I saw one of these on 534 at a residence lately. I became interested in getting one and after much investigation found it would take me 12 years to recover my investment and at that point the windmill would "possibly" need repairs. The never explained possibly but were excellent sales people. Almost had me fooled too.
Maybe a 15,000 dollar wood boiler could run its pump from a windmill and voila free heat. Oh yeah I have to pay D&R Central Boiler $550 over list price unless I pay cash too.