Building integration of Silicon-photovoltaic (Si-PV) panels into urban infrastructure faces efficiency and aesthetic concerns. An effective alternative is the luminescent solar concentrators (LSCs), in which the emitters embedded in polymer blocks capture, converts, and guide the sun irradiation to the edges where Si-PV panels are placed. The best LSCs are based on rare-earth and/or toxic emitters, which undermines the sustainability of this technology. In this context, a few groups have implemented biogenic emitters like fluorescent proteins (FPs) and protein systems in liquid-state LSCs, reaching the maximum optical efficiency (ηopt) of 6.88%. However, liquid-state LSCs face low photostability and easy leakage issues. Herein, it is demonstrated that the concept of FP solid-state LSCs, integrating an archetypal FP (T-Sapphire) in light-guiding epoxy materials of arbitrary shapes. They are optimized with respect to the water content and the type/amount of stabilizers, fairly keeping the photoluminescence features over 250 days under storage conditions. This allows the fabrication of FP solid-state LSCs that achieve a 32-fold enhanced stability compared to liquid-state LSCs (8 days vs 6 h) and the best ηopt of 7.41%. Overall, this work provides a key advancement toward truly sustainable LSCs, marking a major step toward biologized photovoltaics.