Solar Geysers 101
22/January/2010 08:00 Filed in: Energy Savings | Alternative Energy Solutions
Let's take a little closer look at geysers which are responsible for enormous amounts power usage on the grid.
Most geysers are 3kW. If you multiply that by just 3 million homes and you have a potential electricity usage of 9,000,000 Kilowatts. That's about 3 Eskom power stations. How much coal is that every day?
Automatic Control Panels come standard with many solar water heaters. This consists of a processor, solenoid and a small circulation pump which makes it possible to circulate only heated water to the geyser, otherwise heated water is lost at night or during colder periods.
As far as we can tell there are no comparisons available to compare solar water heater systems in terms of efficiency, but then who cares when sun energy is free (for now). Sin tax could become sun tax one day... Let's hope it doesn't.
There are 3 basic solar water heater systems available in South Africa.
1. Direct heating
Normally it consists of a solar panel and geyser connected to it.
An approximately 1000mm x 500mm solar panel, depending on the various manufacturer`s designs, consists of thin pipes connected to a bigger inlet and outlet manifold.
The absorbed heat causes the water to circulate through the system and the geyser temperature depends on the design and amount of sunlight.
The panel can be made from certain UV plastics, copper, stainless steel etc.
These systems seldom have Automatic Control options and at night the heated water cools off because nothing stops the circulation when the temperature drops.
Another disadvantage of this system is that it may be damaged when temperatures below freezing point results in burst pipes or just iced up pipes.
The main advantage is the cost, it is fairly simple and economical.
2. Indirect heating systems
This system is slightly more sophisticated. It could be a copper or a stainless steel system.
The system consists of a solar panel, a heat exchanging element, (very much like an electric element), a geyser and an automatic control panel with a solenoid and circulation pump.
It is called a closed system because the anti freeze is used as the heat transfer agent and it this overcomes frozen pipe problems.
3. Vacuum tube systems
This is probably the latest invention in Solar water heating.
All the previous solar panel designs are basically the same, however the difference is that in this case the solar heating pipes are enclosed in vacuum tubes!
The vacuum in the tube insulates the thin pipes in the solar panel against the elements and it is not affected by external fluctuations in temperature!
The direct heat absorbed from the sun`s uv rays is transferred to the water directly, instead of through a medium like antifreeze and this an advantage.
The vacuum tubes will probably have to be replaced after 5 to 10 years, however the specific system I am referring to is very popular in Europe and carries the European Buro of Standards approval, which is not easily granted.
Once again it comes with its own Automatic Control Panel with all the obvious advantages mentioned above.
Why do we tell you about solar energy?
Efficient Electrical Energy management is committed to the more efficient and effective use of electrical energy to reduce the carbon footprint, save coal, have less power stations and start employing the God given sources of energy, which is so abundant and free. What an enormous (albeit underutilised) gift we have in the sun`s vast generous source of energy.
In India the government had to find a solution for hot water in rural areas because the poor were destroying the precious forests for firewood. A subsidy scheme was launched to make it possible for anyone to buy a solar water heater. The results were amazing, a huge reduction in time spent finding firewood and the forest could “breathe” again. Apparently this scheme is still growing.
Most geysers are 3kW. If you multiply that by just 3 million homes and you have a potential electricity usage of 9,000,000 Kilowatts. That's about 3 Eskom power stations. How much coal is that every day?
Automatic Control Panels come standard with many solar water heaters. This consists of a processor, solenoid and a small circulation pump which makes it possible to circulate only heated water to the geyser, otherwise heated water is lost at night or during colder periods.
As far as we can tell there are no comparisons available to compare solar water heater systems in terms of efficiency, but then who cares when sun energy is free (for now). Sin tax could become sun tax one day... Let's hope it doesn't.
There are 3 basic solar water heater systems available in South Africa.
1. Direct heating
2. Indirect heating systems
3. Vacuum tube systems
Why do we tell you about solar energy?
Efficient Electrical Energy management is committed to the more efficient and effective use of electrical energy to reduce the carbon footprint, save coal, have less power stations and start employing the God given sources of energy, which is so abundant and free. What an enormous (albeit underutilised) gift we have in the sun`s vast generous source of energy.
In India the government had to find a solution for hot water in rural areas because the poor were destroying the precious forests for firewood. A subsidy scheme was launched to make it possible for anyone to buy a solar water heater. The results were amazing, a huge reduction in time spent finding firewood and the forest could “breathe” again. Apparently this scheme is still growing.