Besides absorbing light, many carotenoids protect the plant by:

1. A leaf in full sun receives more energy than its reaction centres can use. 2. Surplus excitation would otherwise damage the photosystems. 3. Many carotenoids reside in the thylakoid membrane, absorb excess energy, and safely dissipate that energy as heat. 4. That protective role is separate from their contribution to light harvesting. _Source: OpenStax Biology for AP(R) Courses (CC BY 4.0), Ch 8 'Photosynthesis', sections 8.1-8.3_