There are two basic types of solar panels. One kind makes electricity, the other kind generates heat. It's important to know which kind you need for the job you have in mind, because they are not interchangeable. But both kinds can save you money and help you live a greener lifestyle.
Solar thermal collectors use the sun's energy to heat water and other fluids, like oil. They typically use plastic tubing, hoses or coils in the panel. The liquid runs through the coils and is heated by the sun. These types of panels are ideal for heating swimming pools, spas, hot tubs and hot water for homes and businesses. They can also heat building interiors by using baseboard heating units and hot water flooring systems. Once they are installed, there is usually no need for additional heating fuels. But the systems usually require some kind of motorized pump to circulate the fluids.
Solar photovoltaic cells create DC (direct current) electricity. Most typically, they use semi-conductor material (silicon) in the panel, which interacts with sunlight to create electricity. The electricity then can be used to power computers and appliances, or the entire house, if you build the system big enough. The electricity is only generated from the panels during the day when they are interacting with direct sunlight.
In order to use a photovoltaic system at night or during cloudy days, the electricity must be stored in a battery storage system. You can use inexpensive lead-acid batteries (like you car uses), but you will need to make sure they are filled with distilled water in order to maintain their charge. You can also use more expensive batteries. Sealed AGM (absorbent glass mat) batteries don’t require maintenance to retain their charge. Gel batteries are good choices for cold climates because of their freeze-resistance.
Both the thermal collector and the photovoltaic systems typically use glass panels to encase their collection systems, and both require access to direct sunlight. The panels are ideally situated in a location that faces south and allows maximum exposure to sunlight during the entire day. They can be used anywhere to harness the sun's energy, but they are less effective in regions that typically have a lot of cloudy days throughout the year.
Even in mostly sunny regions, it’s always a good idea to add a backup generator to both kinds of solar panel system. Backup generators can be fueled with biodiesel to maintain your green lifestyle. And the generators can be used if your battery storage fails, or whenever there is an unexpected stretch of cloudy days.