Wind energy - fundamentally flawed
As an engineer who has spent many years in the power generation industry I
am extremely concerned at the way the U.K. is pursuing the wind energy
option and spending billions of pounds without the basic facts being made
available to the general public.
The primary questions that need to be answered are:-
1. How much wind energy has been delivered to and used by the British Grid
to date?
It is most important to know how much energy is being actually supplied to
the Grid and not what is theoretically available at the output from the
turbines when the wind is theoretically blowing at the optimum turbine
design speed.
2. What is the spend to date? The cost of the wind turbines and associated
structures, the construction costs, land rental costs, the extensions to
the grid and all those other costs associated with the project.
- These costs should be separated into:-
2.1 Initial Cost, including any grants and subsidies.
2.2 Operating costs including subsidies that will be required to continue generation.
The above information is critical to the whole wind turbine programme .
We hear statements from the media and ministers about the ability of the wind farms to supply cities of certain sized populations with their electricity requirements ignoring the fundamental fact that they can only do this when the wind is blowing at the appropriate time and at the appropriate velocity.
A recent study carried out by a German energy company showed that the 48 gigawatts of proposed capacity will equate to only 2 gigawatts of useful capacity.
In Denmark in 2004 only 6% of the potential wind energy available could be used because of the mis-match between supply and demand.
Other very relevant factors :-
3. The energy in the wind varies as the cube of the wind velocity.
The wind design velocity assumed by wind turbine designers varies. Some use 12 metres/sec. others use 11 metres/sec, which is about 25 miles per hour.
If one looks at the BBC weather forecasts the wind speeds (quoted in miles per hour) very rarely exceed 10mph, 40% of the design speed. At this speed the turbine will deliver 6% of its rated output.
At 5mph wind speed the turbine will deliver less than 1% of its rated output.
4. If the wind is blowing at a rate that gives a useful output from the turbine but it is at night time in the warmer weather and the grid demand is being satisfied by nuclear base load then the wind energy would not be used.
5. In the very cold weather there is frequently little or no wind and of course .there will be no output from the turbine
6 If gales are occurring the turbines must be shut down to prevent damage .
People generally are anxious to reduce the pollution of the planet but to embark upon a proposed solution that appears so fundamentally flawed is obviously futile.
D.D., F.I.Mech E
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