What is Solar Water Heating?
Solar water heating is a system for heating water using energy from the sun. Solar energy is collected by a panel/collector, which is then connected by pipes to a hot water storage device such as a hot water cylinder.

 

What are the benefits of Solar Water Heating?
Solar water heaters can help save water heating costs by reducing the amount of gas and electricity needed to heat water. By using sunlight to heat water instead of combustible sources or fossil fuel-produced electricity, fewer pollutants are being introduced into the environment. Solar energy is not affected by the current shortage of electricity and does not stop providing hot water during load shedding.

 

How much of my total hot water requirements can a Solar Water Heater supply?
A solar water heater can provide between 50% and 90% of your total hot water power requirements, depending on the climate and model of heater. When you don’t use the element you will save 100% of your hot water power requirements.

 

By how much will replacing a conventional geyser with a solar powered system reduce electricity consumption?
The electrical geyser uses on average between 30 – 50% percent of your household’s monthly electricity bill. Replacing your conventional geyser with a solar powered system will reduce that percentage of your electricity consumption by up to 70%.

 

What is Eskom`s involvement in the Solar Water Heating program?

In order to reduce the growing demand for electricity, Eskom is embarking on energy efficiency and alternative energy programs that promote energy savings on a large scale in order to mitigate system constraints. Eskom is working towards a goal to meet government’s target of 10 000 gig-a-watt hours of renewable energy. Part of this is the financial assistance in the form of a rebate to assist hot water consumers to convert to solar.

 

How hot can the water get?

The ideal temperature of your geyser or tank is between 55 and 60⁰C. Most solar systems heat the water to between 55 – 65⁰C, but some can heat much higher than that. You need to be aware of over-performing systems so that you are not scalded by the hot water.
Unless otherwise required the water temperature at the point of use should be at, at least 38⁰C for domestic fixtures such as baths, basins and showers and at least 45⁰C (in order to melt fats) for sinks. The temperature is not meant to exceed 55⁰ C at any point of use.

 

What happens in winter or on rainy days, when there isn`t enough sunlight to heat the water?

Solar water tanks are better insulated than electrical geysers and can keep water hot for a longer period of time. This ensures that there is always a tank full of hot water (and a backup of hot water) in the early evenings/mornings – provided the tank size is correct. An electrical backup system is allowed on the program provided it has a timer switch that ensures it does not operate during Eskom’s peak demand periods. Customers need to ensure suppliers/installers appropriately insulate all the pipes exposed to the elements to prevent freezing and heat loss.

 

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 utilised with solar collectors as they do not have sufficient inlets and their linings are often not designed to withstand the temperature experienced from solar energy. The supplier should evaluate the existing geyser and, based on your needs, the supplier can evaluate the possibilities of using the existing system.

 

What is the life-cycle expectation of the system and the total energy savings on it?

Each piece of equipment has a different savings profile which depends on various elements such as geographical area, water usage profile, number of users and the size of the system. However, on a 200 litre system, the SABS average is 5.67kWh per day at 16MJ input power. The expected life of the equipment can range from 5 to 15 years; most systems are guaranteed for 5 years.

 

Where can I obtain information on accredited suppliers?
The suppliers that are part of the rebate program (those that have passed quality and reliability tests) are listed in the supplier database on the website. There are other suppliers in the market, but if they are not part of this program to reduce costs to the consumer, they may not have been passed through the SABS testing or approval or may not be part of the industry body.

 

Why is it important that a solar system be tested by SABS?
The specifications on solar water heaters focus on three main areas: quality, performance and safety. Testing systems verify these requirements. As the payback periods are very important it is vital that the solar water heater is of a quality that ensures system longevity.
The mechanical performance tests e.g. hail, freezing and pulsation test (testing of the valves) 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.

 

Why is it important that solar systems get the SABS mark of approval?

The SABS mark of approval takes the test report and adds an evaluation of the manufacturer’s ability to consistently produce quality solar water heating systems. This means that if the testing indicated a high quality, durable and safe solar water heater design, and the manufacturing quality audit indicated that the manufacturing facility can manufacture high quality products consistently, the SABS will allow the manufacturer to use the SABS mark.

 

Can I install the system myself?

In order for you to qualify for the rebate, the solar system has to be installed by an approved installer. Even though the concept of the system may look simple, many areas can be damaged if the system is not installed by a qualified tradesperson. Accredited suppliers register their installers and undertake to oversee the installations to ensure that they comply with program and building regulations and other applicable legal requirements. A new plumbing regulation body has recently been formed (PIRB) which will allow customers to identify qualified and licensed plumbers. Therefore, if you have purchased a qualifying system and your local plumber is registered on the program to install that system, you will be able to make use of them. The guarantees can be lost if it becomes evident that someone without the correct technical expertise has tampered with the system.

 

How do I ensure the quality of the system I have purchased?
Purchasing a system that is registered on the Eskom program ensures that the system and the supplier have been checked and audited to the SABS minimum standard for solar water heaters, not only safeguarding you as a consumer but also giving you greater assurance of the system’s quality. Buying an Eskom registered system means you qualify for a rebate, making your purchase good value for money.

 

How much can it save in your typical electricity bill?
A geyser uses between 30 – 50% of the electricity used in a home. Typically taking overcast weather and usage patterns into account, 70% of this energy can be displaced by a solar system.

 

Given our current electricity shortage, how much can solar water heaters help reduce demand?
If 100,000 geysers were to be installed this would offset 300 MW worth of connected load. However if we take diversity and usage into account this equates to a 63 MW load that is actually removed during our peaks.

 

What is the typical payback period for a Solar Water Heater?
With the current rebates in place paybacks are typically between 5 years or less, depending on geographical area, water consumption patterns, number of people in the household, type of system chosen and energy cost.

 

Where can I get registered as a supplier on the program?

Anyone interested in becoming a supplier can contact Deloitte by email on eskomswhproject@deloitte.co.za. Questions on the solar water heating program can be answered by our DSM Help Desk: Email: solar@eskom.co.za Tel: (011) 800-4744 during office hours.

 

How do I know which system to choose for my climate?

Areas that experience frost (such as Gauteng) should only make use of freeze resistant systems. We do not have severe winters in South Africa, but we do have frost and temperatures below 4oC, which can cause systems to burst and fail.

One of the tests that the SABS does is a freeze test to ascertain whether the systems can actually withstand low temperatures. Non-frost areas tend to be in a narrow band of the South African coast line. All inland areas are prone to frost so if you live inland, you should buy a system that is tested to withstand frost conditions. Furthermore, water in South Africa can be very corrosive, especially when the water is hot. If systems are not manufactured to withstand our water quality then the components do not last for the guarantee period. Critical parts that need to be suitable to our water quality are valves, copper pipes, and the lining of the storage vessel. Indirect systems can handle both frost and poor water quality.
Finally, South Africa has very high levels of radiation and therefore system performance can decrease. Just because a system has an overseas test report does not imply it is designed to handle the high temperatures it will be exposed to here. Systems that get too hot are potentially very dangerous and should be configured for our radiation levels.

 

What is the lifecycle of a Solar Water Heating system?
A solar system has a lifespan of 5 to 20 years depending on the system and the maintenance on the system.

 

When will legislation be ready on all new buildings and when will tax rebates be available?
The regulation for new buildings has already been gazette. All new buildings will have to be energy efficient by law. As for the tax rebates; once the application has been submitted to SARS, but there were no timelines or guarantees provided.

 

How are companies making use of solar heating in South Africa?
Eskom is planning to offer solar systems for industrial and commercial applications with financial incentives. Commercial applications are those that make use of boilers and large arrays of solar collectors. These include larger property developments that have the roof space and that require hot water to be created using a green environmentally-friendly energy generation method. Hotels and bed and breakfasts, which are measured on their energy efficiency and their conservation efforts in terms of water and energy, are looking to solar solutions. Industrial applications such as mining houses that require large quantities of sanitary hot water are looking at solar power to generate the large volumes of hot water required per shift.

 

What about bulk domestic installations?
Bulk installations such as when a developer builds a complex of townhouses or flats, can claim an incentive per installation. Contact our Solar Help Desk for information around these installations.

 

What is solar water heating ?
Solar water heating is a system for heating water using energy from the sun. Solar energy is collected by a panel/collector, which is then connected by pipes to a hot water storage device such as a hot water cylinder.

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