A solar inverter is the component of the solar system which is used to convert the DC power produced by the solar panels to the AC power which is used by our home electrical system and appliances. It may be a micro inverter, power optimizer or a string inverter. Microinverters and power optimizers are installed below the solar panels whereas a string inverter may be installed indoor or outdoor as per the installer recommendation or homeowner requirements.
Power optimizers are coupled with string inverters and optimize the power at the point of the solar panel. An optimizer is a perfect balance between string and microtechnology.
As power output from each of the solar panels is different, there are two ways of connecting them to the inverter. One way is the string method in which the panels are connected in strings with or without a power optimizer under panels and then connecting these strings to a central string inverter. A string inverter without power optimizers can be the most cost effective but also can be the least efficient especially in shaded areas. Its inefficiency comes from the fact that the panels are run together in a string (like Christmas lights). Because in this connectivity, if a single panel malfunction, then the complete string containing that panel will suffer and will go offline making the power output for that group of panels zero.
A more efficient way of connecting solar panels is to connect by micro inverters or power optimizers. These inverters or optimizers are installed below each of the individual solar panels and directly converts from DC to AC or in the case of the optimizer, it leaves the power at DC but optimizes and individualizes the voltage. The microinverters and optimizers are installed one for each panel or a maximum of one per two panels and are connected beneath the solar panels. They increase the overall efficiency of the system but are also adding extra cost to your budget, although the cost is recovered by the increase in efficiency of the overall solar system.
Usually, the string inverter is best to be installed near the inverter and electric equipment. It can be installed inside or outside the building at a convenient place for the homeowner such as the garage or basement. A general rule of thumb is to find a place from where you can easily connect to existing grid electrical apparatus.
The best place for the installation of a solar inverter is a place away from direct sunlight with proper air ventilation. The place should be easily accessible for maintenance purposes, preferably moisture resistant and facing north. Whether the proposed place for the inverter is indoor or outdoor, it should have a minimum clearance of at least half a foot on either side and above for air circulation. It is a best practice to keep a reasonable ground clearance of around 3 feet for any flood or rising water level incident.
For people planning solar for (New Jersey) homes, you may consider the following points while choosing a suitable place for inverter installation.
- An easily accessible place for routine checkup and maintenance
- Has at least 6 inches free space on all sides and top
- There should be no moisture source
- No direct sunlight on the apparatus
- Good ventilation
- Better if given a water level clearance of 3 feet for any flooding incident especially in a basement
- Safety from harsh weather conditions (for an outdoor unit)