Oyster mushroom cultivation under agrivoltaic systems in Malaysia improved returns compared with standalone solar and conventional mushroom farming. The model found AVS increased mushroom-farm AROI by 42%, IRR by 42%, and shortened payback by 13 months, while also improving PV returns slightly. Using on-site solar power could cut mushroom-farming emissions by 2.376–2.467 tCO₂ per year, turning shaded solar land into food, energy, and climate value.