Just noticed this on one of WN's ebay ads. Smokin' power! I've also integrated this into one of my Small Wind Power Chart vids. The Windtura 750 beats the $3000 Bergey XL.1 at the high end. Amazing! http://www.youtube.com/watch?v=zBIUBB742uI
And this is why for the past year we have been going through testing pains with the 750 in trying to tune properly to inverter systems such as SWEA due to potential power the Windy 750 has been producing off my tower ! A more simple solution as these inverters develop in technology would to take advantage of the MPPT inverter systems with auto volt overload, this would be a better match for the Windy 750. BUT I think your monitoring these tests are very important because the testing and power charts are targeted to battery banks. I am glad to now see the charts reflecting both 12 V as well as 24 V. That was a issing link for a long time. My question then leads too, how much will those charts differ when feeding a grid tie inverter and taking into account the type of inverter you are using = what volt start up & is it using MPPT, etc. Anyways keep up the great work Minnesota . Murray
Thanks Murray, I agree on the MPPT question. I've heard conflicting info on GTIs with MPPT with turbines. There was even a contest held to design one and there were no winners! All entries made less power than what went into a battery bank (the control). It must be far harder than for solar panels which are relatively stable. Another point on testing - I took the data from 3 runs on a Hugh Piggott unit to show that the power curve has some significant variation based on the conditions of the day. This suggests that WN may want to established some user sites using the final version of the system, and add a logger. The power curve likely would improve vs. the truck-based test that was used to generate the current curves. Here is the VID showing my analysis. Good wind, Minnesota
I watched an interview / documentary on Pincher Creek Alberta, that is Canadas biggest wind farm. The operations manager stated that wind farms in colder climates are at an advantage because of the fact that cold air carries more potential energy than warm ! This gives much credit to your comment "conditions of the day". This means that 20 mph in warm air may not produce as much energy as 20 mph in cold air ! So as you were saying if there were more user site tests, taking into account their location there would very likely be a difference in the power curve done on the truck. If more of those sites had colder or more dense air it could very well be in favor of the WN power curve chart ! Lots of possible variables isn't there . Will check your Vid tonight. Murray
Yes, density of air is a factor. I am a pilot and wings do not fly as good on hot days because the air molecules are farther apart (less dense). One thing I forgot to mention in the vid is that the wind from different directions at a site is also a big factor, and could be the reason for "choppy" data. Few sites are totally flat and clear of obstructions equally in all directions.
I agree, Murry and thanks for all your testing with the 750 in combination with the SWEA controllers. etc ...! Very interesting work Minnesota. Great video!! More on-site data certainly can be very helpful to fill in the gaps ... as you have shown here. I had no idea that the power curves would differ so much on the same unit. I can really see how data gathered at a particular site over time could then be programmed into an MPPT controller, such as the Midnite Classic, accessed per specific conditions and and used to assist control. Wind directions, temperature, steady or gusting winds etc. could each play a role in getting the most from less than ideal conditions. Looks like Midnite is going to need to add a few more RJ45 jacks and program in a few more algorithms. Great work guys ... thanks! Dave
