In search of a sharper line focus: Rotating the ′etendue

Summary: Line-focus solar concentrators have been limited by the 2D concentration limit, but we propose a new design principle that bypasses this limit and achieves higher concentration ratios. By combining the concepts of etendue squeezing and tracking integration, we demonstrate a design example and provide efficiency values under different design conditions. This design principle opens up the design space for high-concentration line-focus solar concentrators and allows for a reconsideration of the trade-off between concentration and acceptance angle.

Summary: Line-focus solar concentrators are limited by the two-dimensional solar concentration limit, but it is possible to design concentrators beyond this limit using etendue squeezing, achieving higher concentration ratios and acceptance angles. By utilizing this concept, concentrators have been developed with simulated 75x and 218x concentration ratios, offering new possibilities for concentrated solar power systems.