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How to choose a solar panel?

Solar panel logic is simple, light hits the panel and creates an electric field. The generated electricity

flows to the edge of the panel, and into a wire. The wire brings the electricity to the controller and inverter, where it is transformed from DC electricity to AC, which is used to power your regular home devices.

If you plan to do a DIY project then understanding different parameters and specifications is sometimes challenging? So what to look out for and how to choose solar panels for your DIY project?

As a side note, please make sure to find out if you need a permits before you can start building or installing the solar energy system. You most likely need a permit and audit if you want to connect your solar system to the national grid system and maybe interested in selling your excess energy production.

Solar panel parameters and specification

Measure and size

Size and Weight: The size and weight of a solar panel are important if you have limited space or need to install the panel on a roof. Make sure the panel is the right size and weight for your installation location.

Power, voltage, current and efficiency

Power output

This is measured in watts and indicates the amount of electricity the panel can produce under standard test conditions (STC). The power output of a solar panel can vary depending on factors such as the amount of sunlight it receives and the temperature of the panel.

For more information about STC please see the post: STC, PTC, NOCT: What do they mean and how to use them?


Voltage is important because it determines the maximum power point (MPP) of the panel – the point at which the panel is producing the maximum amount of power. For example, if a solar panel is connected to a battery or an inverter that requires a certain voltage to operate, it is important to select a panel with a voltage that matches or is close to the required voltage. This will allow the panel to operate at its MPP and provide the maximum power output possible.

In addition, the voltage output of a solar panel is also important for system design and wiring. The voltage output of the panels needs to be matched with the voltage requirements of the system and the wiring needs to be designed to accommodate the voltage and current of the panels.


Current is the flow of electric charge, and is measured in amperes (A). Current is important because it affects the overall power output of the panel.


Efficiency is the measure of the amount of sunlight that a solar panel can convert into usable electricity. Higher efficiency panels will produce more electricity in the same amount of sunlight than lower efficiency panels.
Solar panel efficiency is expressed as a percentage, and is calculated by dividing the amount of electrical power produced by the panel by the amount of sunlight it receives. Solar panel efficiency can be affected by factors such as temperature, shading, and the angle of the panel relative to the sun.

Type of solar cells

There are different types of solar cells, each with its own advantages and disadvantages. Some common types include monocrystalline, polycrystalline, and thin-film solar cells. Consider the efficiency, durability, and cost of each type when choosing a solar panel.

Temperature Coefficient

This is a coefficient of how much a solar panel’s efficiency will decrease as the temperature rises. Choose a panel with a low temperature coefficient for better performance in hot climates.


A warranty is important because it provides protection against defects and performance issues. Choose a solar panel with a warranty that covers both materials and workmanship.