Hello! First post and it's a long one so sorry.
I've searched this forum and others as well and continue to be stunned by the utter lack of long term results, particularly for commercially made small wind turbines. If you do find anything it's for the Hugh Piggott brake drum design which have amazing longevity.
SparWeb and Adrian thanks for the links and suggestions to the Netherlands report. I've taken the time to scan all those reports.
I was very impressed that most of turbines made it 4 years in the Nederland's test. Best I could tell is that sadly most (all?) of those companies are now gone.
That NREL link isn't about long term turbine test results. Rather it's about the testing site details and the testing methods but I didn't see any mention of specific turbines results.
I did search NREL using numerous search terms and did not find any studies, short or long term, that detail the production (or anything) of a small wind turbine. Granted I'm not most savvy searcher.
Regarding SWCC:
SWCC puts the Bergey 10 at 13,842 annual KWH's at a 5MS (11.1MPH) site which to be honest floored me. I'm trying to rationalize that with just how far apart from the production numbers I've personally seen. So that's an average of 1154 KWH/month which at most sites would likely work out to the some months being over 3,000 and others being less than 500.
I've been around almost ten Bergey 10's. All of them were well sited on 100' or taller towers with conservative annual wind speeds of 11 to 15 mph verified by wind maps and on site dataloggers.
On thier BEST months not a single one of them ever exceeded or even got close 1150kWH. Keep in mind SWCC rates them at an average of 1,153 KWH/month. Some of them would hit 700 kWh/month just one or twice per year then spend the rest of the time struggling to get past 200 kWh/month. None of them ever made more than 5,000 kWH in a year. A pretty stunning difference between the SWCC number of almost 14,000kWH.
So I spent sometime trying to understand the difference between what I saw with vs. what was claimed. Turns out that SWCC isn't actually testing anything itself but please spend a few minutes on thier website to verify for yourself.
ICC-SWCC does not conduct tests, but verifies and certifies test results submitted by approved testing organizations. Applicants should obtain ICC-SWCC approval for the use of a testing facility before commencing work to ensure that the resulting test report can be used for ICC-SWCC certification.
Look what else I found in the application process.
"Testing
Applicants who have not already conducted testing, may choose to use testing laboratories that are accredited or non-accredited to ISO 17025 or conduct the testing themselves (subject to ICC-SWCC requirements). "
Manufacturers are allowed to self certify thier turbines so keep that in mind when you suggest that people look for SWCC.
If you read any part of this as argumentative please don't because it wasn't meant to be. I'm just a guy who's been burned and seen a lot of people burned badly by small wind manufacturers. I'm just trying to help others know what they are they getting themselves into should they choose to buy a commercially made small wind turbine.
It's quite worth noting that High Piggott has helped many people DIY what almost no manufacturer has been able to do.