In a recent webinar Christopher Barrett, technical services manager at APsystems, answered listener questions about using his company’s microinverters in commercial solar projects. These are some of the questions addressed – you can watch the full webinar here.
SPW: If using an APsystems microinverter in a commercial project, how do you decide whether to use the YC500 (which attaches to two modules) or the YC1000 (which attaches to four modules)?
Barrett: Typically the YC500 single-phase inverter is used for residential systems. It can be used in a commercial environment but only in 120Y, 208V systems, since that’s the voltage in which the single-phase inverter is able to operate. It has to be balanced by the installer. For a true 3-phase system, the YC1000 is the clear winner because of its five-wire system, and the fact that it’s phase balanced and phase monitored.
SPW: Does your 3-phase microinverter, the YC1000 require neutral and ground wiring? Will it work where neutral is not available or an existing ground?
Barrett: Yes, our YC1000 is required to have neutral and ground wiring. Our microinverter works in a “Y” configuration, not a Delta configuration, so a 3-phase Y is important – 120Y-208 volt systems and 277Y/480 volt systems.
SPW: Will APsystems microinverters work with any solar module?
Barrett: APsystems microinverters will work with any module out there.
SPW: Reliability is very important thing, but so is cost. What would you say to those installers who argue that a microinverter is expensive?
Barrett: It really depends on the application—what you’re doing and what you’re looking to get out of the project. You may pay more up front for microinverters, but you’re likely to save when it comes to the overall cost of the project and the levelized cost of energy. Microinverters have the option to extend to a 25-year warranty versus a 10-year warranty with string inverters. You’re also getting module-level monitoring and greater energy harvest. And you’re not spending extra money to meet NEC requirements for rapid shutdown arc fault detection. It really comes down to what you value in the long term.