People have a lot of misconceptions about solar, often due to misleading marketing tactics by solar companies. If you are going solar, you should know the facts so you have realistic expectations.
Solar can save you money. A standard grid-tied system feeds energy to your house so you don’t have to buy as much electricity from the electric company. But this is generally where it stops. Solar will not make extra money for you. Unless you are lucky enough to live in a place where you can sell Renewable Energy Credits (RECs), you are limited to saving what you normally spend on electricity. If you generate most of the electricity you use, you can reduce your electric bill to almost nothing. But if you generate more electricity than you use, you will get little or nothing back from the electric company for the excess kilowatt hours.
Solar can be used to provide backup power during a power outage, but this functionality typically costs extra and/or is very limited. The least expensive way to get back up power from solar is to use an SMA inverter that can be installed with a special power outlet that works during power outages. The limitations are that it only provides power when the sun is out and even then, it is only 1800 watts. So, if the power goes out at night or during a thunderstorm, that outlet won’t be much help until you have sun again. But, once you have sun, you will be able to power small devices, charge your phone or laptop and possibly even run your refrigerator.
Beyond that special outlet, solar backup systems with batteries are available but they are pricey. They generally start around $7,000 for a small one. The more appliances you want to run during the power outage, the more the system will cost. It is usually cheaper and less limiting to purchase a backup generator that runs on diesel or propane.
Solar can be used to run remote devices like well pumps and signal repeating towers. These systems can be set up two different ways. One way is to install solar directly to the device and when the sun is out, the device will work, when it is cloudy or dark, the device will not work. The other way is to install the solar with a battery system that stores the power when the sun is out so you can run the device any time. These types of systems are great options to run something that is too far away from the power grid.
But, if everything you want to run is near your main service panel, you are better off installing a standard grid-tied solar system. For example, if you installed a solar power system that was only connected to a well pump, it is very possible that the solar would generate more power than the well pump needed. If the well pump and solar system are isolated, that extra energy is just wasted. If that well pump was close enough that you can run grid power to it, then you can tie it in with the rest of the house on the main service panel, install the same amount of solar, and the excess solar power not needed by the well pump would get used by other devices or feed to the grid for credits. Better yet, why not install a larger solar power system that can offset all your electricity needs and save even more on your electric bill?