A potential client today said that her husband had been dissuaded from going solar by two electrical engineers who told him that he wouldn’t save any money. Once I’d recovered from the shock, I realised that I actually had to respond to this misconception. Being an electrical engineer myself, I had to wonder how two of my colleagues could get it so wrong.

The reasoning that they used to persuade this person went as follows -  you’ll drain your geyser by showering in the evening and will have to use electricity to reheat it for the morning.  So unless you radically change your habits, for example by only showering once a day at a specific time,  you won’t really see any savings.

I guess there is some small degree of truth to this. If you manage to drain your geyser of hot water every evening, you will have to use electricity to reheat it if you want hot water again first thing in the morning. The trick here is to install the right size of geyser so that you don’t end up draining it every evening. And the more information you can provide to your solar company about your water usage habits, the more likely it is that they will provide you with the right size geyser.

But even if you are draining the geyser every evening, and then again in the morning, at the very least you will be using solar to reheat the geyser during the day. So compared to before you had solar, when you had to use electricity to heat water day and night, at least now you’re only using electricity at night. You can’t tell me that’s not a saving!

And perhaps it is also true that some kind of behaviour change is called for. If you were draining a full geyser every evening and then using hot water again in the morning, it might be time to think about the amount of energy you’re using. We see installing a solar geyser as a positive in this respect – it often gets families thinking more carefully about the energy they’re using and monitoring it more closely.

Finally, I have to bring in the example of clients we have who now switch off their geysers for approximately eight months of the year. Of course, they can do this because their solar systems are correctly sized. Still, you can’t tell me that they’re not saving a heap of money during those eight months!

Comments welcome – perhaps there’s something I’m missing?

Ed.

Solar Science is a supplier and installer of solar water heating systems to the greater Cape Town area. Get in touch if you’re interested in a free quote.