Really? UNIMAID Final Year Student Constructs A Solar Water Heater (See Photo)

A UNIMAID final year student ,
Muhammad jaafar from the department
of physics has constructed a solar water
heater, a water heater utilizing the
sunlight to produce a hot water for
domestic hot water demand.
The solar water constructed from a
locally available materials to
minimize cost , made for simplicity of
installation, reduce electricity bill and
durability to meet domestic hot water
demand.
According to him , the solar water
heater can heat water up to 70°C
which sufficient for domestic water
demand ; in his word “A solar water
heating system for domestic use has
been designed and constructed using
locally available materials. Solar
energy is received by a flat-plate
collector consisting of a thin absorber
plate, integrated with grids of fluid
carrying tubes, and placed in an
insulated casing with a transparent
glass cover having a water tank
integrated in the system. The
radiation emitted by the absorber
plate cannot escape through the glass,
thus increasing its temperature. On
the principle of thermosyphon, hot
water is pushed through the collector
and rises by natural convection to the
water storage tank and cold water
from the water tank simultaneously
descends to the bottom header of the
collector by gravity pull.
The water gets heated and flows into
a storage tank through thermosyphon
principle. The system was tested and
Maximum fluid output temperature
and the collector temperature, of 75°C
and 70°C respectively, were obtained
on a sunny day. This solar water
heating system finds useful
application and acts as a renewable
energy resource in regions where
there is abundant and consistent
sunlight.”
He further explained the working
principle of the solar water heater , in
his words ” Principle of operation of a
flat-plate solar water heater, The solar
radiation passes through the glass in
front of the absorber plate and strikes
the flat black surface of the absorber
plate where the solar energy is
absorbed as heat (i.e. by increasing
the internal energy).
Figure 2 solar water heater showing
the flat plate solar collector exposed
to sunlight
This causes the flat-plate collector to
become very hot, and so the water
contained in the pipes bounded to the
plate also absorb the heat by
conduction. The water inside the
tubes (risers/headers) expands and so
becomes less dense than the cold
water from the storage cylinder. On
the principle of thermosyphon, hot
water is pushed through the collector
and rises by natural convection to the
water storage tank and cold water
from the water tank simultaneously
descends to the bottom header of the
collector by gravity pull.
Therefore, there is circulation as a
result of an increase in temperature
and volume of the warmer water to
the water storage tank. The
circulation continues as hot water
goes out, while cold water comes in.”
When asked what are advantages of
this solar water heater , he said Solar
water heaters based on thermosyphon
principle have the following
advantages: simplicity and low cost,
requires no electrical supply, need no
controller or pump, easy to install,
can withstand mild sub-zero
temperature, is reliable and long-
lasting since there are no moving
parts, scalable (several collectors can
be connected in parallel to increase
hot water supply), is easy to build and
operate, no fuel cost, provides heated
water of about 70 °C or within the
range, and is portable.
They, however, have the following
disadvantages: cannot withstand
mains pressure, cannot give higher
temperature water, are affected by
weather conditions, very useful only
during the dry season, and can be
more practicable and useful in the
sunny regions.”
when asked what is the significance
of this project he said “ it designed to
address challenges and threat pose by
the use of fossil fuels ; such as the
increase in oil demand accompanied
with oil price rise, political crises in
the world oil deports, depletion of oil
reserve, reduced availability of fossil
fuel, and other harmful effect
attributed to the use of hydrocarbons
such as, oil spillage, aquatic water
pollution, agricultural soil
degradation, ozone layer depletion,
health hazards, and relatively tangible
problems of aesthetics to problems of
environmental conservation,
greenhouse effect, and global climate
change and other air pollution issues
caused mainly by burning of these
hydrocarbon as a source of heat
energy .
The unavailability of electricity in
most of our rural area, its high cost
and inadequacy has led to the drive
to use environmentally friendly,
cheap and renewable alternative
sources of heat energy to eliminate or
minimize these negative effects.
Presently, solar and other alternative
energy resources are being harnessed
for various applications such as
power generation, air-conditioning,
space heating, domestic hot water
system, etc. “