“Michael Goggin says that attacking the validity of the CEMS data is a sure sign of desperation. But it can be argued that any possible desperation is on the other side.”

In my 2014 post Where Wind Studies Go Wrong: Cullen in AEJ (Part II) , Michael Goggin of the Amercian Wind Energy Association (AWEA) made a comment that recently came to my attention, which deserves a rebuttal despite the lapse of time. My 2014 post critiqued a paper by Joseph Cullen, Measuring the Environmental Benefits of Wind-Generated Electricity.

In summary, Goggin’s points were as follows:

• I said EPA’s Continuous Emissions Measurement System (CEMS) measurement was on an hourly basis and thus understated the real cycling-related emissions from wind power as a result. (Goggin says CEMS takes emissions measurements every 15 minutes and reports hourly based on averaging these results.)

“The best approach to understanding wind’s impact appears to be that properly structured ‘bench’ tests should be performed, and results made publically available, on actual fossil fuel plants under the full range of conditions experienced in balancing the effect of the presence of wind’s generation behavior.”

Part I on Tuesday and Part II yesterday focussed on the greater range of variations and the increased ramping levels caused by wind in short time intervals of a few minutes or less, and introduced some of the complexities involved in analysis of the impact of wind in an electricity system.

This post looks at the analysis of published fossil fuel consumption and emissions information and addresses two major issues:

(1) the questionable nature of the published information, and

(2) the questionable attempts by external analysts (those outside the information publisher organizations) using this information to determine the cause and effect relationship between wind production and fossil fuel consumption and emissions leading to the determination of savings with wind.…

“Understanding the impact of wind requires very detailed analysis of ramping events on a short term basis. The analysis provided here raises even more questions, so there is still much to be learned to properly quantify any impact from the presence of wind on fossil fuel or emissions savings. Arguably the complexity involved defies analysis.”

“Wind increases the magnitude of the balancing activity by increasing the ramping over load alone with a notable number of large ‘outliers’. The dynamic impact of this can substantially increase the rate of fossil fuel consumption and emissions in fossil fuel plants in the net load balancing role over that claimed by any less rigorous analysis.”

Part I yesterday in this three-part series examined wind intermittency/integration basics. Part II today focuses on the ramping impacts of the combination of load and wind (net load).…

“Analyses of wind impact on emissions do not take the impact of the highly variable and unreliable wind generation fully into account, especially in short term intervals, and can be discounted as not providing conclusive results.”

This three part series will illustrate the problems in properly evaluating the impact of unstable generation sources (wind and solar) in electricity systems. It will be seen that the complexity involved makes it virtually impossible to analyze all the necessary factors, and the use of sophisticated mathematics, especially statistical approaches, cannot compensate for this. Further complicating this, any analysis relying on published fuel consumption or emissions is made even more inconclusive because of the questionable nature of this information.

A basic problem is the erratic behaviour of wind in the short term (a few minutes or less) and unreliable in the longer term (hours and days).…