Abstract:
Solar energy is an abundant renewable energy source and then worldwide
attention has paid to use this source for the electricity generation. The photovoltaic
(PV) effect is most widely utilized as direct conversion of sunlight into electricity in
Photovoltaic Cells (Solar Panels). When solar panels expose to the sunlight, the
temperature of the panels increases with the time and the efficiency of electricity
generation decreases. At present, many methods are employed to maintain the
solar panel temperature at a lower value; however, they are not effective. In the
present study, gravity assisted heat pipes (Thermosyphon) were employed to
reduce the cell surface temperature as heat pipes are known to be two-phase heat
transfer devices with extremely high effective thermal conductivity. An
appropriate refrigerant for the heat pipes was selected considering the average high
temperature of the solar panel and the ambient temperature. An array of heat pipes
was fabricated and fixed to the bottom surface of the solar panel. The dimensions of
the heat pipes used for the array are length 1 m and diameter i6 mm. For a single
heat pipe with the same dimensions, a performance test was conducted with 60 W
power input and the test results showed that the overall heat transfer coefficient at
the condenser section of the heat pipe was 104937.33 W/m'K. With the array of the
heat pipes fixed to the solar panel an outdoor tests were carried out to find
feasibility of maintaining a constant temperature of the panel for efficient electricity
generation.
