interconnected sites increased, no saturation of the benefits was found. Thus, the benefits of interconnection continue to increase with more and more interconnected sites.
I think Jacobson is a bit over the top when claiming that connecting to the transmission grid is simple.

Re: Charge at night! - 25 TWh of Wind Power Idled in 2010

Posted: Mon Apr 30, 2012 9:59 pm
by tbleakne
http://www.greentechmedia.com/articles/ ... s-turning/
Far and away the primary cause of curtailment is limited transmission, Moland said. There has in recent years been large-scale rapid development in the wind-rich Midwestern regions of the U.S. from the Canadian border to Texas, “where you get that 40 percent wind availability.” Transmission development has not kept pace.

“You can go from starting construction to delivering power at a wind site in twelve months, or even less, whereas building a transmission line to service a new site,” Moland said, “usually takes three to five years.”
We can hope transmission capacity will catch up.