Solar power

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How we used solar power to become more self sufficient in caravaning

At the beginning of 2004 we needed a caravan to put on a piece of land we had just bought in Burgundy, France. As there was no water or electric connected to the land so we needed to be completely self sufficient. The only source of water was from the old well across the road (pictured). This was where I filled our aquaroll.

I worked out that we would have a power requirement of about 2.5 kilowatts so I bought a 2.5kva generator which had a 240v output for the caravan and also a 12 volt and 110 volt output for running my power tools.

As a backup source of mains power I bought a 2.5kva inverter and two new 110 amp leisure batteries (pictured) The generator supplied 240v to the existing 240v sockets in the caravan, whilst the invertor supplied 240v to seperate 240v sockets I had added in the form of extension leads and sockets velcroed to the wall of the caravan.

Whilst the generator would charge the batteries when it was running and the car would charge them while towing, I wanted an alternative, more eco-friendly method of charging. Solar power was the obvious choice so I bought a 40w solar panel and charge regulator. I fitted a cigar lighter type socket to the front of the caravan which has a rubber cover to keep out the rain when towing. This was connected to the input of the charge regulator (pictured below to the right. It's the black unit under the 4 way plug sockets).

The charge regulator is to stop overcharging and over discharging of the leisure batteries and to stop the panel discharging the batteries at night. The regulator has an input, to which the solar panel is connected, an output to charge the batteries and a controlled 12v output to power accessories.

I connected 15m of flex to the solar panel with a cigar lighter plug on the end. This allowed me to place the panel in the best location to catch the sun. Actually, most of the time I placed it on the roof of the caravan.

The other advantage of the solar panel was that, while away from the caravan for long periods it would keep the batteries fully charged. This meant that returning to the caravan after 3 months we instantly had both 12v and 240v (via the invertor) power when we arrived. I bought my panel from Sunshine solar who were the cheapest place I managed to find in the UK. Click here to visit Sunshine Solar Limited.

So we were pretty much self sufficient by now. The only thing that let us down in any way was the shower. It would only give about a two minute hot shower before the water ran cold so I decided to try and pre heat the water before it went into the Cascade 2 water heater using solar energy. I found some highly flexible black water hose and passed each end through some holes drilled in the floor of the caravan near the heater. The hose was laid out in the sun and then connected in line with the input to the water heater. When the first end was connected I ran the water pump to purge the air from the pipe then connected the second end. It was now August and so after just 15 mins in the sun the hose was already quite warm. The result was that we were both now able to have comfortably warm showers of 5-10 minutes each. A definite improvement! The only problem I had was with the hose connection which, because of the type of hose, it leaked a little at the connections. I will have to experiment a bit more to find a more efficient system of connection and perhaps develop a proper, lightweight solar panel. I will keep you posted on my progress.

One thing I realised early on was that being successfully self sufficient was not just about creating your own sustainable energy but also about using it as slowly and wisely as possible. With this in mind I changed all the conventional filament bulbs in the caravan over to LED (light emmiting diode) bulbs. These have the benefit of using far less energy than conventional bulbs and have a life of about 20,000 hours!

21/11/06.

After having lost the two original 120ah batteries due to them going into deep discharge they have now been replaced with two new ones. The problem had been caused by the old original battery charger fitted to the caravan as standard. This old charger only put out about 4 amps, totally unsuitable for two huge batteries. This has now been replaced with a 20 amp intelligent charger. I now also keep the solar panel connected and hung in the back window of the caravan which faces south. This should stop the new batteries falling into deep discharge over the winter months - fingers crossed!

Do you have an ongoing Solar power project you would like to tell us about? If so, send an email with pictures to solar@gps4touring.com and I'll put it on this site.