Hi thompkinz, Kev,
I'm also planning my future RV's solar setup, so I will be watching this topic attentively. I've read up a lot on solar and I think I have some understanding of how it all works, but as they say, there's no substitute for experience...
That said, I think I can contribute a little with some things I do have some experience with:
thompkinz said:
Hey there folks! I know there's a lot of posts about how much solar to use but I've tried to narrow my usage down to the items I'll need to help find a better answer. I'm trying to find a kit that has every thing I need for simplicitys sake. So here's the items and wattage I'll be using and approximate usage times. So let me know if you see any issues. I know the printer uses a ton of power but since it's going to be a part of our mobile business, it can't really be substituted.
Lights for few hours 20 watt 4 hours
Brother hl3140 660 watt 2 hours max
2 Laptops 20 watts 2 hours
Iphone charger 5 wattage 3 hours
Fridge 500 all day.
Please excuse me, thompkinz, but some of your numbers seem a bit off: the laser printer can use 500W, but in my experience (with HP LaserJets) this only happens when its fusor turns on. Will it be on during the entire 2h?
Ditto for the fridge: only when the compressor kicks in will it consume 500W. Unless you leave its door open, the compressor should be off most of the time.
On the other hand, 20W for a laptop seems a bit too low, unless it's a very flimsy one (like a chromebook). In my experience, even a modest laptop consumes something more like 50W.
My experience with those numbers come from having recently completed my own energy audit: I got one of these:
P3 P4400 Kill A Watt Electricity Usage Monitor and plugged it between each of my appliances and its wall socket, then returned 24h later to read its Wh measurement and put it in a spreadsheet. That gave me solid, real numbers to work with.
I recommend you do the same, a solar setup costs a lot of money and it can be much more expensive to "save" on the initial audit and end up getting a less than ideal setup.
Cheers,
--
Vall.