What are the different types of PV inverters?

There are three primary tiers of PV inverters: microinverters, string inverters, and central inverters. Since microinverters are not rated for utility-scale voltages, we will largely ignore them in this article. String inverters convert DC power from “strings” of PV modules to AC and are designed to be modular and scalable.

What is a modular string inverter?

Flexible system design: Modular string inverters open many doors for system layouts. Inverters can be distributed at the end of array rows, clustered in “virtual central” arrangements, co-located near the point of interconnection, and anything in between. Increased energy harvest: String inverters with multiple MPPTs will produce more power.

Why did PV inverters become module-level microinverters?

Ironically enough, the drawbacks of early central inverters (mismatch losses, inflexible system design) led to the development of module-level microinverters. The PV inverter market of this era had two bookends: microinverters for residential and small commercial projects and increasingly large central inverters for everything else.

What is a microinverter & a string inverter?

Microinverters and other module-level power electronics can be found on residential rooftops as well as commercial systems. Central inverters are installed in large commercial and utility-scale systems. String inverters are designed for all system sizes. Central inverters are large — in the 1-5 MW range per unit.

Are central inverters better than string inverter?

Fewer equipment areas: Developers will inherently need fewer central inverters than string inverters for the same overall project capacity, leaving more space for the PV array and less for inverters and balance of system components. Lower perceived risk: Central inverters are more mature than string inverters.

How many kilowatts can a string inverter run?

Currently, developers can source string inverters rated for upwards of 350kW per unit. Many string inverter manufacturers offer skidded or cluster-mounted solutions that co-locate hundreds of kilowatts of string inverters into a “virtual central inverter” configuration. Some utility-scale developers are switching to string inverters due to: