What I've been up to: electrifying my ride

Hi Rico,
E.ON Netz in 2005 produced its informative Wind Power Report, which clearly outlined the shortcomings of wind power.
At that time E.ON was the largest wind power generator in the world – and may still be. I think E.ON has very significant credibility when they openly discuss the main disadvantages of their very large wind power portfolio.
Summarizing the key points:
1. Note the very low Substitution Capacity from the E.ON Netz report: 8% dropping to 4% in 2020 – this is the key to why wind power is not economic. This means that German wind power requires almost 100% conventional backup power. Quoting the E.ON report: “As a result, the relative contribution of wind power to the guaranteed capacity of our supply system up to the year 2020 will fall continuously to around 4% (Figure 7). In concrete terms, this means that in 2020, with a forecast wind power capacity of over 48,000MW (Source: Dena grid study), 2,000MW of traditional power production can be replaced by these wind farms.”
2. Wind power output varies approximately as the cube power of the wind speed, so wind power causes huge, short-term fluctuations in power supplied to the grid, and can cause serious grid instability.
Quoting the E.ON report: “Handling such significant differences in feed-in levels poses a major challenge to grid operators.”
This report demonstrates the key flaw that is ignored in many analyses of wind power – wind does not blow enough when you need it, so wind power is ineffective at replacing conventional power stations, and the problem worsens as more wind power is added to the grid.
Best regards, Allan
P.S. Re nuclear plants supplying base load power – that works if there is not too much nuclear capacity as a total percentage of grid generating capacity – but look at Ontario and France, where nuclear predominates. The situation I described (underutilized overnight generating capacity) becomes much more significant as you add more and more nuclear power to the grid.
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Comments and excerpts:
E.ON Netz Wind Power Report 2005, Germany
http://www.eon-netz.com/EONNETZ_eng.jsp
Capacity Factor and Substitution Capacity (Capacity Credit)
E.ON states that in 2004 Germany had an installed wind power of 15369MW and an average feed-in of 2968MW or 19.3% Capacity Factor. In 2004 E.ON operated over 40% of the wind power in Germany (more than the entire installed USA wind capacity), so one assumes their numbers must be representative for their grid size, layout, wind speed, etc.
A very important sentence from the E.ON report is:
“In concrete terms, this means that in 2020, with a forecast wind power capacity of over 48,000MW, 2,000MW of traditional power production can be replaced by these wind farms.”
E.ON calls this factor Substitution Capacity (the US EIA calls it Capacity Credit) – Germany is now at 8% Substitution Capacity, which is low, but will decline to 4% by 2020 if all goes according to plan.
In summary, an analysis by a German industry leader, which operates more wind power than the entire USA, says it must install 12 to 24 times more wind power capacity than the conventional power that the wind power replaces.
Figure 7 of the E.ON report, entitled “Falling substitution capacity”, states:
“Guaranteed wind power capacity below ten percent – traditional power stations essential.
The more wind power capacity is in the grid, the lower the percentage of traditional generation it can replace.”
Full quotation, from page 9 of E.ON report:
In order to also guarantee reliable electricity supplies when wind farms produce little or no power, e.g. during periods of calm or storm-related shutdowns, traditional power station capacities must be available as a reserve. This means that wind farms can only replace traditional power station capacities to a limited degree.
An objective measure of the extent to which wind farms are able to replace traditional power stations, is the contribution towards guaranteed capacity which they make within an existing power station portfolio. Approximately this capacity may be dispensed within a traditional power station portfolio, without thereby prejudicing the level of supply reliability.
In 2004 two major German studies investigate the size of contribution that wind farms make towards guaranteed capacity. Both studies separately came to virtually identical conclusions, that wind energy currently contributes to
the secure production capacity of the system, by providing 8% of its installed capacity.
As wind power capacity rises, the lower availability of the wind farms determines the reliability of the system as a whole to an ever increasing extent. Consequently the greater reliability of traditional power stations becomes increasingly eclipsed.
As a result, the relative contribution of wind power to the guaranteed capacity of our supply system up to the year 2020 will fall continuously to around 4% (Figure 7). In concrete terms, this means that in 2020, with a forecast wind power capacity of over 48,000MW (Source: Dena grid study), 2,000MW of traditional power production can be replaced by these wind farms.
Figure 7. Falling substitution capacity
Guaranteed wind power capacity below ten percent – traditional power stations essential.
The more wind power capacity is in the grid, the lower the percentage of traditional generation it can replace.
Wind Variability and Grid Operability
The E.ON report states:
Whilst wind power feed-in at 9.15am on Christmas Eve reached its maximum for the year at 6,024MW, it fell to below 2,000MW within only 10 hours, a difference of over 4,000MW. This corresponds to the capacity of 8 x 500MW coal fired power station blocks.
Full quotation, from page 8 of E.ON report:
FIGURE 5 shows the annual curve of wind power feed-in in the E.ON control area for 2004, from which it is possible to derive the wind power feed-in during the past year:
1.The highest wind power feed-in in the E.ON grid was just above 6,000MW for a brief period, or put another way the feed-in was around 85% of the installed wind power capacity at the time.
2.The average feed-in over the year was 1,295MW, around one fifth of the average installed wind power capacity over the year.
3. Over half of the year, the wind power feed-in was less than 14% of the average installed wind power capacity over the year.
The feed-in capacity can change frequently within a few hours. This is shown in FIGURE 6, which reproduces the course of wind power feed-in during the Christmas week from 20 to 26 December 2004. Whilst wind power feed-in at 9.15am on Christmas Eve reached its maximum for the year at 6,024MW, it fell to below 2,000MW within only 10 hours, a difference of over 4,000MW. This corresponds to the capacity of 8 x 500MW coal fired power station blocks. On Boxing Day, wind power feed-in in the E.ON grid fell to below 40MW.
Handling such significant differences in feed-in levels poses a major challenge to grid operators.