Eskom urges homeowners to service their solar water heating systems twice a year following change to SABS standard.

Homeowners who have installed solar water heaters with mechanical dump valves are urged by Eskom to service their systems at least twice a year to ensure they are protected against frost and freezing.

Homeowners looking to install a new solar water heating system are advised to make sure a mechanical dump valve is not used when their system is installed.

This follows a recent update to the South African Bureau of Standards’ (SABS) standard for solar water heating system installations. The updated version, South African National Standards (SANS) 1307, indicates mechanical dumps valves do not have adequate freeze protection and could be at risk of failing or becoming unsafe. The use of mechanical dump valves in solar water heating system installations is now prohibited by the SABS.

Andrew Etzinger, Senior General Manager, Integrated Demand Management department, Eskom, said: “Although certain systems that use the mechanical dump valve passed the SABS freeze test, they do not provide adequate freeze protection if they have been incorrectly installed, are exposed to chlorine build-up, or are not correctly maintained.

“Homeowners who have already installed systems that use the mechanical dump valves need to ensure frequent maintenance is carried out; these systems must be serviced by a qualified technician at least twice a year. If regular, twice annual, maintenance is carried out, there is no cause for concern over the safety and performance of these systems.

“Homeowners should check with their installers whether a mechanical dump valve was used in their installations; it is also important for people who are considering installing a solar water heating system to be aware of the new SABS standard and ensure a mechanical dump valve is not used,” said Etzinger.

All installers registered with Eskom’s rebate programme for solar water heating systems have been advised of the update to SANS 1307, and will not be permitted to use mechanical dump valves in any future installation. Only systems that have passed SABS testing and comply with SANS 1307 for safety, and thermal and mechanical performance, qualify for the Eskom Rebate Programme.

Any South African citizen can apply for a discount on the purchase of a solar water heating system through Eskom’s rebate programme for the homeowner; to qualify for a rebate, homeowners must purchase an SABS-approved system from an installer accredited with Eskom’s rebate programme.

Detailed information is available on this page under “Solar water heating”.

Save electricity and save our planet with solar water heating. You’ll also be helping to reduce the amount of power shortages and cut down on the use of coal. Solar power is an unlimited, clean energy source, and South Africa’s sunny climate makes it an ideal solution. Think green & switch to solar!

Eskom is offering a rebated Solar Water Heating Programme, which promotes the use of solar water heaters. Solar technology uses the sun’s heat to supply your hot water, solar water heaters are environmentally friendly and can decrease your monthly electricity account by nearly half. The solar water heating programme is part of Eskom and the government’s commitment to help South Africans lead energy efficient lifestyles. When you use an SABS and Eskom approved supplier for the purchase and installation of solar water heating, we’ll give you a rebate of between R2 500 and R12 500 on the system.

Did you know that installing solar power to supplement or replace your existing geysers; can reduce your water heating bill by as much as 70%. You’ll need to work out your household’s hot water needs first, to ensure that you’ll have enough hot water for when you need it. Work it out by allocating 50 litres of water per person in your household and then add on an extra 50 litres for appliances that draw a large amount of water from the geyser. We recommend that you slightly oversize your system to maximize the hot water achieved through solar energy.

Solar water heating programme overview

List of accredited suppliers

Steps to claiming your rebate

Technical information

A note on self-installation

What are the criteria for solar water heating systems to qualify for the Eskom programme?

SABS test certificates, repairs and mark approval explained

Timer information

Usage tips

Frequently asked questions

Solar water heating: customer testimonials

View/download our brochure/s

Solar help desk

In an environment where electricity usage and costs are matters of increasing importance, the identification of technologies that lower the electrical consumption is becoming more important, especially in South Africa. A significant technology that is both simple and effective in lowering the electricity usage is the deployment and employment of heat pumps.

Heat pumps offer both households and other major consumers of electricity-like privately and commercially owned farms- a significant opportunity to reduce costs related to water heating. A heat pump can save up to 67% of energy consumption and in some instances and circumstances even more than that. At the moment most agricultural enterprises heat their water systems with geysers and inline elements called calorifiers with energy sources that include: gas, oil or coal. All of which are a strain on South Africa’s natural resources.

Heat pump is both an economical and environmental investment and can save you money. The heat pumps use the reverse cycle of a refrigeration plant to heat water. In effect it transfers heat from a source such as air or water to water which is to be heated.
As in other refrigeration equipment, the heat pump employs an evaporator, a compressor, a condenser, refrigeration gas and an expansion valve within a closed circuit. Latent heat is given off when the refrigeration gas is liquefied through the condenser and transferred to the surrounding water together with further “sensible” heat loss, effectively raising the temperature of the water to 65 degrees. In some circumstances even higher temperatures can be achieved. Generally there is no need for a hot water booster pump to achieve this result.

Heat pumps are typically mounted on the outside walls of buildings under the eaves or at ground level depending on the configuration of the system. It may seem strange that an electro mechanical device with moving parts-the electric motor driving the compressor-can be more efficient in heating water than a typical resistant-element geyser. In fact a heat pump can be up to three or four times more efficient than a hot water system which is powered by a normal resistant element because for every kWh of electricity supplied to the heat pump, more than three kWh of thermal energy in the form of hot water is produced. A thermostat will keep the hot water at a constant temperature between 55 degrees and 65 degrees with 60 degrees being the most commonly used setting.

An additional benefit which is often used to increase the economic benefits of a heat pump is that of the cooling system which can be utilised to simultaneously cool a building, or a specific area of a building.

The accompanying diagram represents the major components typical of a refrigeration system or heat pump where the refrigerant gas is circulated in a continuous cycle. The liquefied refrigerant gas is circulated in a continuous cycle. The liquefied refrigerant (mostly R134A) passes under pressure through an expansion valve into a partial vacuum. The sudden expansion of the high pressure liquid into a low pressure area (the evaporator) cools the gas down. The refrigerant gas which is now at a comparatively low temperature is then suddenly pressurised by the compressor.

The sudden increase in pressure raises the temperature of the refrigeration gas considerably. This heated gas is routed through a condenser and emits heat to the water that is to be heated in a storage tank near to the actual heat pump. It can also be emitted into the surrounding atmosphere in the case of a refrigerator or air conditioning system.

The benefits of heat pumps

Frequently asked questions

Lighting accounts for a substantial portion of the monthly energy consumption and costs of commercial and industrial buildings. In fact, lighting is estimated to be responsible for between 37% and 45% of electricity consumption many buildings. Over the years, commercial and industrial lighting solutions have evolved to fit modern building design and layout. The large variety of components available today means that there are lighting solutions to fit almost any context.
The following steps can be taken to improve the energy efficiency of an organisation’s lighting:

• Switch to energy-efficient lighting

  Replace magnetic ballast luminaries with energy-efficient lights (electronic ballast) such as T5 fluorescents and LEDs. LEDs have long been used to illuminate exit signs and brake and indicator lights on vehicles. Thanks to advancements in quality and colour rendering, they can now be used in a much broader range of applications. LED lights use dramatically less power while providing better light and reduced flicker. They also last much longer.
  Energy-efficient lights run at much lower operating temperatures than traditional bulbs and because they run cooler, there’s less heat for the air conditioning system to deal with and light fittings and cables do not deteriorate as quickly.

• Light up enclosed spaces separately

  Enclosed spaces should have individual light switches so that they are not left lit unnecessarily. These switches can be used in conjunction with room occupancy sensors.

• Install occupancy sensors

  Occupancy sensors control lighting based on occupant detection.
  These can be used to control lighting in intermittently occupied areas such as meeting rooms, toilets and print rooms.

• Deploy daylight sensors

  Use daylight sensors to brighten, dim or even switch off lights according to natural light levels as they change throughout the day. This will reduce operating and energy costs. The influence of artificial and natural lighting has been intensively studied, and it is proven that exposure to daylight and productivity is strongly related.

Use programmable control systems

Lighting control systems can switch off lights automatically or step-down lighting levels for night time security or reduced occupancies.

• Reduce consumption of down lights

  Switch to new generation compact fluorescent down lights bulbs which use 90 % less power than regular halogen bulbs. They are also light-weight, compact and last about four times longer than traditional incandescent bulbs.
  There are low-energy LED (bulbs) bulbs available for down lighting applications. However, these can be a little pricey, and opting for lower-cost varieties usually means compromising on colour, quality and distribution (spread) of light.
  Replace standard 50 watt halogen bulbs with either 35 watt or 20 watt bulbs. These will reduce the energy used, but will lower the light output as well. Install a dimmer on existing down light systems that will reduce the energy used, but will lower the light levels. The light output of these bulbs will decrease faster than the energy reduction, but overall there will be a reduction on the energy used.

Electric motors consume vast amounts of power. The older your motors are, the higher the chances are that they use more electricity than they should. You can reduce your bills significantly by replacing these motors with new generation “high efficiency” electric motors (Eff 1). Make sure that the motors you install can run at 3/4 of their capacity to perform everyday jobs. Running at full load for long periods requires much more power.