As with all electrical stuff the cooler it is the better it works, so make sure there is a gap underneath the solar panel for air flow when mounting them on the roof

I have two 80 watt panels to fit to the roof of the bus, and each panel puts out 5 amps when the sun is shining clear and uninterrupted on them, multiply amps by volts and you have 60 watts x2 panels, In general it will produce 70% of its rated power as it is not fixed to face north

For capacity, or amount of power on hand,, multiply both volts and amp hours to get the wattage, =12v X100 amp=1200 watts per hour battery,

Dont take out more than 30% from the batteries, before charging them

If you have a TV which needs 75 watts, (you can see from the label on the back its power consumption, a radio that needs 10 watts, plus a speaker system as an extra that needs 30w, a computer that needs 30w,  and a fridge that needs 60w then you add them all up for a total wattage of what you need and we have a total of them all =205 watts per hour

Therefore I dont need the  backup, with those figures
Howerver the sun doesnt always shine bright and clear, if a week went by with grey clouds,   7 days x usage of 205=1435, I am immediatly in the red,
Another panel at $700 or the use of a generator (cost of Petrol ongoing)  will be required,

Another panel, or the Generator,?? remembering that there is no inverter which has its own losses, therefore no 240v

Or I can reduce my consumption,---------------  we are all different power users
you work it out from here.

Very interesting Terrific read that....

Solar's simple all right. I simply can't afford it! Cheers, Tony

Hi Mike I may be on the dumb side. you need to fill in the gaps for me ..... 2 x 60 x70% =84 how does 12 x 100 fit (battery?) How did you calculate weekly usage as -205 per day ? Where does the 30% come in. If we had some additional information hopefully a few dunderheads like myself might be able to make the connection and actually learn something ! Mike

G/day Mike Somewhere I have writ it wrong, loss per panel is on average of 70% Therefore on an 80w panel it comes to 58w x 2 panels = 116w coming in per hour, 205w is the total of all the appliances that I use in that hour, so I am short by 205-116 = 89w that comes to a bit over one panel short, so I reduce my consumption, or start the genny keep up the questions you and I will get there one day

ok -I'm getting there ! Yep makes sense to do the numbers. Here's a question though. What if you have wireless broadband and need 240 v . My telstra one doesn't show the wattage but I guess it will be low consumption. Could you say buy a small invertor -maybe say 2-300 watts for this purpose ? as well as using solar to recharge and run other gear ?

Mike sure you can, I have an 800 watt inverter I bought from dick smith for about 200 bucks a long time ago, which plugged into my anderson plug on the car, that was in the camper and I used it as a bckup for the cd player I occasionally used, running a 240v lead into the tent As an alternative you can buy a lead that fits your cig lighter in the car, like I do, your laptop usually is about 35 watts and the car, will charge her up, this is wureless I am on now if you need anything in the way of converters or inverters ask the people in dick smith, they have the answers

Thanks Mike that is excellent info for me All the best and safe travels

Hi there, it seems you know solar so am wondering can you help me with our solar.  We bought our caravan second hand and it came with solar but no wiring plans.  Has been working ok until recently, now has stopped charging to the regular/batteries.  What are the the things we should do and how is the wiring done from the panel to the regularor in the front locker any help please,    rgds Gitsho