Photovoltaic Cells (Solar Panels) Devin Noyes
Contents Background How it Works Visual Current Applications Cost In the Future
Background The word photovoltaic comes from “photo,” meaning light, and “voltaic,” referring to producing electricity. A photovoltaic cell is a device that produces electricity directly from sunlight. The first practical solar cells where developed for space applications in the mid 1950’s because the builders of early space craft required an energy source that was reliable, long lasting and required no maintenance.
Monocrystalline vs. Multicrystalline Solar panels are made of either monocrystalline or multicrystalline cells. Mono cells are cut from a chunk of silicon that has been grown from a single crystal. These are more expensive and more efficient cells Multi cells are cut from a multifaceted silicon crystal. These are not as efficient in converting the suns rays.
How it Works PV cells consist of two layers of a semiconductor material, one p-type one n-type, sandwiched together forming a ‘pn junction’. When sunlight strikes the cell, the semiconducting material absorbs photons from the light. This frees electrons from one layer to another creating an electric current. This current is captured in the ‘pn junction’. This electricity generated and captured can then be stored in a charging system or converted and used.
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Current Applications Residential Homes Industrial Applications Vacation Houses Outer Space Water Pumping, Lighting, and Heating Central Power Systems Commercial Buildings Other Applications
Cost Mono Cells Multi Cells Thin Film Cells Cost for 20 Watts $159 $80 $305 Price/Watt $7.95 $4 $15.25 Efficiency 20%
In the Future PV cells are continuously getting more efficient and the cost of the cells themselves are steadily falling with increasing mass production. As costs fall over time hopefully solar cells become more common in every day applications. The more PV cells used lowers the amount of greenhouse gasses and other pollutants being produced.
The End Questions?