A few months back, I donated my 16.5 ft Jayco poptop caravan to an organisation which is using it as temporary accommodation following recent bushfires.
An elderly person is apparently using it now and I don't know where it is currently parked. Being in a burnt out area, it is likely that there is no power or water available. This got me thinking...
What amount of solar panels would be required to run the van with no external input? The van has a Heron 2.2 Aircon, which I believe would draw about 1 kW of electricity. With winter coming on (already here?), the heater will almost certainly be used. From memory, the A/C compressor was not used in heating mode, so the electrical demand would be the full output ie about 2 kW. Therefore the heating load would be about 24 kWh, assuming 12 hrs operation as a heater. The fridge pulls about 120 watts, which could be ignored for now as part of the energy consumption. Same with the lights...
So they would need a battery to supply about 25 kWh of energy. Assuming 5 hrs of productive sunlight per day, this means a 5 kW set of panels and inverter. Even 5 kW of panels would struggle to provide 25 kWh, but we are talking compromises here - the heater would have to run less hours.
5 kW of solar panels would occupy more than the roof area of the caravan, so a separate frame would be required. I am OK so far, but am out of my depth regarding battery storage. Does anyone on this forum have experience in setting up an off-grid installation which would capably run the caravan's electrical load?
-- Edited by erad on Monday 20th of April 2026 02:33:10 PM
If you install a 2.5kW split system air conditioner, they are really efficient. Look up the rated input power.
Cooking is high load, but it is only for short periods. Like making tea etc.
Domestic fridges are very efficient.
The biggest issue is not the day to day power generation, storage & consumption if weather is ideal. Also if you are closer to the equator that helps because the sun is higher.
Inclement weather, further south, any form of shadowing. A week of overcast skies & you will need a far larger set-up & more than likely some other form of input to charge the batteries.
Personally I would be looking for a week of battery power in winter when solar panels are working at a very low percentage of their rated output. They really struggle at the wrong time of year.
In Sydney last year we had weeks on end of rain. Solar panels were not doing much.
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