The rapid expansion of solar photovoltaic capacity in Abu Dhabi presents a growing challenge of daytime energy surplus and grid curtailment. This paper proposes a circular solar-hydrogen energy optimization framework that transforms curtailed solar electricity (conventionally treated as waste) into a recoverable resource through green hydrogen production, storage, and nighttime re-electrification. The system integrates three distributed solar generation sources unique to the Abu Dhabi urban and coastal context: (i) building-integrated photovoltaic thin-film sheets applied to building envelopes and rooftops; (ii) offshore floating solar arrays positioned along the Abu Dhabi coastal shelf; and (iii) solar canopy domes installed over highway flyovers and bridge decks. Daytime surplus electricity is directed to polymer electrolyte membrane electrolysers for producing green hydrogen, which is stored and subsequently converted back to electricity via fuel cells during the evening and nighttime demand window, completing a 12-hour circular storage rotation. The dispatch strategy is formulated as a mixed-integer linear programming model that allocates generation across three operating modes (direct grid supply, hydrogen production, and hydrogen-to-power reconversion) while minimising curtailment and maximising net energy value delivered to the Abu Dhabi transmission grid. The circular economy principle is operationalised through a quantified waste-recovery key performance indicator, measuring the percentage of otherwise-curtailed solar energy recaptured through the hydrogen loop. Simulation results based on Abu Dhabi irradiance profiles and grid demand data demonstrate the technical feasibility of the proposed framework and quantify the round-trip efficiency, daily hydrogen throughput, and carbon displacement potential. The proposed model provides a replicable optimisation template for solar-surplus economies, and lays the groundwork for a full technoeconomic evaluation and UAE-wide deployment study as future research directions.