I actually plan to run some more components on solar power. As I have some devices running 24/7, I would like to have them at least to run green. But I am still unsure about the size of my battery backups and panel sizes. What would you recomment in order to run 100W device 24/7 on solar. Considering winter with very few sun hours per day, my initial plan was to have about 400W of panels. probably adding a wind turbine for windy not so sunny days. And what battery capacity would you recommend on such a setup. The whole setup is able to run on 12V, so no lost on DC-AC conversion.
My working for that would start along the lines of 100W at 12V requires 8.5A (rounded up to the nearest half amp). For 24 Hours worth of battery you would need 204Ah worth of 12V cells (that's a few car batteries worth).
For 24/7 operation you'll need to have enough solar capacity to run your devices and charge the batteries. In winter there might be 8 hours of reasonable light and 16 hours when you need to run from battery, meaning you'll likely need 300W output from the panels.
Also in winter you probably wont get the full output from the panels, based on a little of it experience you might only get 10% of the panels output on an overcast winter day (maybe even less with really thick cloud cover).
At that power usage you might benefit from running the solar output and battery systems at a higher voltage dropping down to 12V near the point of use (100W as 12V means over 8A, that can mean a large voltage drop in the cable unless you're running very large wires, running at 48V means just over 2A so smaller cables for a similar voltage drop)
Thanks for the feedback, so with 400W of panels with additional wind turbine of 400-500W it should be fine to run 100W 24/7.
As for the cables, I should be fine. I still have some 4mm2 cables around which can take easily 60A.
Batterie capacity will be slightly higher as you suggested to avoid deep discharge in case of bad weather conditions. Will probably scale the batteries to last several days.
I will think about your suggestion to raise the voltage to 24V, but as most device are able to run on 12V, I need to see if it benefits the whole setup when I raise the voltage.