“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.…

“The level of emissions savings provided by wind plants has never been conclusively determined, taking into account all the factors.”

Part I yesterday questioned the analysis and robustness of Joseph Cullen’s study, “Measuring the Environmental Benefits of Wind-Generated Electricity”. [1] Part II completes the commentary on this paper, covering:

• Questionable data, which seriously inhibits any analysis of wind performance
• Interstate trade in electricity, an often overlooked, but important, consideration in understanding impacts on emissions
• A summary of the acknowledged shortcomings of this paper
• Questionable opinions/claims made

Questionable Data

The level of emissions savings provided by wind plants has never been conclusively determined, taking into account all the factors. Further, there is no published accurate, minute-by-minute, actual fuel consumption or emissions by individual plant, especially for systems with notable levels of wind present.…

[Editor’s note: Parts I-III provided insight into the complexities involved in any analysis of the Danish electricity system, showing (1) how unique the Denmark situation is, (2) that the details of electricity exports and imports must be understood for each of Denmark’s trading partners, (3) the likelihood that most of Denmark’s wind production is exported, and (4) an indication that the upper limit for manageable wind penetration is in the mid-single digits as a percent of domestic demand. Part IV now looks at the impact on CO₂ emissions.]

Figure 1 is a simple look at CO₂ emissions and wind electricity production, which explains the claims made by wind proponents based on a superficial examination of the information. Figure 1 shows what the Danish Energy Agency (DEA) reports based on an “adjustment” of actual CO₂ emissions.…

[Editor’s note: Parts I and II set the stage for the development of some conclusions about how much wind electricity Denmark exports, which will be provided in this post. The impact of wind on CO₂ emissions  is addressed in Part IV]

To further reduce the total amount of information to a more manageable level, the following is a look at this from the point of view of Denmark’s electricity import/export flows for the most recent “normal” year (2004), dry year, (2006), and a wet year, (2007), these conditions being the main driver of exports. This is shown graphically in Figures 1-3, starting with a normal year. In these charts numbers may not exactly balance due to rounding. Note in particular the net export levels, which are typical for each type of year.…