Small wind turbines criticised

Encraft have just published their report on small wind turbines, known as the Warwick Wind Trials, which was supported by the British Wind Energy Association and the Micropower Council. The full report can be downloaded here.

The report states that:

The average energy generated per turbine per day across the sample set has been 214 Wh (including times when turbines were switched off for maintenance or due to failures). This is equivalent to an average of 78 kWh of energy produced per site per year and an average capacity factor of 0.85%. (This compares to typical capacity factors of between 10% and 30% for larger turbines on free standing sites in good areas).

If the results are adjusted to exclude data from periods when turbines were switched off or broken the average energy generated per turbine per day rises to 628 Wh (230kWh per year equivalent) and an average capacity factor of 4.15%.

Of particular note is that turbines on our high rise sites, Eden, Ashton and Southorn Court were able generate as much energy in one month as other turbines in the trial did in one year. It is unfortunate that these high performing turbines had to remain switched off for the majority of the trial following complaints about noise from the building residents.

and comes to the conclusion:

Overall the trial has painted a picture of an industry and technology that is still at development stage and is likely to make a tangible contribution to energy and carbon saving only on the most exposed sites and tallest buildings. The combination of this reality, aggressive and over-optimistic marketing by some suppliers, and the enthusiasm and credulity of the market (and regulators) has potentially led to an unfortunate outcome where the wind industry as a whole is in danger of suffering from a setback in credibility.

The evidence form this trial is that such potential setbacks can be avoided in future by greater openness by the industry as a whole, and more effort to educate the market and opinion formers about the fundamental science and challenges of new technologies earlier. Micro-technologies need not fear customer resistance, because there are plenty of early adopters out there willing to give things a go. Sustainable technologies and a sustainable future require customers who are properly informed and able to take individual decisions that are both economically optimal and environmentally sustainable. Without open data this is impossible.

To get the whole picture, make sure you download the full report, which includes detailed data on the trials.