Solar power provided more than 1,600 TWh of power in 2023, accounting for more than 5% of global electricity generation. In fact, solar power installations are rapidly becoming the most popular and ubiquitous renewable energy sources, due in large part to their modular, relatively unobtrusive nature. Installations can be small, with just a few panels installed on a home rooftop, or can be expanded into medium-sized installations mounted on commercial buildings and even gigawatt-scale solar farms. 

The potential impact of a solar installation on a community is far lower than a hydroelectric dam, which may require rerouting of waterways and dramatic changes to private, public, and recreational resources hundreds of miles downstream; and is significantly less intrusive than today's massive wind turbines, which can be seen from as much as 20 miles away. 

This modular nature of solar panel installations can be problematic, however; installations may feature tens or thousands of panels which are typically connected in series and parallel at a junction box. These connections tie the performance of panels together, with a weak-performing panel dragging down the performance of the others in an array. Whether this is due to a faulty panel that must be replaced or smaller, natural variations in performance as panels ages over its ~30-year lifetime, the result is lower overall power input and underperformance by many panels in the array. Existing solutions to address this have typically incorporated expensive panel-level electronics such as microinverters, DC:DC converters or buck-boost converters, all of which introduce losses that reduce overall system efficiency.

Researchers have developed a technology that optimizes individual photovoltaic solar panel performance while maintaining the high system-level efficiency of conventional arrays with centralized inverters. This is achieved via differential power processing: each panel is controlled to operate at its maximum power point, with nearly all current routed directly toward an efficient centralized inverter. Smaller current differences among panels are routed through small DC-DC converters to support panel-by-panel optimization. 

This approach allows the output of higher-performing panels in an array to be harvested fully without having to subject total panel power to two conversion process steps, as with typical “dc optimizer” schemes. The result is an optimally performing array that benefits from both the flexibility of panel-level optimization and the high efficiency of centralized inverters. 

Publication

https://ieeexplore.ieee.org/abstract/document/6256743