Wind turbine design optimization for hydrogen production
06 HYB24-90
Presented by: Christopher Bay
As pressure builds to limit climate change through decarbonization, hydrogen is of particular interest for decarbonizing areas that are carbon heavy, such as personal transportation, freight logistics, and industrial processes. Different types of hydrogen production methods have been classified based on their relative carbon footprints: grey/brown hydrogen are made using natural gas/coal respectively and have the largest carbon footprint; blue hydrogen is produced from fossil fuels, but emissions are offset with carbon capture and storage technologies; green hydrogen is produced using zero-carbon electricity sources such as wind and solar power.
Green hydrogen thus is the most attractive option in terms of environmental impact but currently has relatively high cost. This project looks to decrease this cost by designing turbines specifically for hydrogen production. Turbines are traditionally designed to minimize Levelized Cost of Electricity (LCOE). The power produced from these turbines is variable, as the wind is an intermittent resource, but also because wind turbines have been optimized for maximum total, long-term energy production with no considerations to minimizing short-term variability. However, hydrogen electrolyzer utilization rates suffer when provided intermittent power sources. Thus, connecting traditionally designed turbines to electrolyzer systems to make hydrogen is not optimal.
With this in mind, the authors have devised the necessary modeling and optimization framework to perform wind turbine design for hydrogen production. This framework includes a new open-source electrolyzer simulator to model hydrogen production, degradation, and Levelized Cost of Hydrogen (LCOH) based on experimental data and industry input, which is coupled with an open-source wind turbine design tool, WISDEM. As an initial case study, the team chose an onshore location near the Gulf of Mexico region based on customer feedback and interest in potential wind-hydrogen systems. A baseline turbine, the IEA 3.4MW reference turbine (rotor diameter of 130m), was used as a starting point. The optimizations were completed in sequential steps, starting with optimizing the tower and blades by adjusting the blade chord, twist, spar cap, tower height, and tower section thickness. The next step optimized the drivetrain for the redesigned rotor, adjusting numerous geometrical parameters. These optimizations were run for two different objectives: 1) minimize LCOE, and 2) minimize LCOH.
When minimizing LCOE for this location, the solver found an optimal rotor diameter of 150m, 20m larger than the baseline. This larger rotor allowed for more energy capture in the lower wind speeds of the gulf coast region, resulting in a decrease of 12.35% in LCOE compared to the baseline turbine. For minimizing LCOH, the optimizer pushed the rotor diameter even larger to 170m, 40m larger than the baseline, effectively lowering the rated wind speed of the turbine and producing a more consistent energy output over the year. This increase in consistency resulted in an increase in hydrogen production, as hypothesized, giving a reduction of 12.7% in LCOH compared to the baseline turbine, and an additional 1.53% reduction in LCOH from the LCOE-optimized turbine.
These results indicate that additional reductions in LCOH can be achieved by designing turbines for different objectives than are traditionally used, encouraging further investigation into co-design of hybrid power plants.
Green hydrogen thus is the most attractive option in terms of environmental impact but currently has relatively high cost. This project looks to decrease this cost by designing turbines specifically for hydrogen production. Turbines are traditionally designed to minimize Levelized Cost of Electricity (LCOE). The power produced from these turbines is variable, as the wind is an intermittent resource, but also because wind turbines have been optimized for maximum total, long-term energy production with no considerations to minimizing short-term variability. However, hydrogen electrolyzer utilization rates suffer when provided intermittent power sources. Thus, connecting traditionally designed turbines to electrolyzer systems to make hydrogen is not optimal.
With this in mind, the authors have devised the necessary modeling and optimization framework to perform wind turbine design for hydrogen production. This framework includes a new open-source electrolyzer simulator to model hydrogen production, degradation, and Levelized Cost of Hydrogen (LCOH) based on experimental data and industry input, which is coupled with an open-source wind turbine design tool, WISDEM. As an initial case study, the team chose an onshore location near the Gulf of Mexico region based on customer feedback and interest in potential wind-hydrogen systems. A baseline turbine, the IEA 3.4MW reference turbine (rotor diameter of 130m), was used as a starting point. The optimizations were completed in sequential steps, starting with optimizing the tower and blades by adjusting the blade chord, twist, spar cap, tower height, and tower section thickness. The next step optimized the drivetrain for the redesigned rotor, adjusting numerous geometrical parameters. These optimizations were run for two different objectives: 1) minimize LCOE, and 2) minimize LCOH.
When minimizing LCOE for this location, the solver found an optimal rotor diameter of 150m, 20m larger than the baseline. This larger rotor allowed for more energy capture in the lower wind speeds of the gulf coast region, resulting in a decrease of 12.35% in LCOE compared to the baseline turbine. For minimizing LCOH, the optimizer pushed the rotor diameter even larger to 170m, 40m larger than the baseline, effectively lowering the rated wind speed of the turbine and producing a more consistent energy output over the year. This increase in consistency resulted in an increase in hydrogen production, as hypothesized, giving a reduction of 12.7% in LCOH compared to the baseline turbine, and an additional 1.53% reduction in LCOH from the LCOE-optimized turbine.
These results indicate that additional reductions in LCOH can be achieved by designing turbines for different objectives than are traditionally used, encouraging further investigation into co-design of hybrid power plants.