Basics Applications
Applications
What are the Different Types of Solar Applications?
Solar applications range from the very simple garden light to the central power station supplying many megawatts of power. The two basic types of solar applications are grid-connected and stand-alone. Grid-connected systems are connected to the utility grid. Stand-alone systems are not connected to the utility grid and normally use a battery bank.
Applications include water pumping and numerous battery systems for houses, cabins, RVs, boats, signboards, marine navigation, traffic signs, garden lights, fountain pumps, and more. Anytime electricity is needed in a remote location, solar is a logical choice. Satellites are the prime example. Grid-connected solar systems can now be cost competitive with the utility company. As the cost continues to come down, more and more grid-connected solar sytems will be installed.
More information about different applications is in the Solar Basics book.
What is a Grid-Connected Solar System?
Grid-connected systems use an inverter to convert the direct current (DC) electricity produced by the solar array to the alternating current (AC) used by the utility grid. When the sun is shining and making electricity, energy is flowing into the grid, running the meter backwards. When it is dark or cloudy and the house or business is using more electricity than the solar system is producing, the meter runs in the normal direction. The net effect is elimination or reduction of the electricity bill. The utility acts like a battery. The excess energy is used by other houses and businesses in the area. This is called net metering and is allowed by most utility companies, but not all. Check with your local utility before installing this type of system.
More information about grid-connected systems is in the book Solar Basics. Design examples for grid-connected systems are in the Solar Design book.
What is a Stand-Alone Solar System?
Stand-alone systems use a battery to store energy. When the sun is not shining or it is cloudy, the battery supplies the loads, either DC or AC or both. Some stand-alone systems use the power directly without using batteries. An example is a directly connected water pumping system. Charge controllers are used to control the battery charging. Inverters are used to convert the DC if AC loads are used. Battery system are more expensive than grid-connected systems, but still lower cost than running a generator constantly. A standby generator or wind turbine can lower the overall cost of the total system because the solar system doesn't have to be as large and the generator is not running constantly.
More information about stand-alone systems is in the Solar Basics book. Design examples for stand-alone systems are in the Solar Design book.