Stationary solar concentrator delivering beyond the étendue law with homogeneous illumination

We describe a concept for a novel stationary solar concentrator that relies on a new self-adaptive optical valve, non-imaging optics and the integrating sphere principle. Our analytical model reveals that this unique combination theoretically allows reaching a concentration up to around 9.5 suns, which a factor of 4.5x higher than the limit imposed by the fundamental étendue law, and provides perfect illumination homogeneity. These features are ideal to boost the performance of photocatalytic/photochemical reactors.