Microinverters, AC modules, and optimizers include performance-sensing and communication to monitor each PV module. Communications may be through the power-line communications (PLC), Ethernet, or a wireless radio in each unit, similar to the Wi-Fi in laptop computers. The communications schemes are proprietary to each manufacturer. Optimizer manufacturers are collaborating with string inverter makers to provide compatible products that recognize each other’s communication methods, and can thus work together for even higher performance.
PLC-based monitors are generally reliable up to 150 feet from the microinverters. Distance is reduced by interference sources on the power line, such as light dimmers and electronic power supplies. Manufacturer-supplied power-line filters may help in such cases.
Wireless communications systems don’t suffer from interference sources on the power line, but can be affected by large metal objects and metal roofs. To counter this, manufacturers such as Enecsys offer “repeaters” for installation between the array and monitor to boost the signal. APS America’s repeaters allow the monitor to be located up to 1,500 feet from its microinverter installations.
Monitors offer power and cumulative energy stats about individual module/MLPE pairings in a system. Apps are sometimes available for monitoring via handheld devices like smartphones.