2004-11-28
I'm Gwen Outen with the VOA Special English Development Report.
Solar water heaters save on energy costs. They also save on oil
and other forms of energy needed for electric or gas-powered water
heaters.
The Taiwan News reported this month that the Ministry of Economic
Affairs will increase its budget for a program to help pay for solar
water heaters. The program was supposed to end this year. But
officials have decided to continue it through next year. A ministry
official said Taiwan is among the top users of solar water heaters
in the world.
Solar water heating is used worldwide. The device we are about to
describe was developed in Afghanistan more than thirty years ago.
Since then, it has been used in many countries. It can heat seventy
liters of water to sixty degrees Celsius. It can do this between
sunrise and noon on a clear day with an average outside temperature
of thirty-two degrees Celsius.
There are two parts to the solar water heater. One part is the
solar collector. This is made of metal sheets painted black. The
collector is placed in contact with the water.
There are several kinds of metal sheets that can be used for the
collector. Metal sheets that have raised sections will work very
well. These corrugated sheets often are used to make the roofs of
houses.
Once the water is heated, it is kept hot with insulation
material. This helps the water stay warm for a long time.
The second part of the solar water heater is the storage tank.
The tank can be a container that holds about one hundred liters. Two
rubber pipes are attached to the storage tank. One pipe lets water
flow into the system. The other lets water flow out.
When the water heater is working correctly, water will flow from
the storage tank to the collector and back again. You can use the
hot water at the top of the tank for washing and cleaning. You can
change the flow of water so that the temperature is hot or warm as
desired.
This solar water heater is easy to build and operate. It will
last about two years before the rubber pipes need to be replaced.
However, it will heat water only on sunny days.
You can get more details from the group Volunteers in Technical
Assistance. VITA is on the Web at vita.org. And you can find more
Development Reports at WWW.testbig.com.
This VOA Special English Development Report was written by Gary
Garriott. I'm Gwen Outen.