In this article we will talk about how to get the maximum output power of a solar PV panel and the factors that affect its performance.
There are many factors that affects the performance of solar PV modules, here are some:
- Orientation (Azimuth and Tilt Angles)
- Temperature
- Soiling
- Shading
Orientation (Azimuth and Tilt Angles):
To get the maximum output power of a solar PV you need to make sure that the panel is exposed to maximum solar radiation by orienting the panel toward the sun. The angle between the incident sunrays and the panel surface must be 90 degree to have maximum incident solar power. So, move the panel right and left (Azimuth angle) and up and down (Tile angle).
Senario:
Assuming the sun position of a certain day is shown in the below diagram. We can notice how tilt angle of a panel can change the amount of the captured solar radiation. So, make sure to set the optimum tilt angle so that you get maximum output power.
Note:
- Sun position is changing from day to day and it depends on your location.
- The Sun is higher in the sky during summer that winter. Therefore the tilt angle of the panel should be lower in summer and higher in winter to capture more solar radiation.
- Since the sun is moving in the sky from east to west during the day, by moving the solar panel to follow the sun you can get the maximum solar power. But if you want to fix the panel in on direction, then always direct the panel toward south (for Northern Hemisphere locations) and toward north (for Southern Hemisphere locations).
Temperature
Solar (c-Si) PV panels efficiency and output power are affected by temperature. When the temperature of a solar panel increases, its efficiency will decrease and therefore its output will decrease too.
The output of most solar panels is measured under Standard Test Conditions (STC); this means a temperature of 25 degrees Celsius (77 degrees Fahrenheit). The maximum output power of a solar PV panel and its efficiency are measured at 77 degrees Fahrenheit. It the panel’s temperature gets cooler below 77 degrees Fahrenheit, its efficiency increases and output power increases.
Note:
- The hotter a panel gets, the less power it generates (efficiency down).
- The cooler a panel gets, the more power it generates (efficiency up).
To reduce the effects of heat, make sure to install your panels a few inches above the ground or roof so convective air flow can cool the panels.
Remember:
High temperatures have negative effects on Solar PV panels.
Soiling
Soiling is the accumulation of dust, dirt, pollen, bird droppings and even snow on the solar PV panels. The increase of the soiling at the surface of the panel will decrease its performance and increase the power loss, and therefore will decrease the output power. So, You need to make sure that the surface of your solar panels is always clean to get the maximum output power.
Warning
- Make sure to use a soft sponge or clot with pure water to clean your solar panels.
- Avoid hot water.
Shading
Shading of even one cell of PV panel will reduce its output power too low. In general, solar cells in a PV panel are connected in series, therefore all cells will produce power as low as the weakest cell. In some cases, this partial shading can cause the PV panel to produce zero power. These rules are applied on a series of solar PV panels that are connected in series.
Remember:
Always avoid partial shading from any obstacle such as trees.
