Step #2: Determine what do you want to do with the power and how to utilize it
If you are already served by a power company, it is considerably cheaper to purchase a “grid-tie” system. If you want to be totally independent of your energy company and/or you need electricity in a location that is not yet served by your energy company and it would be very expensive to connect, you will want to consider a “Battery Stand-Alone” system. A “Battery Back-up” system is a combination of the two systems, where batteries are used as a back up for a power outage in an emergency situation.
Grid-tie: You generate power during the day (while the sun is out) so if you’re producing more than you’re using, your meter will run backwards. Your energy company supplies the power you use at night, so your meter will run forwards. This push-pull will “net” at the end of the month with a balance either in the customer’s favor or in the electric company’s favor. In this dynamic, the power company acts as a huge energy storage device/battery.
Battery Stand-Alone: Along with the solar panels and support system, you will need to purchase batteries. Your solar panels charge the batteries and you then draw energy needed for your house from the batteries. You would need to determine all energy needs and make sure your system is large enough to acquire and store enough energy.
- Battery Back-Up: This is a hybrid system that is useful when power goes out. You can pre-determine which appliances should never be without energy, and then store that needed power. For example, you might have emergency back up for your refrigerator, computer, and 4 lights.