Tuesday, May 21, 2013

How Do Solar Power Systems Work?

By Mauro Small
Solar power is the cleanest and most practical form of renewable energy available. It can be used to generate electricity or to heat hot water tanks and swimming pools. The technology is improving every year, making solar power systems smaller and more efficient. Solar energy is collected using solar panels, where radiant heat is converted into energy to produce electricity.
How Solar Panels Work
A solar power system consists of solar panels, inverters, batteries, and a charge controller. Solar panels are connected assemblies of several photovoltaic cells. Each individual cell is coated with a positive and negative layer to create an electric field. As photons from the sun, or sunlight energy particles, enter a cell, they allow the electrons in each cell to become free. The free electrons flow through a wire connected to the photovoltaic cell, and thus this flow of electrons becomes electricity. The most important part when installing solar panels is to arrange them at the proper angle for maximum solar exposure.
Solar Power Inverter
A solar power inverter is an electrical device that changes direct current (DC) from the photovoltaic cells into alternating current (AC) that is used inside a home or building. A solar inverter can be fed directly into the electrical grid or connected to the photovoltaic system. Solar inverters can work with transformers and control circuits to get any desired voltage and frequency.
Solar Power Battery
Solar power batteries store the energy harvested from solar panels. This energy can then be used at night or when energy from the sun is not available. Lead-acid batteries offer the best performance and are the ones most commonly used in solar power systems because of their relative good efficiency and lower price. A collection of batteries used in a solar system is called a battery bank. A battery bank should be sized to be capable of storing power for 5 days of operation without requiring energy from the sun.
Solar Power Charge Controller
A solar power charge controller is used to prolong the life of the battery bank. It accomplishes this by preventing the battery from overcharging. The controller monitors the battery voltage and reduces the current when the voltage increases. When the voltage drops, the controller allows the current to increase so that it can charge the battery again. Controllers are selected by how much current they can handle and it is a good idea to select an over-sized controller to allow for future expansions of your photovoltaic system.
Solar power systems are becoming more accessible to the public due to technological advances and greater efficiency for all of its systems components. The solar energy we collect is free and is something that we should strive to take advantage of since it greatly reduces our electricity bills and help to save the planet.
Mauro Small writes for Go Green Academy, an information website on topics related to energy efficiency, climate change and sustainability.