I had a solar geyser installed in July last year, and looked forward to its paying for itself over about 3 years, according to the figures provided to me. I’ve had many enquiries about solar heating since, so I did a few quick sums to work out exactly how much the solar system is saving me in electricity bills each month.
My average electricity bill from January to July last year (seven months, including two winter months) was R565.
My average electricity bill from August last year to February this year (also seven months, and also including two winter months) was R400.
That’s a saving of R165 per month or about 30%.
The cost of the system, less a rebate from Eskom (which was only paid in December, 5 months after installation and all the paperwork had been submitted, and after repeated enquiries), came to about R10 000.
So at the moment it seems that the real payback time is about 60 months or 5 years.
It’s probably worth mentioning (and can be seen by my average bills) that we as a household use very little electricity – we don’t have power-hungry appliances like heaters, air-conditioners or tumble-dryers – and I’d think that in a home where the general electricity consumption is higher and there’s more hot-water demand, the savings would be more marked.
Also, because of the vagaries of the weather in the Western Cape (with both summers and winters varying in their degrees of harshness), a more accurate reflection of any savings would be the average electricity consumption of the full year before installation (July 2010 to July 2011) and after (August 2011 to August 2012).
I’ll repeat the exercise in September.