Wide bandgap semiconductors—specifically, silicon carbide (SiC) and gallium nitride (GaN)—are expected to lead the charge as the market for solar inverter discrete devices, driven by the downstream demand for solar modules, grows to $1.4 billion in 2020, according to Lux Research. That increase reflects a solid 7% compound annual growth rate (CAGR), slightly lower than the 9% for all renewables and grid-based power electronics.

As devices featuring GaN and SiC hit the market, they’ll offer the biggest competitive advantage in small systems—microinverters and small string inverters for residential and commercial solar installations—with the proposition of lowering levelized cost of electricity (LCOE) and increasing margins on electricity sold through leases and power purchase agreements. In addition, they are expected to deliver improved performance and reliability.

“The holy grail for solar inverters is the implementation of wide bandgap semiconductors, specifically, silicon carbide and gallium nitride,” said Pallavi Madakasira, analyst at Lux Research. “The performance benefits from both are such that inverter suppliers could charge a premium price and still achieve a significantly lower LCOE.”

To understand the performance benefits of switching to GaN and SiC, the analysts modeled the three major types of inverters (microinverters, string inverters and central inverters) with Si, SiC, and GaN components. Their findings included:

• Higher efficiencies in smaller inverters. Power electronics with discrete devices made from GaN and SiC, rather than incumbent silicon, can increase efficiencies for solar micro- and string inverters to over 98%. The diodes increase harvested energy by more than 1.5% while the transistors can increase it by more than 4%. GaN-on-silicon reportedly offers the lowest cost solution, while GaN-on-SiC and SiC-on-SiC offer far superior efficiency.
• Microinverters will command the highest premiums. SiC and GaN have the greatest price premium power (more than $0.10/Wp) in microinverters, without increasing LCOE. Though a niche solution, the microinverter segment is also an attractive segment for SiC and GaN to see early adoption and ramp up volumes.
• Indirect benefits add to the value proposition. GaN and SiC also result in indirect cost savings in the form of a reduced failure rate of passive components, footprint reduction and savings in installation cost. Also, their superior thermal conductivity reduces the size of the heat sink in inverters.

For additional information, visit www.luxresearchinc.com.