Sunlight is a renewable and limitless energy source. It can be regarded as a dependable source because the amount of energy that can be harnessed to generate electricity is from the sun. Although it is limited by the winter season and cloudy weather – these reduce their effectiveness.
Solar cells are the frameworks of solar panels. Multiple solar cells are positioned in a way that makes up solar panels. Solar panels turn energy from the sun’s rays straight into useful energy that can be used in homes and businesses. There are two main types: solar thermal and photovoltaic (PV)
Solar thermal panels use the sun’s energy to heat water that can be used in washing and heating. PV panels use the photovoltaic effect to turn the sun’s energy directly into electricity, which can boost or replace a building’s usual supply of electricity.
Solar panels generate direct current (DC) electricity when exposed to sunlight via the photovoltaic effect. A simple clarification is that the photons from sunlight are consumed and retained by a semiconductor material – silicon.
The negative electric charged electrons are knocked loose from their atoms, and flow from the negative side to the positive side to reposition with available holes there. This creates a direct current flow. This flow of electrons can then be used to either directly power a DC device, like a pump or a fan, it can be used to charge a battery bank, or it can be inverted to alternating current (AC) power to use in your home.
A solar cell generates about ½ volt. It is a section of a silicon.
Multiple solar cells are wired together in series to create higher voltage, creating a solar module, commonly referred to as a solar panel. A typical 12 Volt (V) solar panel has 36 cells in series.
The more solar cells wired in series, the higher the voltage of the solar panel.
During daylight hours, the panels on the roof collect the energy from the sun and feeds it to an inverter. This happens even on cloudy days.
Any excess electricity that is not used is fed into the National Grid. Power companies pay for the surplus energy in the form of a credit on your bill.
Notes
1. Source: How do solar panels work
Oyin Okusanya
Outreach and Marketing Fellow
oyin@resonant.energy
Boston Affordable Energy Coalition 