Green energy conversion and storage materials have become a focal point of research in recent times, especially in energy-consuming buildings. Phase change materials (PCMs) have gained more and more attention not only for energy storage but also in composites for solar energy conversion. This research investigates a sustainable method for converting orange biomass waste (OBW) into advanced porous carbon aerogel (PCA) composites, designed for solar-thermal energy harvesting and storage in building applications. Using potato starch as a binder, the research develops a process for producing a uniform and lightweight carbon matrix that could be scalable. The best results were found for PCA obtained with 2.5% starch, where the lowest mass loss (8.2, 0.5, 11.2% pt) was observed during the leakage test. This study highlights the suitability of OBW-derived aerogels as effective matrices for PCM impregnation and shape stabilization, indicating their future potential in solar-thermal energy conversion and storage and potentially lowering energy consumption in buildings. By repurposing agricultural waste, this work contributes to sustainable material development and advances the application of renewable energy technologies.