You need to find out about solar power systems before you can decide if they are something that you want to invest your money in. Rather than just going for the latest trend, you want to do your research, and see how you can best benefit from the technology. Besides, when you have your solar power system, you want to be able to explain to your friends how it works! This article is for you.
There are some different options to finding the right solar power system for your house, but they all tend to use the same components. First, you have to understand that your house functions on AC (alternating current) electricity, but batteries and solar panels produce DC (direct current) electricity. This means that you can’t just connect the solar panels or any batteries to your house wiring, it just wouldn’t work and would be dangerous.
The fundamental element to make the DC electricity that you have into the AC electricity that you want is called an inverter. These are available in various sizes, depending how much electricity they have to deal with. You will have to use one that is approved for the function, if you are keeping a connection to the utility – you see, alternating current alternates the electricity flow, and when you produce your own AC, and connect to the utility grid, you have to be sure that the alternating is in time, or synchronized, from both sources. It would be dangerous if it wasn’t, and could cause all sorts of problems.
The Solar Array
Another essential element of your solar power system is the array of solar panels that you will be using. Often mounted on your roof, they can take various forms, and are usually dark blue or black, covered with glass, and measure about five feet long by just over two feet wide. You will have several of these, side-by-side, connected together electrically. You need to coordinate the voltage from these with the rest of the equipment. Each panel may be a nominal 12 volts or 24 volts, and they can be wired together to make a multiple of these, such as 48 volts, to suit the rest of your system.
The other components of the system may or may not be needed, depending on your actual arrangement.
If you want to store power at your house, you will need batteries. Most people are familiar with lead-acid batteries, such as you have in your car, and this is one type that is used with a solar power system. The actual batteries you use will be a little different, as they need to be deep cycle batteries, which work better for the conditions. Deep cycle batteries are used in RVs and boats, and can take a steady discharge better than an auto battery, which is built more for the large starting current of a car. They will need maintenance every few months, but the sealed type of battery which is also available doesn’t. It is, however, more expensive. Depending on your power storage requirements, you will need several batteries.
Along with the batteries, you need a way to charge them. You can’t just connect them to a power supply, as they will overcharge and be ruined. For this purpose, you need a charge controller, which senses how the batteries are doing, and sends the right amount of power their way.
Your system will have some ancillary items, such as switches or disconnects, and some metering. The items described above are the pieces of equipment that are necessary for the basic function of the solar power system, and they can be arranged in various ways.
Different types of Solar Power Systems
The simplest system is the “Grid Intertied Solar Without Batteries” seen above. This is a basic net metering arrangement, where the solar system may put power into the grid when you don’t need it, and you will use grid power when the solar system is not providing enough capacity. All you need is the panels and the inverter to produce AC power, as shown, and the metering on the utility connection measures which way and how much electricity flows.
The next solar power system builds on this system, adding batteries for energy storage. This is the sort of system you would have if you wanted protection from losing your power supply to the house, and this is called “Grid Intertied Solar With Battery Backup”. Note how the solar panel output is routed to the charge controller, which controls how much power the batteries can take. The panels are not directly connected into the inverter, as in the first system, but the batteries provide a buffer for the power. The DC from the battery bank goes to the inverter, and makes AC electricity, as in the first case. Note also that there is an arrow both ways between the batteries and the inverter – this denotes that power from the grid can charge the batteries, if needed.
Finall,y we go back to the previous solar and battery configuration, but without any connection to the utility grid. The “Off-Grid Solar” system shows an arrangement that would allow you to run your house even if you didn’t have a supply from your local utility company. This would also be suitable for your weekend cabin in the mountains. It functions in the same way as the second scheme, and shown in this case is an optional generator in place of the utility connection. While not completely necessary, if you want your power supply to be reliable you need to have an alternative way of generating power. This covers you for long periods of overcast weather, and also helps avoid having more batteries to carry you over those times.