The founder and MD of long established solar water heating (SWH) company Solar Beam, Graham Mundy, has warned consumers to do their homework before investing in a home SWH system, following a number of systems going bust after extreme weather conditions experienced in Gauteng this winter.

Consumer interest in SWH has soared in recent years as a result of climbing electricity prices and a rebate that State-owned power utility Eskom was offering to homes that buy solar systems.

Mundy noted that where there were once only nine companies supplying SWH solutions in South Africa, there were now more than 400.

"This has left the SWH solutions market rife with confusion because a number of businesses have moved into this market to take advantage of its growth, without the experience or technology needed to provide a sound solution to business and residential customers."

He said that most consumers were unaware of the differences between 'indirect' and 'direct' solar heating systems, resulting in many being duped into buying the wrong system for their homes.

An indirect system has been protected from freeze damage by an anti-freeze solution in the solar panels and a heat exchanger in the solar geyser. The sun heats the anti-freeze solution in the panels and the heat exchanger transfers that heat into the water of the solar geyser. This will ensure that the panels do not freeze up and burst during winter.

Mundy said that consumers who lived in parts of the country where the outside temperature drops below 3 °C must install indirect SWH systems in their homes.

Direct SWH systems could be installed in areas without frost and where temperatures remain above 3 °C .

In direct systems, water is heated in the solar panels and rises directly into the solar geyser. "These systems are slightly more efficient than the indirect systems," says Mundy.

Further, Mundy said that consumers should take caution when choosing a preferred supplier without the proper certification and experience.

"Make sure that the company you choose has been in business longer than its guarantee and ask for references, preferably from a client who has had a system for five years or more.

"Also, ensure that your solar system of choice has the full South African Bureau of Standards (SABS) mark of approval. Do not confuse this baseline requirement with an SABS compliancy certificate, which is a once-off test on one item and does not guarantee continued quality and check that the SABS mark of approval applies to the entire system and not just to one or two components."

He further cautioned consumers to be wary of imported products, as foreign accolades were often times not applicable to the harsh weather conditions in South Africa. "Many companies are trying to sell solutions based on glass tubes into the market, which are a poor fit with local conditions. Flat-plate technology is a better fit for South African weather conditions."

In addition, Mundy said that even though the cost-savings approach of ‘retrofitted' solutions might seem attractive, the quality and performance were not always up to standard.

A retrofitted solution is when a solar panel is connected to an electric geyser. Mundy explained that one of reasons for its underperformance was that an electric geyser would cycle its contents electrically in around three hours, while a solar geyser needed to store 24 hours of hot water for the whole family's daily needs. "This water will be heated by the sun over a six-hour period, which means that the solar geyser must be bigger and have better insulation than your existing geyser."

Mundy said that with the ongoing electricity supply crisis in the country, everyone had a part to play in conserving energy, saying that installing a good SWH was an excellent way to do just that.

However, he warned that it was important for consumers to do their homework and to choose a solar heating system that was able to provide ample hot water and deliver on durability. "Currently, the consumer is paying the price for the proliferation of suppliers who lack the necessary experience," he concluded.