Solar How To
In this article, I am going to discuss what each piece of a solar power system does, and what role the component plays in the system. Every piece handles a particular job, though you don’t have to include every part in every solar system. A typical solar power system produces electricity, stores the electricity in batteries for later use and then changes the Direct Current electricity from the battery to the same type of AC electricity that comes from the wall sockets in your house.
Solar Panels
The first part of a solar power system is the solar panels, which produce electricity using energy from the sun. The panel has a layer of silicon. When photons from sunlight strike the silicon, they knock loose electrons. The electrons are sent through wires and become electricity. A solar panel is composed of many solar cells, each of which generates about half a volt. By putting together the correct number of solar cells, any voltage you need can be generated. You can actually build your own solar panel and produce your own free electricity fairly cheaply and easily. To read more about how to build your own solar panel, check out DIY Solar Panel
Charge Controller
The electricity is used by the charge controller to charge the batteries. The voltage going to the battery needs to be in a certain range – not too high and not too low – and the charge controller makes sure the voltage stays in this range. In order to make sure that the batteries don’t overcharge it also gradually lowers the power sent to the batteries. Every once in a while after the batteries are fully charge, it will also “top off” the batteries to make sure they batteries stay fully charged. For more information about charge controllers, see All About Solar Charge Controllers
Batteries
Standard 12 volt batteries like you find in your car are used in most solar systems. The most common type are sealed lead acid. This type of battery is rugged, easy to find and cheap. Weight is the only real downside, but since you aren’t going to be moving the batteries around, it isn’t really much of a problem. You can often obtain surplus batteries from places like computer UPS systems for very cheap or even free.
Power Inverter
The batteries store and put out 12v Direct Current (DC), but the appliances in your house use 120v Alternating Current (AC). A power inverter converts the 12v DC power into 120v AC so you can use the electricity to power regular appliances. There are two types of power inverter: Modified Sine Wave (MSW) and True Sine Wave (TSW). MSW is not as good as TSW because TSW exactly matches the electricity that comes out of the the wall sockets in your house. It is preferable to use TSW over MSW becuase TSW more closely matches the electricy that comes from the grid. A TSW inverter will cost more than an MSW inverter, but it is generally a better choice in the long run.
Complete Solar Power System
Now let’s put all the parts together into a complete solar system. You generally mount the solar panels on the roof. Wires are used to connect the solar panels together and then send the electricity to the charge controller. The power coming from the solar panels is then conditioned by the charge controller and used to charge the batteries. The batteries are charged all day while sunlight is hitting the solar panels. All day, while sunlight is striking the solar panels, the batteries store the power generated by the panels. The DC electricity from the batteries is converted into the standard 120v AC electricity that your appliances are used to by the power inverter. A system like this can be small enough to power only a single appliance, or big enough to supply power to your whole house.
If you’re interested in how much it would cost for enough solar panels to power your whole house, see this guide to Solar Panel Cost
