I just looked at he Community page (because the messaging isn't working) and came across this about the planning consent:
29. All turbines shall be shut down for a period of three hours from sunset during the months of May to August when temperatures are above 10 decree Celsius and wind speeds are 6m/s or less. All measurements will be based on measurements at the turbine nacelle and wind speed based on a 10 minute average. This restriction to operation hours shall apply in perpetuity unless otherwise agreed in writing by the planning authority. Any request to the planning authority to vary this restriction shall be accompanied by a postconstruction monitoring report.
Reason: To ensure that the wind farm has no significant adverse effects on the conservation status of Nyctalus bats.
This is entirely appropriate to ensure safe feeding by the UK's largest bat. But it does mean that the turbines could be shutdown for 4% of the year for this. I presume the modelling of the output and payback has taken this into account?
and a reply
yes that's been accounted for. It won't happen as much as 4% of the year because even in summer it definitely won't always be above 10 degrees during those times (from personal experience I can confirm it's a cold hillside)! But even so, any loss in yield during these periods won't be proportional to the time they are shut down because when wind speeds are that low the turbines will be generating very little energy anyway.
and an even more surprising follow-up (not posted April 1st, I checked):
Have you ever passed a wind farm & noticed that most of the turbines are spinning, however even though it's a windy day, at least one isn't turning? This is because the top of the turbine is connected to the ground wiring via a thick cable in the centre. This prevents the top of the turbine from rotating endlessly around and around to face the wind direction.
So this cable doesn't break, every now & then, the turbine needs to stop spinning & unwind the central cable before it can start work again.
This is normal practice. So to have a daily "bat" downtime means all the turbines can unwind at the same time ready for the next gust of wind.
Therefore I wouldn't worry about the 4% downtime if I were you, it's insignificant as all wind turbines have some downtime.
