| Solar Water Heaters |
| Wednesday, 20 August 2008 00:12 |
|
Installing a solar water heater will reduce your electricity consumption which in turn reduces the CO2 emissions. In Malta, the heating of water is normally achieved by using electricity or direct burning of fuel such as LPG or fuel oil. Whichever of these two methods is used to heat water it invariably burns fuel which costs money and emits greenhouse gases. Solar water heaters (SWH) can be a cost-effective way to generate hot water. They can be used in any climate, and the fuel they use (sunshine) is free. Solar water heating systems almost always require a backup system for cloudy days and times of increased demand. Conventional storage water heaters usually provide backup and may already be part of the solar system package. Considering that locally there are approx. 11 days a year with very cloudy conditions, most users of correctly installed SWH systems report that they only use the backup systems once or twice in whole year. Locally, a typical (3000 W) filament water heater “geyserâ€, consumes 3285 kWh/year, which compares well to the OECD average of 3200 kWh/year. But producing that electricity in highly inefficient fossil fuel power stations, and then transmitting that electricity down the power line (which is also a very inefficient process) to your home costs some 9,600 kWh in electricity wasted as heat - so roughly two thirds of the energy is lost before it even reaches your home. By using a gas/oil water heater, one bypasses the losses created at transmission levels and reduces energy use to 3,800 kWh. By replacing the typical “geyser†with a solar water heater one could be saving approximately €500 yearly (including surcharge). Assuming one buys an average solar water heater at the cost of €1000 this could mean that the recovery period for this “investment†is equivalent to two or three years. One also has to remember that there is a Government rebate of 25% of the value paid for the solar water heater, up to a maximum of €230 (Lm100). But what if one cannot afford the initial €1000 investment to buy a solar water heater? There are still things one can do to save energy. In countries like Austria it has become quite popular to build your own “home-made†solar water heaters for a fraction of the price. If that is not an option, one can still increase the efficiency of the typical filament water heater. When buying a new “geyser†one should calculate the correct volume as compared to the size of the household. Regular services should be made and the temperature setting should be changes according to the use (i.e. set to 60°C in winter and 45°C in summer). It is also advisable to turn the “geyser†off when not in use especially if it will not be used for more than 6 hours. This will not give you the same levels of savings as compared to buying a solar water heater, but by becoming more efficient when using typical household equipment, one might save enough money to be able to afford to go to the next step and invest in a solar water heater. |
