Techno-Economic Assessment of Ammonia-Fueled Combined Cycle Gas Turbines for Power Generation in Saudi Arabia

Abstract Ammonia is rapidly emerging as a leading candidate among synthetic fuels for low-carbon power generation, offering carbon-free combustion and favorable energy density. It can be produced from renewable sources such as solar and wind through green hydrogen pathways and is easier to store and transport than hydrogen itself. With increasing global interest in decarbonizing baseload electricity systems, ammonia presents a scalable, energy-dense, and technically viable fuel alternative to natural gas. This study assesses its feasibility in combined cycle gas turbine (CCGT) applications tailored for conditions in the Kingdom of Saudi Arabia. A comprehensive techno-economic assessment was conducted using Aspen HYSYS to simulate a 2×2×1 H-class CCGT system retrofitted to combust ammonia. The model captured combustion dynamics, turbine performance, steam cycle integration, and heat rate variations due to ambient temperature effects. Economic inputscapital expenditure (CAPEX), operational expenditure (OPEX), and fuel delivery costs—were derived from NETL, PJM, and EIA data and escalated to 2022 USD using CEPCI multipliers. Scenarios were evaluated for both greenfield installations and brownfield retrofits of natural gas systems. The financial evaluation used a discounted cash flow (DCF) model to compute levelized cost of electricity (LCOE). Results indicate that while ammonia incurs higher fuel and NOx abatement costs than natural gas, its LCOE can approach competitiveness under specific conditions—particularly in retrofit cases and with supportive carbon pricing. Ammonia-fired CCGT systems exhibit resilience under high-temperature ambient conditions typical of Saudi Arabia, with only marginal heat rate penalties. The study concludes that ammonia, when supported by infrastructure investment and carbon policy frameworks, can be a cornerstone fuel in transitioning to a low-carbon utility power sector.