Project Name: Compact and Low-Cost Microinverter for Residential Systems
Funding Opportunity: Advanced Power Electronics Designs for Solar Applications
SETO Subprogram: Systems Integration
Location: College Park, MD
SETO Award Amount: $1.9 million
Awardee Cost Share: $500,000

This project team will design a manufacturable, holistic microinverter using gallium nitride (GaN) semiconductors and a new circuit containing fewer components and filters than conventional devices. The microinverter will be designed to operate continuously for more than 250,000 hours—the equivalent of about 28.5 years—on residential rooftops and in commercial installations while achieving higher efficiency and lower costs.

APPROACH

The team will design a low-cost GaN microinverter and investigate a hybrid of low-cost silicon and wide-bandgap GaN semiconductors. The bandgap is a measure of energy that signifies the distance between an electron’s starting point and the point it has to move to in order to conduct electricity. The team will create a control strategy that enables soft switching in the semiconductors, which reduces stress inside the device by filtering high-frequency current oscillations, and design a small, efficient transformer to enable mass production. To assess how heat affects the microinverter’s reliability, the team will conduct failure-mode analyses and design an air-cooled prototype, then test and verify the prototype to ensure it meets target metrics for cost, efficiency, power density, and reliability.

INNOVATION

The microinverter design will use state-of-the-art wide-bandgap GaN semiconductors and implement advanced control and thermal management techniques. The design also eliminates electrolytic capacitors, which will reduce the ways the device can fail, increase its efficiency, and lower system costs. By significantly reducing the cost of photovoltaic microinverters, increasing their reliability, and boosting power density, this project will help accelerate the adoption of solar energy for residential and commercial systems.