WHAT IS SOLAR WATER HEATING?
Solar energy is, literally, energy derived from the sun.
According to mechanical engineers at the University of Wisconsin’s Solar Energy Laboratory, an average four-person household with an electric water heater requires 6,400 kWh of electricity per year to heat their water. Assuming the electricity is generated by a typical power plant with an efficiency of around 30%, this means that the average electric water heater is responsible for approximately EIGHT TONNES of Carbon Dioxide emissions annually, which is almost DOUBLE that emitted by a typical modern automobile.
Solar water heaters provide an excellent alternative for heating water by using energy from the sun to heat water in a clean, safe and sustainable manner. Because the source of energy is the sun, which is a freely available natural resource, the household is protected against the inevitable increases in the price of electricity, paraffin and coal. Also, use of geysers to heat water is a major contributor to peak electricity demand and solar water heaters are, therefore, an important solution to the national electricity generation crisis as well as local electricity distribution constraints.
BENEFITS OF SOLAR WATER HEATERS
No cold water due to LOAD SHEDDING
- Save up to 90% of your water heating bill monthly
- Reduce electricity consumption by up to 40%
- Guaranteed for 10 years
- Guaranteed return on investment. Then it’s FREE POWER!!!!
All our solar geysers are SABS and Eskom approved, come with guarantees and qualify for applicable rebates.
HOW DO SOLAR WATER HEATERS WORK?
The solar water heater consists of three main parts: the collector, the storage tank, and the frame. The collector is the part of the solar water heater that captures the incoming solar energy as heat, which is then transferred to the water directly.
The tank and vacuum tubes are filled with water and are heated by the sun. As the water in the tubes gets warmer, the water rises and mixes with the colder water from the tank, eventually heating all the water to a high temperature. This natural phenomenon is called the Thermo siphon effect. Thermo siphon systems operate on the difference in densities of hot and cold water. The hot, less dense water rises in the tubes to the tank. No external pump system with an energy source is required.
The system incorporates a self-regulating filler tank that can be directly connected to the main water supply. As hot water is withdrawn from the main tank, the filler tank allows cold water in to the tank. A ball valve will stop the incoming cold water supply when the water level in the filler tank reaches a certain level. This ensures that the tank is always full.
TECHNICAL SPECIFICATIONS
The 110L Eco-sol geyser is 1230mm long, 460mm in diameter, and weighs 16.44kg. It is constructed of Grade 444 stainless steel, with a thickness of 0.7mm. The outer wrap is manufactured from 0.45 precoat alu zinc and the end caps from polypropylene. The tubes are of Chinese origin with an SABS approved thickness of 2.3mm. The isolating material is ecofoam, which is 2015 protocol compliant and applied to a thickness of 50mm between the inner and outer tank. The tank uses a 47mm diameter, 12 tube array. The tubes are 1800mm long. Framework is available in various forms to ease installation and this particular hot water heater is of the gravity feed cistern design. No electric element is typically available for this type of unit but that will become an option in the future. All components except the evacuated tubes are manufactured locally.
The frame is simple, allowing quick assembly and installation. It is adaptable to any roof condition. The filling system is approved at 14 bar pressure. The complete system is SABS tested and passed.
The whole system has been designed and adapted to suit Africa’s harsh climate.
For detailed technical information on our solar water heating systems and components, please refer to the following files:
Advantages of Evacuated Tubes Non-Pressurised Solar Water Heating System Indirect Solar Water Heating System Solar Water Heater RetrofitFREQUENTLY ASKED QUESTIONS
Q: Do solar water heating systems work when there is no direct sunshine?
A: Yes. Although clouds reduce the direct component of solar radiation from the sun, diffused radiation from the clouds and sky can still produce sufficient heat energy for heating water in a solar water heating system.
Q: Can cheap components be used in the construction of solar water heating systems?
A: No. Materials for the construction of a solar water heating system MUST be selected to suit local atmospheric and water conditions. Solar water heating systems are subjected to extreme weather and temperature conditions (heat, cold, rain, snow, wind, etc.) and, unless they are carefully constructed with high quality materials, they will have a reduced life span and will not be economical in the long run.
Q: Are solar water heating systems visually attractive?
A: Solar water heating systems can be made to be visually attractive if care is taken in their design and installation.
Q: How big should a solar water heating system be?
A: The size of the solar water heating system is affected by a number of factors, such as the volume of hot water required per day, whether back up energy is available, the cost of back up energy and the cost and life span of the solar water heating system.
Q: Should a solar collector always face true north?
A: Deviation of the collector orientation by up to 45 degrees from true north reduces the solar radiation by only 9%. A collector orientation of true north ±45 degrees is therefore still acceptable. However, the closer the collector faces true north, the better.
Q: What is the best angle of tilt above the horizontal for a solar collector?
A: For the best year-round operation, the angle of the collector above the horizontal should be the latitude of the locality in which it is installed plus 10 degrees, although deviations of 10 degrees in either direction will not reduce performance substantially.
