Solar inverters convert DC to AC and make it possible to harness solar energy. The power produced by solar photovoltaic (PV) modules is in direct current (DC) watts, but the power utilized by electrical equipment is in alternating current (AC) watts.There are three different types of solar inverters: string inverters, micro-inverters, or optimizers.
A string inverter is the most commonly used inverter around the world and the best option when there are minimal chances of shading and all of the modules face in one direction. In a rooftop PV system, usually a few modules of the same output voltage and power are connected in series together in a “string.” Several such strings are connected in parallel at the solar inverter input. The string inverter needs to accommodate these inputs at predefined voltage and power levels, which means the string inverter needs to be sized appropriately. A PV to inverter power ratio of 1.15 to 1.25 is considered optimal, while 1.2 is taken as the industry standard. This means it is always better to choose a solar inverter with an input DC watts rating 1.2 times the output of the PV arrays.
The only problem with string inverters is that since the string consists of series-connected solar modules, malfunction of one would result in an overall drop of voltage. Even a minor problem of shading across one panel would bring about the same effect to the rest of the panels.
Micro-inverters are the solution to this problem. Though they are more expensive, investing in micro-inverters will ensure maximum possible production of the PV array at all times. This is because each module has its own micro inverter, therefore voltage or current loss on one panel doesn’t limit the power potential of other panels.
Optimizers are add-ons to a string inverter, but are situated at each module. It alters the DC output of the module in a way to attain maximum efficiency and is then sent to a string inverter. It also protects against arrays with shading and where the modules face different directions.
So, when it comes to choosing a solar inverter, every situation is different and we are here to help you determine which is best for you and your energy needs.