Summertime Temps.
n3qik
Solar Expert Posts: 741 ✭✭
I have a homebuilt wind genny, I have noticed it is not producing as much power as it did 3 months ago. I think it has to due with the temp being 60-70 degs.( warmer but less dense air) instead of 30-40 degs. ( colder but more dense air ).
Am I right with this thinking or should I look at there is a problem??
Am I right with this thinking or should I look at there is a problem??
Comments
The only thing temperature should affect is your rectifier diodes. If they are not likening the temps, replace them with nice sturdy Schottky diodes, for a couple of bucks apiece. Measure the voltage drop across them with a O'scope, you may find a bad one, or they all are sick. They WILL need a heatsink, and maybe they are not properly thermal bonded to the the heatsink, or the cooling vents are plugged.
If you get magnets hot, they loose magnetism - I have no idea what would heat them up, and if the wires get hot, they burn a short or open. Compare resistance of each wire coil, see if one is way off from the others.
But generally, they are not heat sensitive like solar PV panels are.
|| Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||
|| VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A
solar: http://tinyurl.com/LMR-Solar
gen: http://tinyurl.com/LMR-Lister ,
Assuming that you have an accurate log of wind speeds--then we can look at Density Altitude--or basically, assuming a fixed pressure altitude (basically, dependent on weather) you can compare the density of the air at differing air temperatures.
Here is a readable link to a Density Altitude Compensation Chart (scroll down the page, near the bottom).
Assuming you are near sea level, the difference in altitude between 30F and 70F at sea level is, roughly, -2,000 feet (cold) vs +500 feet (warm).
Using the Bergy 1kW wind turbine spread sheet (.xls), this decreases the wind turbine output by about 6.9% because of the increased temperature...
Could you see it on your system--I am not sure unless it is pretty accurately instrumented.
-Bill
Thanks guys,
I have a wind gauge, but no logs.
During to winter I saw 5-10 amps, summer seeing about 1-5 amps. Both of this numbers at 20-30 MPH winds.
Since it was made from scrap parts, I guest I can't ask too much from it.
Today, she was bucking like a bronco. So I lowered the pole. Found two problems, first, the UHMW bearings are bad, second, one blade loosed an 6" part of the tip and another has a crack in it. I built it from scrap parts, guess it's time to return them back to the scrap pile. :grr:cry:
OUCH! It always hurts when you put a lot of time and effort into something that fails after a while. I know, been there, and you know the rest.
My 14 foot prop eventually suffered an "uncontrolled disassembly" during a storm. Most of it, I never did find, part of it was stuck in the barn roof like a broken knife in a pumpkin, but while it lasted, it was a sight to behold and worked beautifully. Alas, all good things must come to an end
Looks like your center blade has also developed a crack.
Peace
Wayne
Yep, that was about to fail also.
Have not found the missing part yet, guess I better start checking the neighbors roofs.
UHMW PE Bearings? Aren't those plastic bearings for pretty low RPM ( maybe a few hundred RPM at most--depending on shaft size) and relatively low temperatures (180F maximum--depending on composition)?
I don't know which happened first... Bearings went out of round and fractured you blades or the blade failed and pounded out the bearing...
-Bill
My bad, forgot to type the UHMW is for the yaw bearing. Opps.