What Is Solar Energy?
What Are Photovoltaics?
Introduction to Solar Energy
We have always used the energy of the sun as far back as humans have existed on earth.
We understand today, that the sun is simply our nearest star.
Without it, life would not exist on earth. We use the sun's energy every day in various ways.
When we hang laundry outside to dry in the sun, we are utilizing the sun's heat to do work - drying our clothes.
Plant life uses the sun's light to make food. Then animals eat plants for food.
Decaying plants and organisms from hundreds of millions of years ago produced the coal, oil and natural gas that we use today.
So, a fossil fuel is really sunlight stored millions and millions of years ago.
Indirectly, the sun and other stars are responsible for all our energy.
Even nuclear energy comes from a star on account of the uranium atoms used in nuclear energy were created in the fury of a nova - a star exploding.
Solar Cells or Photovoltaic Energy
Solar cells are small, square-shaped panel semiconductors created from silicon and other conductive materials. They are produced in thin film layers. When sunlight strikes a solar cell, chemical reactions release electrons, generating an electric current. Solar cells are also called photovoltaic cells, or PV cells for short, and can be found on many small appliances, like calculators.
Individual PV cells are put together in a PV module and the modules are grouped together in an array. Some of the arrays are set on special tracking devices to follow the sun all day long.
The electrical energy from solar cells can then be utilized directly. It can be utilized in a home for lights and appliances. It can be utilized in a business. Solar energy can be stored in electric batteries to light a roadside billboard at night. Or the energy can be stored in an electric battery for an emergency roadside cellular telephone when no telephone wires are around.
There are two PV markets. Off-grid systems are used where the cost of a PV system is less expensive than stringing electrical power lines long distances from the local utility. Grid-connected PV energy systems usually cannot compete directly with the cost of utility-produced power. Because of state incentives and federal tax credits, many people are considering grid-connected PV energy systems. If the PV energy system provides more power than the home or business uses, additional electricity is fed back into the grid for other people to use. This effectively spins an electricity meter in reverse in what is known as "net metering."
Incentives offered to homeowners and small businesses is helping to develop a more robust PV industry in the USA. Additionally, growing demand for PV cells, along with competition, can help drive down the per watt price of PV cells.
Photovoltaics or solar cells can be purchased in two formats: as a stand-alone module that is fastened to your roof or on a separate system, or using integrated roofing materials with dual functions - that as a regular roofing shingle and as a solar cell generating electricity.
Solar Energy Systems do not produce polluting air emissions or water effluents, therefore solar PV systems are prime candidates for supplying electricity.