Advantages of solar heating:

• South Africa has very high solar irradiation, so using solar power makes sense.
• Other than buying the technology, solar will save you money. You have to look at buying solar water heating systems like looking at an investment.
• Heating water with solar is free, so there is a reduction in monthly electricity bills.
• By using solar water heating, your household is much less vulnerable to electricity price increases.
• Financial rebates from the Eskom.

Using solar energy contributes to saving 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 or 6kg of sulphur dioxide, which contributes to acid rain, or taking 1.5 cars of the road.

Solar water heaters consist of three parts:

• Storage Tank – this is where the hot water is kept.
• Collector – this is the collector that transfers the suns energy into heat to make hot water.
• Booster – the booster (Electrical element) is used to ensure that hot water is available during overcast days and at night. This is placed inside tank like a normal electrical geyser.

The collector can either heat water directly, which is called an open (direct) system, or indirectly, called a closed (indirect) system. Direct systems are generally used where there is absolutely no chance of frost, outside temperatures don’t go below zero, and the water quality is not a problem at all. In other words, you most probably want an indirect system. An Indirect system is a system where the water used does not circulate through the collector panels. The heat transfer fluid used in the collector panels is heated, and that heat is then transferred indirectly, i.e. with-out coming into contact with the water that will be used, through the heat exchange jacket.

Solar water heaters work in one of three ways:

• Thermosyphon action occurs when the heat exchange fluid which is heated in the collectors expands, becoming lighter, and allowing colder, heavier heat exchanging fluid to fall to the bottom of the collector. The cold fluid pushes the hotter, lighter fluid back up into the storage tank, where the heat is indirectly transferred to the water held in the tank through a heat exchanging jacket.
• Vacuum or evacuated tube collectors use two glass tubes, in between which a vacuum has been created. Solar irradiation heats an absorbent material on the inner glass tube, which is transferred to the heat conveyance system inside the inner glass tube. This conveyance in the inner glass tube is an evaporating-condensing liquid that evaporates in the collector tubes, and then transfers heat through condensation to the cold water in a manifold. The hot water is then stored in the storage tank.
• Pumping water/agent through the collector to be heated, and then heating the water in the tank.
  

That is entirely up to you, but here is some information to help you decide:

The collectors should ideally always be angled facing north to catch the most sun.

Watch-out for systems that have the following drawbacks:

• Storage tanks made with products that can contaminate your water supply, such as tanks that can rust.
• Make sure that the components can be disposed of safely. Some collector types are made with heavy metals or toxic compounds.
• Ensure that your warranty is not only valid for a year but at least 5 years. Insist on a warranty on the installation itself for at least a year.
• The usual precautions such as ensuring you get a reliable product, from a reliable supplier with good experience.

Currently we support two different system types

150L TS Indirect

Imported, closed/indirect thermosyphon system, designed in Germany. A closed/indirect system is one with 2 loops, where one uses anti-corrosion and anti-freeze solution, which protects the collector and tank. The household water in the second loop is then indirectly heated. Should the water temperature drop below a certain setting, the system will automatically switch over to electricity to increase the temperature to the desired setting.

This system can save up to 80% of water heating costs.

Our system carries the SABS mark of approval, and qualifies for an Eskom rebate of R 5 615 which will be paid to you, the customer, directly. The system comprises a 180 litre tank (3-4 people) which must be mounted above the collector. The collector is covered by 4 mm toughened glass.

This system can be mounted either on a pitched or flat roof.

300L TS Indirect

The system comprises a 300 litre tank (servicing 5-8 occupants), which must be mounted above the collectors. The collector is covered by 4 mm toughened glass. This system can be mounted either on a pitched or flat roof. Imported, closed/indirect thermosyphon system, designed in Germany.

A closed/indirect system is one with 2 loops, where one uses anti-corrosion and anti-freeze solution, which protects the collector and tank. The household water in the second loop is then indirectly heated. Should the water temperature drop below a certain setting, the system will automatically switch over to electricity to increase the temperature to the desired setting.

This system can save up to 80% of water heating costs.

A system with a large inverter will easily cope with a kettle. A kettle does not consume a large amount of energy, but uses a high amount of power over a short time. An 810 w panel generates enough energy to boil a full kettle 8 times a day.

An energy efficient fridge uses as little as 700w.h/day per day while a non-efficient fridge can use up to 3500w.h/day.

Most appliance stores have A or A+ energy efficient fridges.

80-100W (compared to 180-350W)

Yes, a partial off-grid system would cope with some appliances and the system can expand at the pace of your choice.

A magnetic ballast single tube fluorescent light can use 100-120W. The magnetic ballast uses almost the same amount of power as the light.

Batteries are the heart of any island system:

They supply power in between alternative energy generation periods.

Battery sizing is a very important aspect of any island system. If undersized the batteries would not reach design life. Batteries are designed for a set number of cycles.

There are various types of Deep Cycle Batteries. The most basic 12V lead acid batteries will last anything between 120-180 full cycles. More advances 12V lead acid batteries will last up to 240 full cycles, while gel and AGM can last up to 600 cycles. Flooded tubular 2V cells can last up to 1200 cycles at 80% cycles, which can last up to 25 years if sized correctly.