SWIEP postings and corrections

[Mel Tyree]

Hi all,

Occassionaly I like to double post reports from SWIEP to Green Power Talk, which is my favorite forum! So I started this thread for some of those posts and corrections.

Re: Eating crow or Revised comments about Bergey Blades.

SWIEP is a consumer oriented ‘Small Wind Information Exchange Program’ founded on the ideal that ‘an educated buyer is a wise buyer’. The purpose of the group and website is to provide technical information and reliability information about small wind turbines. As moderator of SWIEP, I strive for presenting factual information. Hence my aim is to continually correct posted information as new facts appear.

I have to make a major correction to R#23 which can be downloaded from:
http://www.ualberta.ca/~mtyree/SWIEP/Publications.html
This report deals with claims from Bergey Windpower Corp (BWC) regarding advances in their redesigned airfoils (blades). Please read the revised report to see what errors were made and how I discovered the need to correct the report. I feel the error is understandable, but I apologize to Mike Bergey for not contacting him to confirm that information in his PowerPoint Presentation was correct.

My failure to check the facts in May 2008 resulted in an unjustified criticism of BWC. Sorry!


Mel Tyree
PS to save you going to SWIEP I have uploaded the pdf file.

[Mel Tyree]

Hi all,
I think it was Matt Tritt who said that folks out his area (Montana) partly furl their Bergey to avoid shut down of the GridTek10 inverter when it is really windy. As many of you know, the Bergey inverter is undersized (mismatched) compared to the generator. So I decided to try the idea of furling.

SURPRISE! It doesn't help very much. Even a fully furled Excel-s produces enough power to knock out the GridTek10.
If you want to know more download R#46 from http://www.ualberta.ca/~mtyree/SWIEP/Publications.html

Happy reading and happy new year!
Mel

[Mel Tyree]

Hi,
I don't know if anyone in Green Power Talk is reading my SWIEP postings on SWIEP or at GPT. Anyway here is a model I have been working on that provides some information on how fast a small trubine responds to changes in wind speed.
Does anyone know of similar studies? I am serving as the MSc examiner for a grad student in Mechanical Engineering who has collected a year's worth of 1 Hz data on a little AirX so we will try the DIRM model on that too. If this is a new approach we will try to publish...if it is new.
--Mel
Moderator of SWIEP

[Paul Bailey]

Hi Mel : I've followed all your posts with great interest on GPT but not SWEIP> Really interested in your reasearch and datalogging capabilities . Thanks for keeping us updated here at Green Power ,Nice to see some hands on user data from a real world wind application with an Unbiased summary positive / or negative.. Anybody you know testing the Skystream and datalogging, independant from what its own controller tells you. Thanks Paul :rolleyes: ( Mel : any new follow up to your ground source heat pump posting awhile back that I particularly enjoyed??)

[Mel Tyree]

Paul,
I am still collecting data on my GHP (1 Hz samples of power use by the GHP, water pump, air temp and water temp). I also collect Degree Heating Days at my home. I have detected a drop in efficiency since I started. Initially I got 0.93 kWh/HDD but now it is more like 1.15 kWh/HDD. The initial estimate was based on short term measurements done manually (1 or 2 h intervals when I had time to do it). So maybe there were errors.?
A loss of efficiency could occur if the hot and cold heat exchangers have built up carbonate scale. I have acid flushed both with not much coming out. A loss of efficiency could occur if the input water temperature has fallen, but I can’t detect any drop in input water temperature.
A loss in efficiency could occur if I have lost some refrigerant gas/liquid. I would have to pump out and weigh the refrigerant to test that idea but that takes skill and special equipment. So far I have not found ANY HVAC guy in Clinton County, NY, willing to do that for me. This is a potentially serious problem in terms of long-range service needs.
I called up Heat Controllers, who built the GHP, to see if they generally expect a loss of efficiency as a GHP ages in the first year. They don’t know because they don’t do long term monitoring.
I have to check my data more carefully, but I think there has been a slight drop in output air temperature (from 97? to 92 F). So I have to check out past numbers. Also I have to see if the air side of the heat exchanger is dirty, but the air-filters seem fine so this doesn’t seem a likely cause either.

ON THE OTHER HAND, something might have changed in my house! Insulation may have been displaced. I have a storage space in the upstairs bedroom with exposed rafters above and the wind blew out the vapor barrier and some fiberglass bats. I fixed that over Xmas break. But I have to cut thru some drywall on the other side of the upstairs bedroom to see if I have the same problem there. So maybe my GHP is okay and the house isn't:wondering:
--Mel
ps when I figure out what is going on I will post another report.:D

[Mel Tyree]

Hi all,
I hope this reply (SWIEP posting R#49 on http://www.ualberta.ca/~mtyree/SWIEP/Publications.html) will address some of the last areas of disagreement between me and Mike Bergey and Michael Klemen. If not may I suggest we talk in private and then I will promise to post a summary of our discussions giving details of (1) what we have agreed on and (2) what we have agreed to disagree on. Sorry the SWIEP posing will not be immediately available. My University system drive is not available to me at this moment. For those of you who have access to Green Power Talk Forum it is uploaded now. For those of you who are in the CC list my response is attached. For the rest of you check in again on Thursday or Friday and I may have it uploaded to my 'samba drive' that contains SWIEP postings.
You might call this posting Epistle #3 to Michael Klemen, but he has not responded recently to any posting of mine. It might mean he is out of town, or sick of me or just plain sick? … or maybe we are in agreement. Anyway, I am always open to discussion.
--Mel

[Rob Beckers]

Mel, thank you for the update. I find your argument is clear and compelling. Seems to me that some people are in denial...

-RoB-

[Mel Tyree]

The message below sent to AWEA & SWIEP does not specifically reference GPT, but the sentements expressed here explains why I appreciate this forum so much! Contributors are polite and respectful.

Dear Michael,
I have noticed that you (and a few other members of AWEA) have a temper. You may remember that you once apologized to me for your temper. When I was younger I used to have a temper too, but I have gradually learned to bring it under control, but sometimes I slip back to my old ways too! I strive to be polite and respectful of others, and I have learned that I can do that and still disagree with others!
May I encourage all SWIEP and AWEA members to do that? Too often arguments are won by whoever can speak the loudest or say the most clever thing, but the winner of that kind of contest is not always correct. I have participated in group discussions between engineers where I have seen arguments won by he-who-speaks-the-loudest. So I was pleasantly surprised by a meeting I recently attended.
The occasion was when I served as the external examiner of a MSc candidate who did a project on small wind turbines. All examiners were engineers, except me. The student presented his results and the exam turned over to questions. The chief examiner had a copy of the thesis with yellow post-it notes sticking out everywhere! The thesis looked like it was in an advanced state of decay and yellow mushrooms were sprouting out everywhere. The chief examiner started out by asking the candidate if he could explain the ‘scientific method’ and how it applies to engineering studies. The candidate was shocked by the question but recovered to deliver a reasonable answer that satisfied the chief examiner. Then the examiner said: “I have placed post-it notes on every page where you say something without adequate proof. Adequate proof means that you either have to quote a publication that used the scientific method or you have to prove by measurements and analysis in your own study that you have arrived at the correct conclusion by the scientific method.” The student’s face was ashen! But he recovered and completed his oral exam okay (and passed pending changes to his thesis).
I was encouraged that some engineers believe in the scientific method. But the scientific method takes second place when ideas or replies are advanced in an atmosphere of anger. Anger stimulates the animal response in all of us to attack and defend, and logic often takes second or third place in that kind of exchange. As members of AWEA and SWIEP we are trying to advance our knowledge of small wind turbines, to critique unjustified claims, and to basically make the industry advance to produce better products that work better and benefit the customer. In my opinion, we can more easily get from where we are now to that better future if we are polite and respectful of the opinion of others and use the scientific method. We can do this and still have disagreements.

Anyway, that is how I see it.

Please download SWIEP R#51 to see my technical response to an old message from Michael Klemen. http://www.ualberta.ca/~mtyree/SWIEP/Publications.html

Best regards,

Mel Tyree, Moderator of SWIEP.

[Mel Tyree]

The following message was posted on SWIEP and S-W-H (AWEA) 3 days ago but has yet to appear on AWEA. In fact, my last three messages to AWEA have not appeared so I wonder if I am being censored for posting scientific opinions unpopular to some?

Hi All,
As many of you know, Mike Bergey and I have an honest disagreement about design faults in the 10 kW Excel-s turbine when connected to a GridTek10 inverter. Readers can download the Third Interim Report on energy loss (24.6% after 6 months). Download R#52 from SWIEP: http://www.ualberta.ca/~mtyree/SWIEP/Publications.html for many more details than in my last report. Mike Bergey and I still disagree. Mike’s arguments are based on a ‘simple and compelling’ theoretical computation using BWC’s WindCad model. I have responded in detail to Mike’s simple and compelling argument (R#50) after repeated attempts to talk to him personally failed.

The data in this report are actual measured data. Any experimental physicist will tell you that measured data ALWAYS trumps a theoretical calculation. Hence, if my data disagrees with the WindCad model, then the conclusions drawn from the model are wrong. I have explained in R#50 what I believe has gone wrong. I challenge BWC or Mike Bergey to respond to my many reports. BWC must: (1) defend the WindCad model, i.e., explain what is wrong with my analysis of the model, (2) explain why my measured data is in error.

I would much prefer to communicate with them privately and quietly, but they have refused to talk. Hence my options are limited. I could either remain silent even though I think I am correct or I can go public. I think current owners and potential buyers need the facts. Hence I have gone public.

My new report also takes a look at what I propose to do in the next 12 months to expand by study to inclued other 10 kW turbines. I submit this report about 3 days early because I plan to be in New Zealand most of March. If anyone makes a detailed response I WILL reply, but give me a few weeks because I will be away most of March 2009.

Best regards,

Mel Tyree Moderator of SWIEP
Professor
Department of Renewable Resources
444 Earth Sciences Building
University of Alberta
Edmonton, AB, Canada
T6G 2E3
780-492-5597 (Office)
780-902-6771 (Home)
518-594-3815 (Mobile)

[Rob Beckers]

Enjoy your trip to New Zealand Mel!
That's one place I would like to visit some day...

-RoB-

[Mel Tyree]

Hi to all,

I think members of SWIEP and Green Power Talk, might like to know that Small-Wind-Home (AWEA) is considering censoring my technical opinions on the AWEA public forum. They consider my last posting (SWIEP # 300) to be a rant. So I looked up ‘rant’ in Webster’s:
“RANT: intr.To speak or declaim in a violent, loud, or vehement manner: rave. To exclaim with violence or extravagance. n. Violent, loud, or extravagant speech.”

I think people will note that I have always tried to be polite and respectful of the opinions of others. However, that is not the same as agreement with everyone’s opinions. The ‘rant’ at issue here concerns my many postings of opinion on the theme of sources of energy loss when the BWC Excels turbine is connected to a GridTek10 inverter. I do not believe my many postings could be construed as a rant. It is repetitive in a way insofar as I repeat the theme, but each time I post I do something different, e.g., (1) include more scientific data which I collect at the expense of hundreds of hours of work and thousands of dollars of expense OR (2) make a detailed reply to a valid criticism of my analysis or measuring protocol OR (3) provide a new logical argument not previously expressed in quite the same way.

I feel my repeated postings cannot be considered a ‘rant’, rather it is careful scientific scholarship. Some people have responded to my postings saying they are convinced. Others are not. I respect all opinions whether readers agree with me all the time, only some of the time, or never. Nor do I claim I am correct. I make mistakes too. But I do strive to express only what I believe to be correct all the time even though I know I may be proved wrong in the future. But I do feel I have the right to express my opinion as long as it is done in a polite way with respect, data and reasoning. I do not equate politeness with agreement on issues. Even in private messages to Mike Bergey I have been polite. Yesterday Mike wrote to me in a polite manner and I responded in-kind thanking him for his reply and ending 'Best regards, Mel'.

If you want to see some examples of ‘rant’ that have appeared on AWEA in the past just review a few months of messages and you will see examples of person A claiming person B to be dishonest or person A literally calling for the blood of B and looking forward to the awaited-event of blood. I think this kind of ranting is unfortunate and as moderator of SWIEP I would never permit it. One instance might slip through but then the member would be removed from the list.

Many readers of SWIEP and GPT are frequent contributors to AWEA. I do not ask you to agree with my technical views, but I do ask you to Email the moderators of AWEA to express concern about censorship of my views or the views of anyone when they are expressed with respect to the views of others. You might start with a personal Email to
ian.woofenden@mindspring.com.

--Mel
PS - I wish I could spell! I wrote 'sensorship' in an earlier message.

[Rob Beckers]

Mel, you mean SWIEP posting #52? I can't find a #300 in the list.

-RoB-

[Mel Tyree]

Sorry about the confusion. I mean SWIEP publication #52 AND the notice of #52 in SWIEP Yahoo!Group posting #300.

[Mel Tyree]

Hi all,

I completed construction my Net-Zero Energy House in Jan 2008. The house is net-metered and powered by a 10 kW turbine + a 10 kW PV array producing about 19,300 kWh/year of energy. My home is also a zero-carbon emission home because it burns nothing to provide heat and hot water. Heat and central A/C is provided by a Geothermal Heat Pump (GHP). I have monitored the energy use of my GHP for half of the winter of 2007/8 and all the winter of 2008/9. Last year (May 2008) I posted a report on how well my GHP works. This year's report has some new information:
(1) Evidence that I am using more energy per heating degree day than last year (about 10 % more). When I have time I will examine my data in more detail to see if I can extract the reason. For now I make some suggestions.
(2) I have document how much the GHP offset the energy needed to provide electric hot water during the heating season.
(3) I measure the reactive loads of the electric motors in the water pump and GHP to make a minor correction on energy consumption.

The full report can be downloaded from R#54 from SWIEP also see a related excel sheet (R#55). http://www.ualberta.ca/~mtyree/SWIEP/Publications.html

People who install heating systems rarely monitor the energy efficiency of them so my report is fairly unique and provides an unbiased report of how well an open loop geothermal heat pump performs.

--Mel

[Mel Tyree]

Hi everyone,
I have completed a little study of BWC's new PowerSyncII inverter. This study compares the PowerSyncII efficiency to the GridTek10. Next on my wish-list is to compare an Aurora inverter connected to a Scirocco tubine and a WindyBoy connected to a Fortis Alize. Since I have to travel and pray for wind when I do these measurments, it might be several months from now before I can do it. I also try to answer some concerns of Michael Klemen raised when I posted R#41 (efficiency of the GridTek10).
Interested readers can download R#56 and supporting Excel sheets (R#57 & R#58) from:
http://www.ualberta.ca/~mtyree/SWIEP/Publications.html
--Mel
ps- R#56 is attached to this message:)

[Mel Tyree]

Hi,
I have uploaded a new file showing the efficiency of the PowerSyncII as measured by BWC. These data were posted by Tod Hanley of BWC! You will notice the efficiency is higher. Darryl Thayer wrote to me and said BWC probably measured the efficiency in steady state while their Bergey Excel-s was on a bench dynamo. Darryl has one and knows that BWC has one too. That explains why the power values in Tod's postings were at rather rounded values and evenly spaced.

Does anyone have any ideas that might explain why steady state measurements might yield higher efficiencies than mine where values are changing quickly because of rapid changes in wind velocity?
--Mel

[Mel Tyree]

Hi all,

I use clock-timers to measure wind speeds. Clock-timers are very precise except at low wind speeds, when false triggers of the clock-timer circuit can make you think there are hurricane-force winds when, in fact, winds are nearly calm. Has this happened to you? I attended an NREL conference last year and heard it happens to them. Those false values cause a few stray points on power curves, i.e., values of near zero power at very high wind speeds.

Did you know you can measure wind speed of an NRG#40C cup anemometer by measuring AC voltage? It works, and this could be a way to eliminate false-high values when winds are nearly calm.

To read my full report check my attachement or go to: http://www.ualberta.ca/~mtyree/SWIEP/Publications.html and download R#59.

I welcome comments and accounts of personal experience.


Mel Tyree,
Professor

[Mel Tyree]

Hi,
I just learned that NY State incentives will end soon. Does anyone know the official reason, if there is one? MA State ended incentives over a year ago because many of the MA small turbines were not performing well, but that is not the case in NY State. In fact I have instrumentation at 6 (soon to be 7) small turbine sites in NY State (anemometers, wind vanes, barometers, temperature sensors and OSI semitronics power meters etc). Most of these sites are quite good and hence the cost-benefits of buying a small turbine will be easy to prove. Once I have > 12 months of data I will release the data. I am also instrumenting two small turbines in Alberta, Canada, in cooperation with engineers in Alberta Agriculture (Department). Again we expect the cost benefits to be quite good in much of S. Alberta.

Background information on NYSERDA actions will be appreciated.
Thanks,
Mel

[Mel Tyree]

Hi,
I thought you might like a link to see this study. NREL followed the performance of five 10 kW Bergey's in WA State. NREL compared
(1) Predicted annual energy production prior to install based on predicted mean annual wind speed.
(2) Measured actual wind speed and ran the prediction again.
(3) Measured actual wind energy production.
Actual production was less than predicted by the model even after using the correct wind data! Based on 4 sites the ratio of actual energy production to model prediction based on actual wind speeds ranged from a low of 54% to a high of 81%!!
Seems to me there is something wrong with the model.
The report (2006) promised up a full report within a year but I have not found one. The report is too big for an attachment in GPT so here is a link:
http://www.ualberta.ca/~mtyree/SWIEP/Docs/PredictedVsMeasuredPerformancesinclair_rfv_operati onal_results.pdf

--Mel