Sunlight - or a source of alternative energy , has been gaining momentum as a source of electricity. Most likely you’ve seen light powered calculators or sun panels on rooftops for heating homes. This same power can also be used to generate larger amounts of electricity. Instead of using fossil fuels, renewable power technologies use photovoltaic panels to convert sunlight directly into electricity. This process involves no moving parts. These systems can be very small (using only a few panels) or many panels can be connected together to construct large systems.

The sun powered panels are made of semiconducting materials similar to those used in computer chips. When sunlight is absorbed by these materials, the new energy knocks electrons loose from their atoms, allowing the electrons to flow through the material to produce electricity. This process of converting light (photons) to electricity (voltage) is called the photovoltaic effect. Knocked free, the electrons are forced by the electric fields within the PV cells to flow in a certain direction which is known as current. Because there are metal contacts on the top and the bottom of the PV cell, we can draw the current off to use externally. The electrical output from a single cell is small, therefore multiple cells are connected together to provide a more useful output. Cells connected in this way are encapsulated (usually behind glass) to form a weatherproof module or panel. These are called solar modules. The typical solar module has about 40 solar cells.

These electricity generating cells are typically combined into modules that hold about 40 cells; about 10 of these solar modules are mounted in solar arrays that can measure up to several meters on a side. These flat-plate PV arrays can be mounted at a fixed angle facing south, or they can be mounted on a tracking device that follows the sun, allowing them to capture the most sunlight over the course of a day. About 5 to 10 PV arrays can provide enough power for a household.

Because the electricity produced by PV or photovoltaic arrays is in the form of direct current(DC or common battery), if the electricity is supplied to the electric power grid, the arrays need to be coupled to an inverter which changes the direct current(DC) into alternating current (AC or household). Once converted to the appropriate voltage and frequency, the electricity can be supplied to the electric grid. Then we have alternative energy.