Renewable energy perspective plan of nepal 200-2020 an ... - SNV

proposes. With the growing energy needs more efficient devices are being developed
to utilize solar energy. There are mainly two methods of using solar energy: One is
Sola r. Thermal and the other is Solar Photovoltaic.
4.3.1 Solar Thermal Energy
In this methods heat from solar energy is used directly by using efficient devices.
There are also different technologies to use solar thermal energy.
• Solar water heater
• Solar dryer
• Solar cooker
• Solar passive building
a) Solar Water Heater
The history of the production of Solar Water Heater dates back to 1968 when first
commercial solar water heater was produced. In 1974, the plumbing division of
Balaju Yantra Shala started limited production of Solar Water Heaters.
It is estimated that there are about 120 manufacturers of SWH in Nepal. However, the
number of manufacturers alone may give a misleading information as none of the
manufacturer mass-produces the SWHs, in an assembly line. Each SWH is
individually produced. A significant use of solar energy has been in water heating in
households as well as in hospitals, schools, hotels and lodges. Solar water heaters are
produced and marketed commercially. Altogether, about 17.265 solar water heaters
were estimated to be installed in 1997-'98 (WECS. 1998).
The SWHs produced in Nepal are suitable for use in hilly and Terai region of Nepal.
Although there is a large potential for use of SWHs in northern highlands, the locally
manufactured SWHs. available in the local market are not suitable for regions where
temperature reaches sub zero.
The-most difficult aspect of the locally produced SWHs is the lack of technical
information in terms of the standard parameters and the performance curves. One
information, which is generally given to the buyers, is the maximum temperature.
However, the maximum temperature figure alone, in the absence of other pertinent
data such as water discharge rate. -installation angles, etc. do not "tell" any substantive
story about the product to the prospective user of SWH.
b) Solar Dryer
Solar dryers are used for drying agriculture products with the systematic use of solar
thermal energy. Recently efforts have been made to develop solar dryers for largescale
crop drying. Major application is being developed primarily for drying of herbs
and vegetables. There is no standard capacity range. There is no large-scale domestic
use in Nepal due to lack of awareness and financial incentives. Different
organizations have developed but no known commercial manufacturer specializes in
dryers. It has not yet received wide commercial acceptance from likely users. If
systematically designed and awareness is created for the industrial use by adopting
favorable policies, a great amount of energy could be saved and income generation