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The escalating demand of global decarbonization has positioned green hydrogen as a governing clean energy carrier, yet its large scale viability hinges critically on the techno-economic performance of the production pathway chosen. This thesis presents a comprehensive optimization and economic assessment of a concentrated solar power (CSP) tower plant integrated with the sulfur-iodine (S-I) thermochemical cycle for green hydrogen production, with the central objective of minimizing the levelized cost of heat (LCOH) delivered to the hydrogen generation process. The CSP system was modeled using NRELs System Advisor Model (SAM) as a molten-salt power tower with a heat transfer fluid operating between 520°C and 800°C which is thermodynamically compatible with the high temperature H₂SO₄ decomposition stage of the S-I cycle. At a solar multiple of 2.7, a receiver thermal capacity of 945 MWt, and 10 hours of thermal energy storage, the plant delivers 2,033 GWht annually at a capacity factor of 66.3%, yielding an LCOH of 3.69 ¢/kWht at a total installed cost of $ 560.5 million. The hydrogen production economics were evaluated using the IAEA Hydrogen Economic Evaluation Program (HEEP), where in the S-I plant consumes 350 MWth and 10.5 MWe to produce 2.84 × 10⁷ kg H₂/year at a capital cost of 200$ million under a 4.25% discount rate, 30/70 equity to debt structure, and a 25-year operational horizon. The baseline levelized cost of hydrogen (LCOH₂) converges at 5.05$/kg H₂ at a plant efficiency of 33.18%, with operation and maintenance expenditures constituting 88.7% of total costs, a structural pattern consistent with nuclear high temperature steam electrolysis findings in the literature. A systematic one way sensitivity analysis across eight technical, capital, and financial parameters reveals that the thermal heat requirement for hydrogen generation is by far the dominant cost driver, exerting a ±15.78% influence on LCOH₂ a range 4.6 times greater than that of any other parameter examined. Critically, a 20% reduction in thermal heat demand would yield savings of 0.80 $/kg H₂, outweighing the full impact of equivalent capital cost reductions. Financial and electricity related parameters individually contribute less than ±1% variation, underscoring the thermal-dominant nature of thermochemical hydrogen production and its inherent insulation from electricity price volatility relative to electrolysis based pathways.