Generally, the feeling regarding solar water heaters is that they are far more environmentally friendly than any current alternative. If you want environmentally hot water, solar is the way to go.
Or is it? Just because it’s taken as gospel that solar is more environmentally friendly than other ways of heating water, doesn’t necessarily mean it is.
Let’s look at the facts.
The costs of manufacturing solar
When discussing solar energy and its attendant impact on the environment, this is the one thing that’s overlooked more than any other: sure, using solar in the home is almost certainly better for the environment, but what about the environmental costs of making solar geysers?
The environmental cost of manufacturing solar can really be split into several distinct subsections, each of which has its own unique impact:
• The manufacturing process itself
• Material transportation
However, for our purposes we’ll talk about the process as a whole.
The potential environmental problems in solar manufacturing lies in the materials used and the energy needed.
The materials used in manufacturing are often hazardous. These require special care in the process itself, as well as proper care for disposal. However, with the right precautions these materials have no undue effect on the environment.
The energy used in manufacturing solar comes into play both in the process itself, where industrial machinery is used, as well as in the fuel needed to transport materials and products.
Obviously, if the energy for the manufacturing process is taken from the grid, it has an impact on the environment – most electricity in South Africa is still produced by coal.
Luckily, this is offset by the long life of solar water heaters: often up to 20 years.
What this essentially means is that the environmental cost of solar manufacturing is spread over the entire life of the solar water heater (as there is no environmental cost once the heater is installed), so that the power you’re getting is far more sustainable than electrical alternatives.
The costs at home
This is far simpler to quantify: the environmental cost of solar heating once the unit is installed is, quite frankly, negligible.
Any impact caused by heating water with the backup element in a solar water heater when the sunrays are not sufficient to heat the water i.e. overcast days or at night, is far less than heating water in