The table at the end indicates that it should be OK at 125m, complying with the PAN45 "simplified noise condition" of 35dB, without needing to worry about background noise. Even at 25m it would comply with the standard used in Aberdeenshire for properties with a "financial involvement".
By the way, we'll be in Orkney for a few days later this month. Is there an Eoltec operating on the Mainland that could be viewed without any formality? We may possibly visit Sanday and Rousay but that's not yet decided.