BFL13 wrote:
harold1946 wrote:
My question is how were you able to maintain 70 degrees panel temperature throughout the testing?
He said 70F was ambient throughout and panels heated up right away so presume also maintained steady temp at 28C above ambient as he reported.
In my recent test of a panel, taking it out from the cool temp garage, it showed 37v Voc immediately, as rated, but very quickly that dropped to 36v as panel heated up. You could feel the glass was now warmer than it was at first. Happened fast.
BFL, I didn't pay lots of attention to time, but I'll bet my panels took less than 5 minutes to warm up in direct sun. Is that consistent with what you observed??
And, yes, one nice thing is that the daytime temps from about 11AM PDT through about 3PM PDT were very constant, right in the 70F range. Much better than trying to do experiments in mid summer when daytime temps are constantly changing.
And I did take panel temps with my IR thermometer every half hour or so and they stayed pretty constant. IR thermometers,(at least mine) is notorious for reading variability. 10F or so on repeated measurements isn't uncommon on mine, but they all were in the same range.
