How To Improve Solar PV Panels` Efficiency: [Measures]

     Solar Photovoltaic panels use the principles of Photovoltaics to convert light energy available in the form of photons from the Sun into electrical energy. As it is well known that this phenomenon occurs due to the semi-conductor electrons passing the required energy gap width in the cell, solar cells have the potential to degrade with their increasing life span. External factors like unfavorable weather conditions and physical wear and tear cause the degradation of PV panels. While the factors mainly affecting the solar panel efficiency is a common daily usage are soiling on the PV panels and high ambient temperature conditions. Considering the bad weather conditions and over-exposure to UV rays, solar cells in the panels degrade about 0.5% to 1% every year. By using various techniques, the solar panel`s power output can be boosted as well as the cell degradation rate can be slowed down.

Firstly, let`s delve into the soiling factors that plunge the panel efficiency on a daily basis.

    Soiling on PV panels is a common conditional effect that the PV panels are exposed to, as the panels are placed outside under the exposure of heat and wind. The wind creates a dust layer over the PV panel cells that obstructs the solar irradiance over the modules. These solar rays are dissipated, blocked, or reflected with a change of path that results in the low efficiency of PV panels. The solar cells' performance will be lower as low heat will be produced but also, the excess heat lost by the solar cells will be retained and used with help of dust particles as they are transparent and they can reflect back sunlight. However, the blockage of heat reaching the cells is an issue as low heat reaches directly to the cell, hence the surface temperature of the PV module will be less and the soiling will definitely affect the cooling process by air and also lower the efficiency.

    A basic solution to this problem can be the cleaning of solar panels. PV panels can be washed with water or wiped regularly as a measure to maintain the daily power output rates. This can result in exponentially increasing the power generation on a daily basis and also maintain the temperature range for solar cells up to an extent.

    Another method for increasing the efficiency of solar cells is the application of a layer of oil on the glass case of the PV panel. This kind of setup with a glass case will protect the PV panel from unfavorable weather conditions, as well as increase the solar transmissivity by the application of oil on its inner enclosed surface. The use of mineral oils has proven more efficient for this purpose compared to the use of the engine or brake oil available in the market. A 1 mm thick layer of Labovac oil on the glass case can improve the solar transmissivity which subsequently increases the solar panel`s power output by 15 to 18%.

    The only demerit of using oil to increase the solar panel efficiency is that it tends to raise the working temperature of PV panels. This may result in a high working temperature range which affects the cell lifespan. If the correct working temperature range is maintained by the fabrication of a simple cooling system, this method can be used without any risk factors.

    As stated above, introducing a cooling system for PV panels is a great technique to maintain the working temperature of PV panels. This not only results in the high efficiency of solar cells but also acts as a good measure for elongating the cell life.

    

    Such cooling systems are under research and there are many simple and complex methods used in the cooling PV panels. They can be classified as under:

1. Active cooling methods:

1.1  Active cooling of PV panels by air

1.2 Active cooling of PV panels by water

1.3 Cooling of PV panels by nanofluids

1.4 Cooling of PV panels using a heat exchanger

1.5 Active Heat Sink using Thermoelectric Module (TEM)

2. Passive cooling methods:

2.1 Passive cooling of PV panels by air

2.2  Passive cooling of PV panels by water

2.3 Passive cooled PVT system by phase change materials

2.4 Radiative cooling

"I will further discuss a basic passive cooling system for PV panels in my upcoming blog that uses water as the cooling medium. This system was fabricated by our team for an experimental study, and I will also discuss the power output results with and without the cooling system that we used."