Going "Solar Panel" instead of "Power Generator"

After much research it has become clear that to keep my house battery up and well charged without having to resort to 240V and the local Trailer Parks, the way to achieve this was to go Solar. At 45W my refrigerator is the main power consumer, running for around 12-16 hours each day. The other on-board electrical devices are lights at 800mW for about 3 hours each day, my Laptop at 65W for about 2 hours a day and the odd re-charge of my Mobile phone.

I have certainly looked at using a generator instead but the really good ones which produce consistent 240V at exactly 50Hz are very costly and also require the carriage of extra fuel apart from a large and cumbersome extra piece of equipment. Generators are often frowned upon by fellow travelers because of noise and environmental pollution. Yes, it does produce more power than Solar on the roof of my van but that extra on power is not needed for my purposes. Solar was the obvious choice instead!

Solar panels work best when facing directly at the sun at an angle of about 90 degrees. This is particularly important at higher latitudes like the southern parts of Australia or Tasmania, whereas in the northern parts of the country the angle of sunlight ist mostly overhead for most of the year, tracking the sun becomes less important. There is however technology that will regulate the power available power from the Solar cell which is called "Maximum Power Point Tracking", here an excerpt from an article taken from the CMCA website...



Maximum Power Point Tracking
This is a totally different technology that, like tracking, is intended to increase a solar modules output. A typical solar module produces maximum power (volts times amps) around 17.2 volts, but as a battery requires anywhere from 14.4-14.7 or so volts to fully charge, that part between the solar output and the battery's need is normally lost. The MPPT unit juggles the volts and amps to optimise watts thus recovering some part of that lost area. The technology is particularly effective where (a) the battery is low in charge, and (b) during the early and late hours of the day. These devices are typically claimed to save 25-30%. General experience with a large MPPT unit is that the gain varies from 12.5-17.5%. This is certainly enough to justify its use.

The hard part of this exercise is to setup the wiring in the van. To keep all the wires invisible requires a lot of "gymnastics" and fiddling in order to get all the cables under cover. I am glad to report that this has been done and the MPPT Regulator has been installed as well. An extremely important consideration is the diameter of all the cables as we are dealing with DC power where a lot is lost over the length of the cable. For my installation it would be sufficient to use 2.5mm wires but I chose 4mm instead to be on the safe side. None of the cables are connected to anything yet but I got a really good deal on a Solar Panel yesterday, so toay-is-the-day when I will finalise my Solar Installation and get it up and running. I will report on the performance shortly.