The most energy hungry appliance in the average home or hospitality building is the electric geyser. According to Eskom’s research, electric geysers account for 43% of the average household’s electricity consumption. It’s therefore a no-brainer that this is the logical starting point of any energy efficiency drive. A correctly sized solar water heater should save at least 80% of your water heating costs, so that’s about a 35% saving off your total electricity bill on average.
Solar water heaters (SWH) come in all shapes and sizes and are definitely not a one-size-fits-all product. There are high pressure or non-pressure units, close-coupled or split units, direct or indirect units, thermosyphon or pumped units, evacuated tube or flat plate units, and so the list goes on.
The key to a successful SWH installation that gives you the electrical savings that it should is to select the correct product configuration and size for the specific application. This is why an experienced installer such as Solar Focus should be consulted when deciding on which technology to invest in.
Most SWH on the South African market incorporate an electric backup element which ensures that you have hot water even in cloudy conditions when the solar absorption is limited. But a correctly sized SWH should seldom need the intervention of the backup element.
Done correctly, a SWH should reduce your water heating costs by about 80% or more. But the biggest mistake that many people make when installing a SWH is to skimp on the storage capacity of the SWH in order to get the initial cost down, resulting in the backup element being called into service too often and the electrical savings being less than expected.
At Solar Focus, we prefer to meet with our clients at their homes or establishments to do a full assessment of the hot water requirements and the site conditions before making a recommendation. We look at factors such as the roof orientation and structure, shading from neighbouring trees or buildings, water quality and the hot water usage patterns of the family or guests. Based on our assessment, we will recommend the most appropriate product type and size that will offer the electrical savings that should be achieved at the most cost effective price possible.
Solar Focus has installed many hundreds of domestic SWH over the years and a few larger systems for commercial operations. We are capable of installing anything from a simple 110ℓ non-pressure system as used on government housing projects to large commercial systems of 20 000ℓ or more.
Solar water heating can also be used for industrial processes that require hot water, or even steam.
Solar Focus sources SWH from a number of local manufacturers, all of which have the SABS Mark. Occasionally, we will source an imported offering if there is a real advantage in doing so, but we prefer wherever possible to support our local manufacturers.
Some of the brand names that we are familiar with include:
KwikSol (manufactured by Kwikot)
SolarTherm (Manufactured by Duratherm)
Nobel Solar (imported)