Fact Check: Fred Udo’s Bogus Numbers on Wind and Emissions Savings
A new report (calling it a “study” would be giving it too much credence) on wind power and emissions is circulating in the anti-windosphere. Authored by Fred Udo, it makes the seemingly–and actually–goofy claim that emission reductions from wind, a zero-emissions energy source, are small.
By Tom Gray
How does Mr. Udo achieve this result? By looking at statistics for Ireland’s energy use that confuse emissions from direct heating (using fossil fuels) with emissions from electricity generation. This leads to erroneous results, but hey, as long as they make wind look bad, that’s the important thing.
Here’s more from AWEA Manager of Transmission Policy Michael Goggin:
There’s a large, well-established body of empirical evidence showing that as states like Colorado and Texas have added wind energy to their grids, their carbon dioxide emissions decreased by even more than had been expected. That data was used to directly refute an erroneous study by consulting firm Bentek even before the study came out 18 months ago, and the Bentek study has since been widely dismissed as the fossil fuel industry attack piece that it is, except for continued efforts by the fossil fuel industry to continue spreading its misinformation.
There are also dozens of power system studies conducted by utilities, government agencies, and independent grid operators showing that adding wind energy to the grid results in larger emissions savings than the 1:1 offset commonly expected, largely because additional wind energy forces inflexible coal plants to be taken offline for extended periods of time and the share of their output not directly replaced by wind is replaced with more flexible and cleaner natural gas generation. I won’t waste time repeating the full discrediting of the Bentek study that has already taken place, but you can read through that with the numerous links at the bottom of this article.
Regarding Fred Udo’s report on wind and emissions in Ireland, it only took a few minutes to unravel the statistical trick Mr. Udo was using to get his results, which might explain why his analysis wasn’t published in a peer-reviewed journal and rather appears on an obscure Dutch anti-wind website.
This appears to be a classic case of a lurking (or confounding) variable being used to misleadingly present correlation as causality; a comparable example is arguing that cigarette lighters cause lung disease since people who buy them tend to develop lung disease. In this case, the lurking variable that is the actual causal factor appears to be cold weather and its impact on heating demand, data that Mr. Udo should have had access to but that (for reasons we can only speculate) he chose not to use in his correlational analysis.
What tipped me off was part 3, Figure 3 of his text, where Mr. Udo called out an event in Ireland around June 9-12, 2011, when the carbon intensity of Ireland’s electricity production surged. I was curious as to what might have caused that event so, on a hunch, I pulled weather records for Ireland. Sure enough, there was an abnormally cold spell when temperatures fell into the 30’s and 40’s F, 10 to 20 degrees below normal for that time of year.
Aha! Cold temperatures drive heating demand, forcing Ireland’s numerous fossil-fired combined heat and power (CHP) plants to fire up and run at a high level of heat production (and subsequently more emissions per megawatt-hour, MWh, of electricity, since CHP plants relative to the rest of the fleet are not optimized for electricity production, and CHP plants being run to produce maximum heat are not being operated in a way that is optimized for electricity production.
Moreover, it appears that the emissions associated with heat production are rolled into the data that Mr. Udo is using, so a CHP plant producing only or mostly heat and little or no electricity under cold conditions like these would score at infinite emissions/MWh). A smaller possible factor is that higher demand for electric heating drives higher merit order, less-efficient fossil plants to operate to meet the abnormally high electric demand.
As one would expect, cold spells and home heating demand often correlate with high wind speeds, which is how Mr. Udo was able to draw his false conclusion that wind was the causal factor. Sure enough, a closer examination of the spikes in emissions/MWh in his data show that all are associated with cold spells, and only some are associated with an increase in wind output.
It doesn’t take a statistician to tell you which is the causal factor in that relationship. Had Mr. Udo himself been more interested in finding the actual causal relationship at play here, he might have noted that the correlations between wind output and emissions intensity varied widely from month to month (as one would expect for weather-driven seasonal changes in electric demand), usually a strong indication that another variable may be the actual causal factor.
I should also point out that, contrary to Mr. Udo’s claims, the method Irish utility system operator EirGrid uses to calculate emissions savings from wind is accurate. The plant-specific heat rate curve that they are using would account for all of the impacts wind energy would have on the efficiency of the fossil fleets under all operating conditions.
As mentioned earlier, here are summaries of the evidence refuting the Bentek studies on wind and emissions:
http://www.renewableenergyworld.com/rea/news/article/2010/09/the-facts-about-wind-energy-and-emissions
http://archive.awea.org/newsroom/pdf/04_05_2010_Colorado_emissions_response.pdf
http://www.awea.org/newsroom/realstories/The-Facts-about-Wind-Energy-and-Emissions.cfm
http://www.awea.org/newsroom/realstories/upload/110720-The-Facts-about-Wind-Energy-and-Emissions.pdf
Filed Under: ARCHIVES • Feature Articles • Insight
Tags: Colorado wind energy • emissions reductrion • fossil fuels
Oil/Gas Industry: Trust us! We care, we really do. The rest of the us: No! 
Thanks for the info Fred! 
I think its a 10% mandate not 5%. 
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Thanks for highlighting all the great work the Northern Colorado Chapter of CRES is doing. One small but important correction--the ...
Comment by Dr. F. Udo on 11 September 2011:
There is one omission in the article: a proper reference to the work you describe as “bogus”.
Here it is for the reader that wants to check the bogus for himself:
http://www.clepair.net/IerlandUdo.html
Mr Goggins produces 3 arguments to dismiss the facts reported.
A.
“There’s a large, well-established body of empirical evidence showing
that as states like Colorado and Texas have added wind energy to their
grids, their carbon dioxide emissions decreased by even more than had
been expected. That data was used to directly refute the Bentek study
even before the study came out 18 months ago….”
This refutal (written by mr Goggins) is based on a government report containing a table of CO2 emissions:
“Table 7. Electric Power Industry Emissions Estimates, 1990 Through 2008 (Thousand Metric Tons)
This implies we have to replace measurements by estimates to meet the scienific standards of the AWEA.
B.
“In this case the lurking variable appears to be cold
weather and its impact on heating demand, data that Udo should have
had access to but that (for reasons you can speculate) he chose not to
use in his correlational analysis.”
Thanks for the suggestion, but why the December 2010 data does not show this sensitivity to low temperatures?
By the way: Ireland possesses not more than 300MW of CHP on a total capacity of 6700MW of conventional power stations.
More important for the variability of the data is the fact, that the only source of pumped storage in Ireland undergoes a major refit in 2011.
The rest of the paragraph about excessive power demand can be dismissed by checking the total power demand curves provided by Eirgrid. The curves show the normal day/night and weekend variation, modulated by a slow seasonal effect.
See: http://www.eirgrid.com and download the total demand data. A one month period produces 2880 datapoints spaced by a quarter of an hour.
C.
“I should also point out that, contrary to Udo’s claims, EirGrid’s
method of calculating the emissions savings of wind is accurate. The
plant-specific heat rate curve that they are using would account for
all of the impacts wind energy would have on the efficiency of the
fossil fleets under all operating conditions.”
Perhaps one better asks the people from Eigrid about their opinion.
They express doubts about their own CO2 calculator….
Dr. F. Udo
Comment by Dr. F. Udo on 13 September 2011:
In my first comment I referred to different calculations of the CO2 emissions. There are now three ways of calculating CO2 emissions due to wind energy.
1. The simple way is to take the total power E delivered by wind and declare, that this power E has not been produced by fossil fuel, so the reduction of fuel consumption is equal to the fuel necessary to produce power E. This method is generally used in promoting wind energy and it has been used to “refute” the Bentek data. In Europe this method has been critized to the point, that even wind promotors use it rarely anymore.
2. The next step to refine the calculation is to take into account the change in efficiency of a power station, when it is forced to run at partial load. One takes the efficiency curves which are known for each power station and uses them even during the time the power generator is being regulated to another power level. In the article this approach is called the static method, as this calculation does not consider the effect of regulating the power. Eirgrid uses this calculation for reporting CO2 emissions. This refinement alone is enough to produce the effects reported in the article.
3. The final step is to take into account the increase in fuel consumption, while changing the output of a large power station. This can only be done by the grid operator as he and he alone knows the exact distribution of the fuel mix on all moments of the day.
An example might clarify the differences between the 3 calculations.
A gas turbine goes within an hour from full load to 0,8 load and back to full load.
The efficiency at full load is 60% and at 0,8 of full load the efficiency is 56%.
The fuel saving would be in method 1: 20%, in method 2: 14%, in method 3: somewhere between 0% and 10%.
Finally I want to remark, that as from the 1rst of October the Irish consumer gets a price rise of at least 12% for his electricity.
Dr. F. Udo
Comment by Mike D. on 12 December 2011:
When Bonneville Power backs of their hydro because of wind , there is no reduction of C02 unlike if they were replacing coal. Why can this still be counted as a REC?
Comment by dennis grier on 9 May 2012:
Having just read Tom Gray’s article ‘Fred Udo’s bogus numbers’ I get the feeling I haven’t understood whats going on. Why is it necessary for words like ‘bogus numbers’, ‘anti windosphere’ , ‘goofy claims’ etc. One is led to think that any critisism of wind or solar power is something evil – a kind of blasphemy!
I would like to point out to Tom that a lot of big ‘capitalist’ companies are making a fortune out of wind and solar subsidies. This is accepted on the premise that these technologies will save us from the impending climate meltdown. In order to get a check on whether this is really true, some very careful and difficult measurments must be made on the real savings in gas consumption achieved by substituting ‘green’energy sources. One is measuring small percentages of large numbers; estimates are useless and only the best physics will offer some hope of finding the truth. If it is found to be true that the expected co2 savings from wind power is much less than expected then stupendous sums of money and materials will have been wasted. Fred Udo has at least made an honest effort to contribute to this analysis; you should at least treat his work with some respect.