Solar power calculators

[Romana-S]

Currently my van has 3 x 64 watt unisolar panels, and a 80watt panel. This is 272 watts of solar power. That was enough for the occasional camping trip, but for full time on board living it is a little low. I have a 12 volt fridge, and a laptop, tv, LED lights and so on. <br>I am thinking of upgrading this, as I have 300 w of 100w panels that were origionally intended for my big bus. I could replace 2 on the 64w solar panels with the 300 w of panels. That would bring my wattage uo to 444 volts. Or I could replace all 3 of the unisolar panels with 500 watts of 100w panels for a total of 580 watts.<br>Why so many watts? well I want to be able to run my 12/240v 10 litre hot water service and a small 12 volt heater from the van's power system. <br>What I am looking for is an online or downlodable power usage calculator.<br>Down here in Australia electricity costs are going through the roof, 27 cents per kilowatt hour already and more going up. With my 3 montyh power bill being $239 and me being a very conservative power user, it will soon be cheaper gto just buy panels instead of power.<br>

 

[blars]

I think you'll find heating or cooling (other than maybe a little cooking) is impractical with a solar setup.&nbsp; I'm using a little over 1kwh/day, and my 450 watt solar setup can maybe produce twice that on a sunny winter day.<br><br><br>

 

[Romana-S]

Yeah, most often that would be the case. But I live in Australia, and we get a lot more sunlight hours than most of the USA. So a 580 watt system, getting even the short 5 hours of sunlight on the worst winter's day, each 100w panel produces 5.25 wats of power. I'll ignore the 80 watt panel as a way of counting in system losses. <br><br>So that would be 5.25 AH x 5 panels x 5 hours. Or 131 AH of power. On a good day it would be 200 AH of power. <br><br>The Duetto hot water service while using 12 volts consumes 25 Amps per hour. Yes, that is a lot. But it heats up the 10 litres to 37 C in that hour (actually around 48 minutes)&nbsp; so then it switches it self off, only heating up periodically as the water cools. I plan on using gas for showers, and the Duetto for washing up, and hand washes of clothing.<br><br>I figure this is possible with a massive 580 watt array easily.<br>Mind you with the 12 volt fridge and other loads using power as well, the power draw will be more than 25 AH, but I'd easily have 100 AH a day to play with. <br>