The decision to install a solar power system in your home shouldn’t be taken lightly. It’s important that you are comfortable with every step of the process and know precisely how the solar panels and geysers are used to save energy and money.

There are several questions you need to ask before you decide on a specific system for your house. We’ve assembled some of the most commonly asked questions with their answers below:

1) What is solar water heating?

Solar water heating is a system for heating water using energy from the sun. Solar power is collected by solar panels, which are connected by pipes to a hot water storage device such as a hot water geyser.

2) What are the benefits of installing a Kayema solar power system in my home?

Solar power helps save energy and water heating costs by reducing the amount of electricity or gas used by houses to heat water. By using sunlight to heat water instead of fossil fuels, fewer pollutants are introduced into the environment. Solar power is not affected by electricity shortages and does not stop providing hot water for your home during load shedding.

3) How much of my total hot water requirements can a Kayema solar water heater provide?

A solar water heater can provide between 50 and 90 per cent of your total hot water requirements, depending on the climate and type of system.

4) By how much will my electricity consumption be reduced if I replace a conventional geyser with a solar powered system?

A standard electrical geyser uses 30 – 50 per cent of your household’s monthly electricity bill. Replacing your conventional geyser with a solar power system, including solar panels, will reduce your home’s electricity consumption by up to 70 per cent.

5) Does a Kayema home solar power system take long to install?

Once a site inspection has been conducted the installation can be completed within six hours.

6) Why do solar water heaters need to have electric backup?

All solar water heaters include electric backup to ensure hot water during the cold, dark days of winter and on those rainy days we have from time to time. The right size system will meet your family’s hot water needs and reduce your dependence on the electric backup.

7) Do I need to install a new geyser or can solar panels be added to the existing system?

Standard geysers are not designed to be used with solar panels, as they do not have sufficient inlets and their linings are often not designed to withstand the temperatures generated by solar energy. Kayema recommends clients replace their existing electric geyser with a solar one.

8) What are the basic requirements to install a solar water geyser?

You need to have enough shade-free roof space. The roof of your home also needs to be strong enough to support solar panels and the geyser. A roof carpenter will accompany the installers to the site to inspect the integrity of the roof and reinforce it where required.

Thatched roofs are often not suitable for solar ater heating systems.

9) How hot can the water get?

Kayema’s system is able to heat the water to between 55 – 65 degrees Celsius. Your bath water temperature is around 41 degrees Celsius.

10) Why is it important that a solar system be SABS approved?

Solar water heater specifications focus on three main areas: quality, performance and safety. As the payback period of solar power is very important it’s vital that the quality of solar water heaters ensure the longevity of the system. The mechanical performance tests, e.g., hail, freezing and pulsation tests are conducted to ensure that the minimum quality standards are met. The performance tests are conducted to determine how well the system works; the safety test determines if all the safety requirements are met, including electrical and mechanical safety criteria.

Besides carrying the SABS mark of approval, Kayema’s system is also approved by similar bureaus in Israel, Germany and Spain.

11) What is the difference between a flat plate and vacuum tube solar water heating system?

Flat plate and evacuated tubes refer to the two basic collector types used to absorb heat from the sun and transfer it to the water.

Flat plate collectors, such as the ones Kayema uses, consist of a dark flat-plate absorber of solar energy, a transparent cover that allows solar energy to pass through but reduces heat losses, and heat-transport fluid (anti-freeze or water) flowing through the tubes. Fluid is circulated through the tubing to transfer heat from the absorber to an insulated geyser. This may be achieved directly or through a heat exchanger.

Evacuated tube collectors are composed of multiple evacuated glass tubes each containing an absorber plate fused to a heat pipe. The heat from the hot end of the heat pipes is transferred to the transfer fluid, (water or anti-freeze). The vacuum that surrounds the outside of the tube reduces heat loss to the outside.

12) What is the difference between an indirect and direct solar water heating system?

Indirect systems use a heat transfer fluid (glycol) to move the heat from the solar collector to the tank, heating the water indirectly. Indirect systems are freeze resistant, but require minimal maintenance because the glycol may evaporate over time.

In direct systems the potable water is the heat transfer fluid, i.e., the actual water you use to shower passes through the collector. Direct systems are simple and reliable and don’t require regular servicing; however, they are susceptible to damage in sub-zero temperatures (unless they are freeze-resistant) and should be installed in frost-free areas only.

The rule of thumb is if the temperature ever drops below 4 degrees Celsius you will get frost.

13) Can I install the system myself?

It’s possible to get DIY-friendly solar panels and systems for the home, but to qualify for the Eskom rebate the system needs to be installed by an approved expert. Even though the concept of the system may look simple, many areas can be damaged if it’s not installed by a qualified tradesman.

14) How much will it cost to purchase and install a Kayema system?

Before an exact quotation can be provided, each home must be visited by an installer to see what the specific requirements are, but as a broad estimate the cost of installed systems would be as follows:

150 litre system – R17 500*

200 litre system – R21 000*

300 litre system – R29 000*

It’s important to remember that while the upfront costs of a solar water heater (including installation) are higher than electric or gas water systems, the savings on your electricity bill will compensate for this over time. The expected pay back period for a household consuming 200 litres of hot water per day is four years.

* Excludes Eskom rebate and insurance payout.

15) Are Kayema systems eligible for a rebate from Eskom?

Yes, Kayema is a participating member of the Eskom DSM programme.

16) What size solar water heater do I need?

An average person uses 50 litres of water in a 24-hour cycle. The number of people in the household X 50 gives you the correct size, e.g., four people X 50L = 200L

17) What is the system’s lifespan?

With minimal maintenance, such as the replacement of glycol anti-freeze solution every five years and cleaning of the solar panels every two years, the Kayema system could last between 15 and 20 years.

18) How much maintenance is required?

While most geysers are fitted with a sacrificial anode which requires replacing every two years, Kayema’s system’s PEX lining eliminates any need for a sacrificial anode. You’ll only need to replace the glycol solution every five years and clean the solar panels every two years to maximise performance.

19) Aren’t heat pumps cheaper?

While heat pumps are a better alternative to electrical geysers, they still run on electricity. Solar water heating systems operate independently of a power supply. Furthermore, most heat pumps will only offer a 24-month guarantee as opposed to the 10-year guarantee on Kayema’s solar power system.

23. What are the advantages of thermosiphon over a pumped system?

Although Kayema offers a full range of home solar power systems we prefer to focus on thermosiphon. A thermosiphon system, which comprises of a geyser and flat plat collector mounted together on the roof, uses a natural rule of physics, which dictates that cold water flows downwards and hot water flows upwards. As long as the geyser is positioned above the solar panel, it will allow hot water to remain in the tank and cold water to circulate without the use of a pump. It’s a completely natural process and requires no electricity or moving parts. Because the system is externally mounted on the roof it will not damage the internal structure of the house if it should fails or burst.

24. There are cheaper systems on the market, what justifies Kayema’s price tag?

Owing to its superior engineering and high efficiency, the Kayema system carries a 10-year guarantee. Over 2 million of Kayema’s solar panels have been installed throughout the world. To ensure that every system conforms to our high standards, we spare no expense in the manufacturing and development process. Investing in a high quality solar power water heating system, with a long lifespan will save energy, shortens the pay-back and soon justifies the initial price tag.