The Classic reportedly has a snow melting feature. I have a camp in Maine that's off-grid. I have my panels on the roof, to keep away the people who would like to take them for themselves. This makes it very hard to clean the snow/ice off, and I'm very rarely there so I need a remote way to melt snow/ice 99% of the time anyways.
The camera I have for them shows a thin layer of ice/snow, which is making it so I produce next to nothing right now... the result is my generator kicks on every 36 hours or so as my batteries are getting decimated by heater fans, etc.
When my generator runs, I have about 12KW I can't use since I can only charge so fast with my 48V bank. I'd love to use up a bunch of power to melt the snow while it runs for 3 hours at a time. I have energy to waste!
I can't find any docs on this and I don't want to order a nearly $800 unit to replace a perfectly fine unit if the snow feature doesn't exist anymore.
Attempts to use roof ice-melt cables has proven to be mostly a waste of time, only little slices are cut in the ice that covers the panels.
Hi tgraves, welcome to the Forum.
There is some info in this Thread:
http://midniteftp.com/forum/index.php?topic=660.0
FWIW, Good luck, Vic
Thanks Vic. Was hoping there was some hidden options on the Classic I didn't find.
The backfeeding option is interesting, and I could hook something up to do that manually, but I don't know how to do that safely (from the panel's perspective).
We did not pursue the snow melting feature because although it might work in your case (thin layer of ice) it will not work in every case.
And, if the temperature is too much lower than freezing, it just doesn't make enough heat to melt the snow and ice. Especially if the ice or snow is really thick.
It sure can work though if conditions are not too bad.
Don't you have to get the DC voltage higher then the Vmp of the panel array ? Or will any amount of voltage work ?
Quote from: mike90045 on January 09, 2020, 08:48:49 PM
Don't you have to get the DC voltage higher then the Vmp of the panel array ? Or will any amount of voltage work ?
You have to raise the voltage every so slightly than the Voc. Remember that a solar panel is just an array of diodes in series.
Soon as your external power supply (or charge controller) drives the panels over the Voc, those diodes start conducting and start dissipating heat like a space heater. It's not an on or off kind of thing as I remember so there is somewhat of a I-V knee.
You definitely want to limit the current to below the series fuse rating though. That is what limits the snow melting mode functionality and temperature rise of the panels to melt the snow if it is too cold or too much ice/snow on the panels.