The 1.5. This is a crappy place for solar. 1.5 hours of insolation a day sometimes.
If I need 5200WH, sometimes I only have 1.5 hours to get it.
The 17 and 12 thing. 12V panels make the max power at 17V.
Say a panel is rated for 17W. Meaning it makes 1A.
Using that 1A it made means using the 1A at 12V.
If it makes 17W, you get to use 12W.
If I need 12W to use, I need 17W of panel.
If I need to use 5200WH/D, I have 1.5H to get it.
To get 5200WH/D, I need 5000 rated watts of solar panel. Like I said, this is a crappy place for solar.
ie: I need 18W for 1 hour every day. That means I need 1.5A of 12V power for 1 hour, meaning 18WH.
To get it takes a 17W (1A) panel, putting 1A into a 12V battery, for my 1.5 hours every day.
The 20% thing. Batteries are not perfect. Just because I put 1A for 1 hour (1AH) into a battery, does not mean I can use 1A for 1 hour.
It would be easier to think in amp-hours, instead of watt-hours.
If you need 10A for 1 hour to use, then you need 10A for 1 hour to supply it.
If you need 1A at 120V for 1 hour, you need 10A of 12V for 1 hour. (120V:12V = 10:1)
It will be a lot easier to wade through the math.
Then add 20% to hopefully cover inefficiencies. 5200W x 120% = 6240W.
A good plan will have enough battery to supply the load for around 15 days of load without any charging at all. Depends on who you ask or where you look.
The 5200WH is 433AH at 12V per day. Add 20% (because that is what I like to do). 15 days is 7800AH of 12V battery.
Using the common 6V golf cart battery means 72 batteries, at round-about 65 pounds each, for about 4700 pounds of batteries.
Those trailer better be full of money!
Perfectly clear? ;-)
G-