echno-economic and environmental evaluation of green hydrogen co-firing in a 570 MWe gas turbine combined cycle power plant in Iraq

The study evaluates the interconnections between renewable energy generation, hydrogen production, storage, and the operational demands of hydrogen co-fired gas turbine combined cycle (GTCC) power plants for carbon-neutral energy production. Specifically, it assesses the technical, economic, and environmental aspects of producing green hydrogen from hybrid photovoltaic (PV) and wind turbine (WT) sources in Dhi Qar, Iraq. The analysis considers three scenarios with varying hydrogen mole fractions (15 %, 30 %, and 50 %) co-fired with natural gas in a 570 MWe of the GTCC power plant, emitting 1.39 million tonnes of CO₂ annually. Baseline renewable electricity generation capacities for solar PV and wind energy were set at 497.5, 970, and 2200.5 MWp, with hybrid PV/WT systems optimized to supply power to an alkaline water electrolyzer (AWE) with capacities of 180, 425, and 825 MWp, based on hourly weather data from 2023. Multi-objective simulations and optimizations were performed using HOMER Pro and ProSim software to minimize the net present cost (NPC), levelized cost of energy (LCOE), cost of hydrogen (COH), and CO₂ emissions. Over the proposed 20-year project lifespan (2023–2043), green hydrogen production ranged from 12,082 to 54,442.9 tonnes annually, with a COH between $3.29 and $3.16 per kilogram, demonstrating the economic viability of large-scale hydrogen production. Hydrogen consumption in the GTCC fuel mixture ranged from 10,554.1 to 47,431 tonnes annually, reducing CO₂ emissions by 67,864.3 to 310,831.4 tonnes annually. Additionally, natural gas use decreased by 5.22 %–29.1 %, yielding savings of $6.79 to $31.08 million from avoided CO₂ emissions costs. However, despite the environmental and fuel cost benefits, the NPC for the green hydrogen project ranged from $412.9 million to $1.785 billion, and the LCOE for hydrogen co-combustion in the GTCC power plant ranged from $113.54 to $127.74 per MWh, compared to $107.93 per MWh for 100 % natural gas-based power generation.