What are the different types of inverters?

There are four main types of inverter systems available for your system depending on the size of the array and application.

Microinverters. Microinverters are small inverters that are mounted to the back of each solar panel. The advantages of this type of system are better management of shading losses and individual solar panel monitoring. There is a premium on this technology so the shading losses need to be quantified and weighed against the additional cost. In addition to higher costs, microinverters also introduce more points of potential failure into the system. Make sure you understand the warranty policy of the manufacturer and installer prior to investing in this technology.

String Inverters. String inverters manage many solar panels that are grouped together in strings. Strings are solar panels that are electrically connected together in series. String inverters are economical and reliable but may not produce as much energy in the instance of severe shading. A shading study should always be performed by the installing contractor to verify how a string inverter will perform and weigh this against the value of the lost energy. String inverters are the preferred technology at Axium Solar based on cost, performance and reliability.

DC Optimizers and String Inverters. In the instance of shading, a hybrid DC optimizer and String inverter solution is another option. DC optimizers are small devices that manage 1 or 2 solar panels at a time and help them produce the most energy they can without impacting neighbor solar panels in the string. Without optimizers, the voltage on the entire string is compromised when one panel in the string is shaded. Optimizers limit the shading loss to only the impacted panels. Another advantage is the panel level monitoring, similar to the microinverter system. Like the microinverter system, the value of the lost energy due to shading needs to be weighed against the additional cost and multiple failure points.

Central inverters. When systems grow to around 5MW or above, then it is time to consider a central inverter. Central inverters are large, high capacity inverters that are at least 1MW AC or more and are often coupled with a step-up transformer to boost the output AC voltage so the energy can be transported longer distances. As such, these inverters are typically deployed in large, utility scale ground mounted systems.