A Non-Technical Guide Introduction to Solar Power
There are four primary components to solar electric power systems. Known also as a "solar power system", they include solar panels, charge controllers, batteries and inverters. All of these components are necessary to have a functioning solar electric (PV or solar power) system.
The solar panel is the cornerstone of the solar electric power system. The solar panel(s) acts as a battery charger. When several solar modules are wired together a "solar array" is created. The size of the solar array determines the amount of power that will be produced by the system.
A charge controller is an important system component that regulates the voltage generated from your renewable energy system and properly maintains your batteries. It protects your batteries from being over and under charged, and ensures maximum battery life.
Batteries are used to store the energy that is created by your solar power system. Typically, loads receive their power from batteries instead of directly from the output of a solar panel. A solar panel produces a high voltage that will damage electronics if loads are powered directly. Batteries will provide you with the energy you need at night.
The last major component is the Inverter. The inverter converts the DC (Direct Current) energy stored in your batteries and turns it into the AC (Alternating Current) power you use in your home. Inverters are rated by wattage and the quality of their output. You can use a 50 watt inverter that plugs into your car 12 volt outlet to power a computer, or you could have a 4000 to 1,000 watt inverter system that powers your home.
These major components can be put together in many different ways. Minor components like wire, disconnects,circuit breakers, and fuses are also needed for a complete system.
Solar Power System Configurations
Stand Alone or Off-Grid Systems
Solar---Charge Controller---Battery---Inverter---AC Loads
Solar---Charge Controller---Battery---DC Loads
A stand-alone solar power system is a system that is not connected to the main electric utility grid. Stand-alone solar electric systems are used when utility power is not present or is too costly to bring in from the nearest access point on the grid. If you have a out-building that is distant from your ranch house, if you own a cabin in the mountains, or a remote summer or winter home beside a lake, this type of solar power system can often be the most cost effective method of providing power to your remote off-grid location. When compared to bring in the power lines the initial cost can be less. Some of the pros of this type of system are: The lack off reliance on the utility. Potential cost savings. Some of the cons of this type of system are: Even thought there maybe a cost savings over running utility line, there can be a high initial cost. You have to know your loads and have the system designed correctly since you don’t have utility power for backup.
Grid-Tie Solar Power Systems
This system is the newest addition to our site. The system utilizes an inverter that does not require batteries. During the day, the power generated is fed back into the utility. If you are producing more power then you are using your meter can even spin backwards. Due to the simplicity of the system, it has the lowest cost per watt. The downfall of this system is that when the utility grid fails the system will shut down.
Battery Backup System
Utility---Battery Charger---Batteries—Inverter---AC Loads
This is a system that does not involve solar power. This system utilizing an inverter that has a built in battery charger. It will charges batteries and hold them at 100% waiting for a power outage or a brownout. Your critical loads will never see the power outage. Computers, home health equipment, and lights will continue to operate when the utility grid fails. This is a system that is great for areas where power is lost for short periods of time. The limit on this system is the amount of battery capacity that you have. The larger the batteries the longer your run time will be.
Utility Tied Battery Backup System with Solar
This system operates on the same principal as the Battery Backup System. The difference is the addition of solar.The solar is used to charge your battery bank. When the batteries are full the excess power is fed back into the grid. In the event of an outage, your critical loads are powered by the system, and the solar panels continue to charge the batteries. The benefit of this system is that you have the ability to sell power back and have the piece of mind that you critical loads will continue to operate. The drawback is the cost per watt is higher then a Utility Tied System.