Introduction To Solar Power Generation

Photovoltaic Solar Panels

Photovoltaics (PV) literally means "light-electricity," and is the process of converting sunlight into electricity. The term "photo" comes from the Greek word "phos" or light, and "volt" was derived from Volta (1745-1827), a pioneer in the study of electricity.

How does it work?

When some materials are exposed to sunlight, they release small amounts of electricity giving off what is known as the "photovoltaic effect." Sunlight is composed of photons, or particles of solar energy that contain various amounts of energy corresponding to the different wavelengths of the solar spectrum. When photons strike a PV cell, the energy of the photon is transferred to an electron in a cell's atom. The cell is made of a semiconductor material.

With its newfound energy, the electron escapes from its normal position on the atom and becomes part of the current in an electrical circuit. When this happens, the electron creates a "hole." Special electrical properties of the PV cell, specifically a built-in electric field, provide voltage that drives the current through an external load, such as a light bulb, a hairdryer or a television set.

The components of PV systems

Photovoltaic modules are the basic building blocks of solar electric power systems. PV modules can be made from several different materials, which vary in cost and conversion efficiency. Modules are combined to create panels. Panels are combined to form arrays. Solar electric power systems may also have batteries, charge controllers, and inverters, which convert the direct current generated by PV system into an alternating current, the type of electricity sold by utilities and required to run most appliances and electronic devices.

Types of Solar Modules

There are two major categories of solar modules, Crystalline and Thin Films. There are a couple types of each and each has its positive and negative factors.