Solar panels use the light energy produced from sunlight to generate electricity, this is through a system called the photovoltaic effect; this involves voltage being created in a material upon exposure to electro-magnetic radiation. Photovoltaic effect works by generating electrons and transfers them from one material to another resulting in a build up of voltage between two electrodes.

Depending on how the photovoltaic is constructed it can cover a range of frequencies of light and produce electricity but can’t always cover the entire solar spectrum, so a lot of incident sunlight energy is wasted.

Most modules use wafer based crystalline silicon cells or sometimes thin film cells based on silicon or cadmium telluride.

Crystalline silicon is commonly used in the wafer form of photovoltaic modules and is derived from silicon which is a commonly used semi conductor.

To achieve the desired output voltage the electrical connections are made in series or if a desired amount of current is required they are connected in parallel.

To avoid overheating of the cells in case of partial shading diodes are included, it is always desirable to reduce heating to increase operational efficiency, although few modules incorporate any design features to decrease temperature they do include good ventilation.

The radiation used is obviously sunlight which is why we call them solar cells as they use solar energy.