Wind Power: The Damning Results

Here is the results from some analysis of the 3 month NETA Wind Turbine metered output. This NETA data is independant and used to pay power generators. There is no wishful thinking or political slant on this data. This data is freely available and continuously updated  HERE.

The snapshot I used is available HERE

The first graph below is a frequency plot of power output against half hour billing slots. It shows how often, within the 3 month period wind power contributed a particular power level (power level - X axis number of half hour periods - Y axis. (Sorry forgot to label the graph properly)

The most shocking outcome from this graph is that the most common output from the whole of the national metered wind power system is 300MW. That equates to  12% of their maximum rating of 2430MW. They were running at this level, or less for more than 30% of the 3 month period.

The graph indicates that while in the 3 month period the output fell to close to zero (less than 100MW ) for no less than (in-total) 147 hours, at no no time it ever reach anywhere near the often hyped maximum rating. In fact the total output never even reached 85% of this rating. The absolute maximum achieved was 2065MW (84.8%). This was achieved for (in-total) one hour in the three month period.

This graph below shows the half hourly power ratings linearly from  low to high. Wind energy is governed by a cube law. Double the wind speed and get 8 times as much power (unfortunately the reverse is also true - halve the speed get 1/8th the power). Here you can see the cube law in action and how it skews the output so most of the time wind power generation is  BELOW the Capacity Factor

The raw average (or capacity factor), which is arrived at by simply adding all readings up and then dividing by the number of readings gives an capacity factor  of 25%. (608MW) On their website the BWEA suggest it is 30%. Often the figure gets inflated further. The press blindly accept what they are told.

This otherwise laudable  Daily Mail Article   falls into exactly this trap.

Remember these NETA figures include offshore as well as onshore sites so the Capacity Factor is certain to be even poorer for on shore turbines alone.

The BWEA suggest that the capacity factor taken in isolation is meaningless. I (sort-of) agree with this. As electricity generation cannot be stored, the duration of the power generation operation is as important (or arguably more so) than the averaged value.

In this three month period the wind output only managed to reach or exceed this capacity factor (25% - 608MW) for less than 40% of the time. If you use the much hyped BWEA figure of a 30% capacity factor, then this value was only reached or exceeded for 23% of the 3 month period.

Due to the cube law relating wind speed and power output, we find that half the 3 months energy arrived in less than 25% of the time leaving the other half to cover the remaining 75% of the period. This is actually an improvement on the single facility figures of about 15% found in the USA (Lee Ranch Sample Data (1/2 way down this page) .

This improvement from 15% to less than 25% is the contribution from the grossly overstated "if its not blowing here its blowing somewhere else" argument. Clearly, in the UK, the power averaging due to the geographic separation of the turbines falls very far short of the usual bland statement that "things even out".

This is a graph of nuclear power output over this 3 month period. Notice how steady it is as it provides us with essential, solid, predictable Base Load generation. The variation is where the Power generator is matching demand not the result of a lack of "fuel" or wind (interestingly, there does appear to be a drop-out. and that, my friends is exactly what spinning reserve is for!)

The mess below is the wind power output for the same period.

It is a chaotic unpredictable set of short duration spikes smeared over a grindingly low background. How anyone could suggest that this can be used to reliably provide 30% of our power is beyond me. There are those though who even suggest that this could be used for base load power generation.

God help us all if the likes of Chris Huhne is stupid enough to continue pushing us down this road.

Love & Kisses


Adam Bell said...

Two problems with your analysis:

(1) No-one takes averages of wind production over a three-month period, as it's well known that production varies by season. Only a full year is useful when calculating capacity factor.

(2) NETA figures cover less than half the wind turbines in the UK. Current installed capacity is 5204MW.

BilloTheWisp said...

Hi Adam,

Thanks for the constructive criticism. here is my reply.

1. Yes, these figures are only 3 months data. But are you seriously suggesting that the following 9 months are going to "magic" the capacity factor up to over 30%? Besides, the capacity factor is the least of the problems. The big issue here is that 60% of the time the output was below this 25% capacity factor (that is 77% of the time if you use 30%). In fact the capacity factor was below 12% for a considerably longer period than it was above 30%.

2. Yes, the NETA data is a subset of the total installed wind turbine base. BUT it is truly indicative of the actual performance of wind power across the country. It is also statistically (easily) a large enough subset to provide accurate data. There are other reliable sources for similar data (particularly the CLOWD website). They have national wind speed figures going back to 2005. Their figures for a simulated wind turbine positions at each of the Met Office sites correlate with this NETA data.

I am more than happy to support productive schemes that reduce carbon emissions (or even plain old pollution). But they have to be viable schemes and not based on wishful thinking.

Thanks again for the comment.

Anonymous said...

You may find the following document of interest:

Helen Crow
DART (Dorset Against Rural Turbines)

glowworm said...

Bill o the wisp--
this is a superb post, leading the way with your spreadsheeting. I have freely used some of your material at
I will of course take it down (and do my own) if you don't like it. Keep up the good work

BilloTheWisp said...

Thats fine glowworm. Please feel free to use

Anonymous said...

GridWatch UK has graphs showing yearly output for ALL forms of generation, Nuclear, Gas, Coal etc.
It clearly shows useless WIND generated 3.2% last year, as info downloaded from the Grid in realtime, its difficult to argue with the stats.