We have had the Proven turbine since 2009 and the Kingspan once since 2012. They have different brand labels because Proven went bankrupt and were bought out by Kingspan. Underneath the wrapper they are identical. There is no difference in materials used or design between the 2 turbines. However the Kingspan out performs the Proven dramatically - generating on average over the 2 years about 80% more power. That is too big an amount to be attributed to site differences.
Last winter N the Mull based turbine installer, who has his own Proven turbines, came to look at the set up and see if he could help address the issue. He reprogrammed the inverter on the Proven but it didn't improve anything.
Today D from Border Hydro, once they had serviced the Kingspan turbine, went to investigate the Proven inverter to see if he could pinpoint any thing. He adjusted the levels slightly so that the Proven will start generating at low amps, which should harvest some of the slower wind speed.
The other D mentioned the heater installed on the Kingspan, which takes the excess energy from the turbine once it starts to generate more than full power in high winds - the heater acting as a power dump. The Proven doesn't have this system. Instead it turns itself off so as not to damage the turbine.
Aha. We didn't know that. Perhaps this is the explanation we have been hoping for. There is a blue light on the Proven generation panel. If that is not lit during high winds, then the safety mechanism has turned the generation off.
These 2 factors could explain the difference. Or some of it. I have some windy weather monitoring to do, to see if we can get to the bottom of it once and for all!
There is a big storm coming in the middle of the week, so I will be rushing out to check on the blue light.
This old Blackface tup is waiting in the fank for Farmer to take him down to the Haunn area to join the hill ewes.
The day has been bitterly cold, but the light has played a dramatic game all day, with clouds moving across the sky, changing colours, bringing rain and hail and rainbows.
More and more starlings are gathering around the cattle shed. It is a wonderful sight to see.