The prototype on the deck
Experimentation is the mother of invention, to paraphrase an old saying.
I’ve been experimenting (successfully) with a small solar panel to determine the feasibility of supplementing the charging of my 12 volt batteries by a petrol-fuelled generator.
In spite of days of continuous overcast skies, fog and an absence of direct sunlight, I have been pleasantly surprised at how effective the experiment has been in providing more than enough energy for the big shortwave radio and the LED lights. With petrol now at $2.80 a litre it is a worthwhile saving. The alternative option of connecting to the mains supply would be an initial capital contribution and connection charge of some $11,600 and a monthly charge and unit cost of 88 cents a kilowatt.
Fine, I know that this has been done in summer time and that in winter the skies will be even duller. But the panel I have been using is only 20 watts and I have in mind installing two and possibly three much larger 180 watt panels that would be sufficient to power an inverter and run a small 240 volt fridge/freezer, as well as the lights and radio, even in winter. I’ve lived without a fridge now for several years without too much loss of convenience, but it would be good to have a freezer again.
So that I could get as much information as possible, I alternated the solar charging of two batteries with their use, and tested them each morning. I also did a voltage check of the charging rate from the panel at the peak of light in early afternoon.
My other unknown was the loss of voltage between the panel over the distance from the mounting on the deck to underneath the house where I have the main storage battery and the switchboard. By running a heavy duty cable and testing the power at each end I was pleasantly surprised to find the voltage drop was insignificant and, if I proceed to the next stage, I will be able to mount the panels above the deck and put the new deep cycle batteries and inverter in the car port at ground level.
I feel a new sense of empowerment!
- The prototype on the deck
Old Man's Folly 