How Solar Panels and Solar Energy Work

You see them nowadays dotting roofs in neighborhoods, in clusters on roadside fields, atop vast industrial concepts when you’re landing at an airport. Solar panels are much more common today than they were even just five years ago. What’s going on with this new technology that can convert sunlight into energy?

New? Wait. The idea for solar panels emerged nearly 200 years ago when a scientist named Edmond Becquerel saw how certain materials sparked when hit by sunlight. This began our understanding of the photovoltaic (PV) effect, which, at the turn of the 20th century, could be captured by cells made of selenium. “Photo” means light, and “voltaic” means sun. By the 1950s, four percent of sunlight’s energy was being converted directly to electricity through PVs by scientists at Bell Labs.

We’ve been hoping for decades that solar can replace fossil fuels to heat our homes and businesses. There’s so much free electricity for the taking fro­m the sun! On a day with clear blue skies, the sun’s rays give off approximately 1,000 watts of energy per square meter of the planet’s surface. In a single hour, the sun transmits more energy to the earth’s surface than the world uses in a year.

If only we could capture all that wonderful sunshine and power our homes, businesses, and appliances! Unfortunately, we still have a gap in research to make the hope for 100% solar power a reality.

How does a PV cell work?

Electricity is the movement of electrons. Electrons create charge, which can then be put to use for power. Under the sun, a PV cell acts as a photosensitive diode. A diode is a semiconductor device that permits current to flow readily in one direction but restricts it from the opposite flow. Current is the movement of electricity along a conductor. With polarity, diodes have an anode or positive lead and a cathode or negative lead. Usually, flow occurs only with positive voltage to the anode. The photosensitive diode instantaneously converts light into electricity.

A PV cell has two layers. The top layer is made up of phosphorus-diffused silicon, and this layer carries free electrons. Free electrons are non-anchored particles with negative charges. The bottom layer is thick and boron doped. Doping is a process of adding impurities to intrinsic semiconductors to alter their properties. Boron is the p-type dopant of choice for silicon integrated circuit production because it diffuses at a rate that makes junction depths easily controllable. The term p-type refers to the positive charge of the hole. Since this bottom boron layer contains holes, or absences of free-moving electrons, the two layers have an explicit electronic imbalance.

Once the cell is exposed to sunlight, the fun begins. Photons inundate and penetrate the cell, activating electrons. The electrons, in turn, get disengaged within both silicon layers. All of a sudden, the free electrons on one side see openings on the other side, and there’s a furious rush to fill them. Some of the electrons from the bottom layer shoot to the cell’s upper section, stream into the metal contacts as electricity, and circulate throughout. A closed loop or circuit results when the electrons surge back into the cell through the solid contact layer at the bottom.

We shall be coming up with our youtube channels very soon to show us some videos on how to completely install your solar system. Please share your comments...