Why a solar water heater as first prize?
Solar water heating uses a free resource (sunlight on a roof) that is otherwise wasted, and leaves more electricity available for extending access or for other household uses. Domestic water heating generally accounts for between 40 and 50% of energy used in suburban South African homes, which are connected to grid electricity. Solar water heating saves money by cutting energy bills.
Domestic solar water heaters (SWH) usually pay for themselves in 3 – 5 years and, when appropriately sized and correctly designed and installed, provide approximately 70% of the energy required for domestic water heating. It is the kind of technological innovation that middle to upper-income home can afford to buy ? that is, our target market. Solar water heating - particularly if used with no, or with limited and time-controlled electric back-up - reduces demand during peak consumption period, thus reducing the demand that is the main driver for development of new coal or nuclear power stations.
Homemade systems can be made from scrap material [e.g. in Santiago, Chile, cold-drink bottles painted black are placed in glass-fronted boxes lined with reflective foil to heat dish-washing water]
Benefits of a Solar Water Heater (SWH)
The following are some of the benefits of an expanded SWH industry:
- SWH technology is well established in SA, and quality products are already manufactured and marketed both locally and abroad.
- Not only are SWHs benign, but they offer a significant opportunity for securing carbon credits (under the Kyoto Protocol's Clean Development Mechanism).
- SWHs use all locally produced materials.
- SWHs constitute a significant low cost job creating opportunity.
- SWHs provide a less expensive method of heating hot water, based on life cycle costing techniques, than electricity.
Hot water heated by solar contributes significantly to domestic hygiene.
- An expanded SWH industry could reduce electricity demand to such an extent in SA as to delay the need for constructing another power station at this time - coal fired power stations are responsible for extreme air pollution (particulates of SOX and NOX ? responsible for many respiratory diseases) making SA the 15th highest emitter of greenhouse gasses in the world.
The major disadvantage of SWHs is that the initial capital cost is generally higher than most other methods of heating domestic hot water, but after three years it pays for itself and one's energy bill goes down significantly.
|
