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, which is 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 provide?
A solar water heater can provide between 50 and 90 percent of your total hot water requirements, depending on the climate and model of heater.
By how much will replacing a conventional geyser with a solar powered system reduce electricity consumption?
The electrical geyser uses 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 percent.
What is Eskom’s involvement in the solar water-heating programme?
In order to reduce the growing demand for electricity, Eskom is embarking on energy efficiency and alternative energy programmes 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 gigawatt hours of renewable energy generation by 2013.
How does the programme work?
The programme is structured around a rebate that reduces the selling price of a SABS approved solar water heating system. The reduction in price is based primarily on the performance of the solar water heater and its associated electricity saving potential. You receive a rebate directly from Deloittes, the facilitating auditors of the programme.
Only registered products, complying with the following criteria, qualify for the rebate:
The system must have a timer to optimize energy savings and regulate everyday usage.
The system must be appropriate for the household and area in which it is installed, in terms of size, frost protection and water quality compatibility.
It must have a comprehensive guarantee of at least five years.
The system must have passed the South African Bureau of Standards (SABS) tests, and comply with the South African National Standards (SANS) for thermal and mechanical performance and safety.
The supplier of the system must be registered with SESSA (Sustainable Energy Society of South Africa) solar water heating division.
A registered installer must install the system and the customer will only be able to claim the rebate once facilitating auditors receive a final invoice from their supplier.
Does the fact that the industry is still developing and has not been exposed to legal and quality regulations before contribute to a slower than expected rollout of the programme in the country?
One of the main benefits of the solar programme is that an effective quality standard is now in place, in accordance with building regulations that require SABS testing. It is a legal requirement that a certificate of electrical compliance has to be issued for new installations or any alterations to the electrical system including the replacement of a geyser.
The accreditation of a supplier by Deloitte, Eskom’s facilitating auditors, takes 2 weeks. The SABS testing of a system takes from 6 – 8 weeks. However, the testing time is reliant on the available sunny days and from time to time, a back log at SABS means that there is a waiting list to get systems booked in.
For these reasons, a phased, cautious marketing approach will be followed by Eskom to ensure that suppliers are able to cope with the demand.
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 utilized 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 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 back-up of hot water) in the early evenings/mornings provided the tank size is correct. An electrical back up system is allowed on the programme provided it has a timer switch that ensures it does not operate during Eskom’s peak demand periods.
How hot can the water get?
Most solar systems heat the water to 55 degrees Celsius. You should have a timer installed with your system, as it has been shown that this will give you the maximum energy saving and ensure you have hot water in peak periods.
What is the life-cycle expectation of the system and more significantly the total energy savings on it?
Each piece of equipment has a different savings profile that 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 is 15 to 20 years; most systems are guaranteed for 5 years.
Why is it important that a solar system be tested by SABS?
The specifications on solar water heaters focus on three main areas, i.e. 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 the longevity of a system. The mechanical performance tests e.g. hail, freezing and pulsation test 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 approval?
The SABS mark 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?
The installation of a solar system, to qualify for the incentive, has to be done by an approved installer. Even though the concept of the system may look simple, many areas can be damaged if a qualified installer does not install the system.
Accredited suppliers register their installers and undertake to oversee the installations to ensure that they comply with programme and building regulations and other applicable legal requirements. Guarantees can also 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 programme ensures that the system and the supplier have been checked and audited, 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 does this subsidy work?
Home owners who purchase a solar system from an Eskom accredited supplier will receive the rebate directly into their bank accounts after they have claimed it, provided that the system and the supplier have been registered on the programme, and that the installation is done by an installer registered by the supplier.
How much does a typical system cost and how much is the incentive?
The reduction in price (rebate) is based on the electricity-saving potential of the specific product as tested by SABS. In other words, the more energy efficient the solar system, the more electricity it will displace and thus the bigger the rebate. Each solar system will have its own rebate value according to the energy footprint measured by SABS.
The cost of installing a solar geyser varies between R 12 000 to R 35,000.00 depending on the size, type, and source (i.e. imported or locally manufactured). The rebate calculates to between 15 to 30% depending on the equipments’ energy savings capability.
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 crisis, how much can solar water heaters help reduce demand?
If a 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.
How much money has Eskom devoted to the subsidy programme?
Eskom DSM is currently managing the R2 billion allocated by NERSA for the solar programme, this covers programme development, marketing and funding the incentive.
What is the typical payback period for a solar water heater?
Paybacks are typically 5 years, depending on geographical area, water consumption patterns, number of people in the household, type of system chosen, and energy cost.
The South African manufacturing capacity is only 10 000 per annum. Is Eskom actively addressing the shortage?
We are in discussions with a number of international suppliers and local funding institutes to establish manufacturing plants for this equipment in South Africa. We are also working towards minimizing the import duties on the solar water heating equipment to promote imports of this equipment in the short term. This should be seen as an opportunity to kick start an industry that is ideally suited to South African conditions.
How does solar water heating work?
Solar water heaters use two natural events in order to function: dark coloured objects absorb heat (solar energy) and hot water rises. Technology has made this natural phenomenon a working reality for a reliable source of hot water in our homes and for a range of other applications.
A solar water heater is a combination of three elements:
Solar collector an energy device, designed to absorb solar radiation and transfer the energy to the energy transfer fluid or material passing through the collector.
Energy transfer medium – is a medium that through the process of conduction or convection, transfers the absorbed heat to the water. The type of material used is dependant on the design and needs of the installation. Where freezing of the transfer medium is a concern, the liquid used should be mixed with a non-toxic coloured anti freeze liquid and a corrosion inhibitor.
Solar water system tanks/storage vessels should always be larger than conventional household geysers. This is because the sun is heating the total volume of hot water that is required for the day. For your conventional 150-litre electric geyser to heat 300 liter it will need to cycle and heat the extra body of water. A thermally insulated hot water storage vessel or geyser with a protected inner lining, copper, steel or a polymer should be used. There are solar water heating systems that work on a low pressure, but most are pressurized from 100 kPa to 600 kPa, depending on the materials used.
Solar water heaters can be plumbed in series to pre feed your existing geysers, or can completely replace existing geysers. The complete system can be mounted on top of the roof, if the structure can hold the mass, or the hot water storage vessel can be mounted under the roof at a high level or at ground level in a utility room or cupboard. Solar water geysers/storage vessels function best when mounted vertically. However if there are physical or aesthetic concerns the geyser can be mounted horizontally.
There is a shortage/non-existence of qualified installers, usually the role of the plumber. How will this be addressed in the short term?
Eskom is facilitating the development of installer training and upskilling through the SETA’s and various stakeholders such as the DPE. For the interim the role of training will fall onto the supplier and in-house training houses, although we are starting to see the development of independent trainers offering courses which will assist for the new entrants into the market.
Only limited manufacturers have the SABS mark. Tests cannot possibly be compared to the full mark. What window period, if any, is Eskom allowing for all other manufacturers/suppliers to obtain the mark?
We allow companies into the programme with only a test report, but provide them with an 18-month window period before requesting that they move to the Mark Approval. As at 24 November 2009 9 suppliers have the Mark Approval, with at least four in the process of application
Some solar suppliers have no intention of getting tested never mind the mark. How does Eskom respond to this?
There is currently no legal stipulation for suppliers to test and conform to all SABS standards. Eskom wants to see the inception of quality and safe systems into the market to ensure the longevity of the industry and therefore our communication strategy will largely revolve around customer education as to the benefit of purchasing an SABS tested system or one with Mark Approval. Our hope is to encourage customers to make an educated purchase so as to not be forced to purchasing again in a few years to due possible poor quality. The programme is in no way exclusive to a technology or supplier and we hope that the programme requirements that are in place to assist in ensuring a sustainable market and protect customers should be seen as a benefit and not a deterrent.
Does Eskom get complaints about the quality of solar water heaters?
The number of suppliers selling systems has grown from around 10 to over 150 in the last year. The aim of the Eskom programme is to encourage consumers to purchase solar water heaters (even off the programme) however a great deal of the available systems are not designed for South African conditions and will not provide the consumers long term savings results. Eskom wants to protect the market against poor quality systems, thereby assisting to ensure the longevity of solar water heating in the country.
Could you expand on the “rigors” of SA climate, please? In Gauteng it must withstand low temperatures and frost. What about the other provinces?
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 the occurrence of frost and temperatures below 4 degrees that 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 a narrow band of the South African coastline. All inland areas are prone to frost and consumers should therefore purchase a system that is tested to withstand frost conditions. Further, 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. Finally, South Africa has very high levels of radiation and therefore a systems performance can increase. 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.
Do solar water heaters, with only a test certificate (and not the SABS Mark of Approval), qualify for this rebate?
Yes, however the Test certificate is only valid for 18 months and then the programme requests that suppliers move to the Mark Approval as this is a far better form of quality assurance as it is not simply a once off test on a system. The mark approval ensures that components tests are repeatedly of a good quality due to the regular system tests.
How many domestic households have made use of Eskom’s solar initiative since it was introduced in 2008?
At end September 2009 2261 systems were installed
Home owners who purchase a solar system from an Eskom accredited supplier will receive the rebate directly into their bank accounts after they have claimed it via Deloitte, provided that the system and the supplier have been registered on the programme, and that the installation is done by an installer registered by the supplier.
The reduction in price (rebate) is based on the electricity-saving potential of the specific product as tested by SABS. In other words, the more energy efficient the solar system, the more electricity it will displace and thus the bigger the rebate. Each solar system will have its own rebate value according to the energy footprint measured by SABS.
The cost of installing a solar geyser varies between R 12 000 to R 35,000.00 depending on the size, type, and source (i.e. imported or locally manufactured).
How much per month can households save?
The electrical geyser uses 30 – 50% of a household’s monthly electricity bill. Replacing ones conventional geyser with a solar powered system will reduce that percentage of ones electricity consumption by up to 70%.
Why is there an insistence on a five-year guarantee in respect of Eskom’s domestic electricity rebate programme when the industry norm is far less?
In South Africa the industry norm for a conventional electrical geyser was 3 to 5 years and that of solar geysers was between 3 to 10 years. Internationally the solar geyser norm is 5 to 10 years. The average expected life span of a solar system is between 10 and 20 years depending on a number of factors.