Solar Water heaters - FAQ

Why should you look at solar heating in the first place?

Okay, so you aren’t that sure about it – here are the advantages of solar heating:

• South Africa has very high solar irradiation, so using solar power makes sense.
• Other than buying the technology, solar can save you money.
• Heating water with solar is free, so there is a reduction in monthly electricity bills.
• Less vulnerable to electricity price increases
• Financial rebates from the Eskom & the Government
• Using solar energy contributes to the environment:
• Using solar energy means less consumption of natural gas and coal
• By more people converting to renewable energies, less and smaller new power plants will be needed, thus reducing the potential damage done by these plants.
• Replacing your geyser with a solar water heater can annually save up to 3.5 tonnes of CO2 emissions and 6kg of sulphur dioxide, which contributes to acid rain.

What does a system consist of?

Solar water heaters consist of three parts:

• Storage Tank – this is where the hot water is kept.
• Collector – this is where the sun is used to make water hot.
• Booster – the booster is used to ensure that hot water is available during overcast days and at night. Our system has an electrical booster, but a gas booster for off-grid applications is also available.

How does the system work? Thermo siphon action occurs when the agent which is heated in the collectors expands, becoming lighter, allowing colder, heavier agent to fall to the bottom of the collector. The cold agent pushes the hotter, lighter agent back up into the storage tank, where the heat is indirectly transferred to the water held in the tank.

What is the difference between an indirect (closed) and direct (open) system? With the indirect system, the liquid heated in the collector is NOT the household water, whereas with an open system, the household water flows through the collector. The two advantages of the closed or indirect system is firstly that the liquid can contain antifreeze, preventing the liquid from freezing in the collector and bursting pipes and secondly there is no lime scale build-up from impurities on the municipal water.

What prevents hail from harming the system? The collector is cover by tempered glass, but should the glass break, it will merely reduce the efficiency of the system; you will not be with-out hot water!

What are the benefits of this system?

• Reduction of electricity bill
• Reduction of carbon imprint, which is good for the environment
• As the system is an indirect system, no chance of freezing and pipe damage
• None of the components are harmful to people, animals or the environment
• Tempered glass cover, which is hail resistant
• Adds value to your home
• Possible rebates from Eskom

What should be done when going away?

If you are going away for longer than a week, the element/electrical booster should be switched off, and ideally the collector covered.

Frequently asked questions – Photovoltaic Systems

Do you sell all the components of the system?

Yes, we also sell two solar home kits:

• 220 Wp, which comes with two PV panels, two batteries, charge controller and pure sine wave inverter for about R35 000,00
• 440 Wp, which comes with four PV panels, four batteries, charge controller and pure sine wave inverter for about R50 000,00

What does such a system typically cost?

As the panels are fully imported, the price is highly dependant on the exchange rate, but currently the costs for a full system are about R100 000,00 per kWp.

Why buy a solar water heating system

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