How It Works
Solar energy is the energy we acquire from the sun. Millions of years before humans realized the sun's potential as a renewable energy source, plants were using the sun's energy to convert carbon dioxide and water into sugars to eat. This process is called photosynthesis. Today, we have tried to copy plants by creating something called photovoltaic (PV) cells. These man-made cells are comprised of semiconductors, which are materials that are able to absorb light energy. The most commonly used semiconductor today is silicon because it is, so far, the most cost-effective material. The silicon absorbs a portion of the energy from the light that shines down on it, electrons are suddenly knocked free and are channeled to flow in the same direction by electric fields within the PV cell. On both the top and bottom of the silicon, metal contacts are placed and, through these contacts, the solar energy is extracted and stored.
Solar energy is used for a variety of different things but the ones that you are most familiar with are solar-powered calculators, solar-heated
Did U Know?
- Solar energy is measured in kilowatt-hours. One kilowatt hour (kWh) is the amount of energy needed to burn a 100 watt light bulb for 10 hours.
- Enough sunlight falls to Earth every hour to meet the world's energy demands for an entire year - the trick is learning how to extract that energy in a cost-effective way.
- Approximately 10,000 homes in the United States are run entirely on solar power.
- Solar energy can even be used to cook food!