
and reliable that could be used to increase the
electrical efficiency of the panels.
There are three types of cooling methods as
follows: the first one is the universal smart window
made of a material that controls the light and heats
passing through it. This window is set in 3 modes by
applying a small amount of voltage. It is switched
into a cool mode to allow the light to pass through
the glass and prevent the heat from passing, thereby
protecting solar cells from high temperatures and
improving their efficiency, [9]. The second is air
channel/chimney which is an effective passive
solution that utilizes a channel or chimney to force
the natural air to pass and circulate through and
dissipate the heat, [10]. The third is the radiator
which is a heat exchanger that transfers the heat
from the fluid inside to the air outside, it controls
the temperature used by water flow control and air
flow control.
2 Design Concept and Conditions
A passive method is adopted as a new idea to
enhance the efficiency as well as to improve the
performance by cooling the PV panel. An air
channel and chimney method are selected to be
utilized for the PV cooling system, which is simple,
effective, and cheap. The main idea of our solution
depends on the airflow mechanism. Many factors
affect air flows such as air temperature, pressure,
density, and the area that air flows through. The
pressure difference can let the air flow from one
area to another from high pressure to low. This
factor (pressure difference) is directly proportional
to air quantity, when the difference increases, the
amount of airflow increases too. When the hot/warm
air inside the air channel has lower pressure than the
cold air which is outside, the cold air transfers to the
air channel. Then, the air rises to the upper level
when it becomes warm since it has a lower density
than the cold air and increases the positive pressure
at the chimney. In positive pressure, the inside air
pressure (hot air) has higher pressure which is
pushed out of the chimney, [11].
This solution works as the air enters through the
air channel and leaves from the chimney which is in
the middle of the panel. Hotter air is lighter, so it
leaves the solar panel through the chimney. The
cold air will remain in and cool the panel. Which
will lead to a decrease in the solar panel
temperature. Another way to force more hot air to
leave the panel is to increase the height of the
chimney. The design is selected and evaluated to
have a good cooling system with the highest
efficiency. Furthermore, it can be improved by
having two air channels above and below the PV
module instead of one channel for several reasons.
There are some factors to be considered in the
design which affect the PV performance such as the
rate of air flow, and the position of channels (placed
above or under the PV panel). On the other hand, to
increase the efficiency, the below air channel could
be another entrance for air to cool the PV. It is
suggested to have another air channel under the PV
with an air flow channel to cool the PV from the
below side too. So, the air could be delivered from
above, below, or on both sides of a PV. The
design consists of one air inlet, one air channel
placed above the PV panel, one air chimney, and an
air flow channel that is placed under the surface of
the panel to reduce the temperature and as a result,
increase the efficiency of the panel. Hence, two air
channels are placed from both sides, above and
under the PV panel as shown in Fig. 1. Adding those
two channels reduces the temperature more than
installing only one air channel. Thus, the efficiency
will be enhanced.
Fig. 1: The design sketch
This passive cooling technique design is mainly
based on passive air channels and a chimney and
does not need any energy for operation with low
cost since only natural air is needed to decrease the
temperature of the PV panel which in turn will
increase the efficiency. For monitoring and
controlling purposes, temperature sensors are used
that help to read the temperature of the panel.
The material of the design is very important and
should be selected with properties that do not affect
the performance or the reliability requirements. In
addition, the material should be easy to manufacture
and design. A list of criteria is developed for
material selection. as follows: cost, availability,
weight, and manufacturing. The focus is on the cost
and the availability where the selection of the
components will be the least cost to make the
system cost-effective. For the channel’s material,
WSEAS TRANSACTIONS on POWER SYSTEMS
DOI: 10.37394/232016.2023.18.2