SiC and GaN technologies will become the key to cost competitiveness in photovoltaic inverters

According to a report by Lux Research, driven by downstream demand for solar modules, wide bandgap semiconductors, namely silicon carbide (SiC) and gallium nitride (GaN), will lead the solar inverter isolator market to $1.4 billion in 2020, which means a stable compound growth rate (CAGR) of 7%, slightly lower than the 9% compound growth rate of renewable energy and grid-based energy equipment. As GaN and SiC devices enter the market, they will bring the greatest competitive advantage to small systems, such as microinverters and small string inverters for residential and commercial solar facilities. These powerful advantages include: lower average power costs, increased profits from electricity sold through leasing and power purchase agreements, and these devices can also improve performance and reliability.

“采用宽禁带半导体即碳化硅和氮化镓，是太阳能逆变器的制胜之道，”Lux Research分析师Pallavi Madakasira表示，“采用SiC和GaN器件带来的性能优势是如此之多，以至于逆变器厂商能够在显著降低均化电力成本的同时，收取更高的价格。”

GaN and SiC device advantages

To understand the performance benefits of GaN and SiC devices, Lux Research analysts modeled three main inverters using Si, SiC and GaN components – microinverters, string inverters and central inverters. The results are as follows:

Smaller inverters for higher efficiency

Power electronics with GaN and SiC isolators can increase the efficiency of solar microinverters and string inverters to more than 98%, which is beyond the reach of currently used silicon devices. Diodes can increase energy collection efficiency by more than 1.5%, while transistors can increase it to more than 4%. GaN-on-silicon provides the lowest cost solution, while GaN-on-SiC and SiC-on-SiC provide higher efficiencies.

Microinverters will command the highest premium

SiC and GaN have the largest price premium capability in the microinverter space (>$0.10/Wp) without increasing the cost of electricity. Although still a niche solution, the microinverter space remains attractive and is expected to be an early introduction of SiC and GaN solutions and show shipment growth.