Co-located wind and hydrogen energy systems

Journal of Mechanical Design (2024, featured article), first author; TORQUE 2022, first author

Hydrogen systems
How do electrolyzers, hydrogen storage and fuel cells change the cost, curtailment and firm output of a grid-connected wind farm?

First author

  • 253-MW wind farm, Texas
  • 8,760 hours
  • Four system configurations
  • MILP (REopt extension)
  • Four ISO wind profiles

Research question

How do electrolyzers, hydrogen storage and fuel cells change the cost, curtailment and firm output of a grid-connected wind farm?

Key insight

A higher hydrogen price raised hydrogen's levelized cost but lowered system cost

As the hydrogen price rose, the optimizer built a larger electrolyzer to use more surplus wind. The larger unit ran at lower utilization, so each kilogram carried more capital and the levelized cost of hydrogen rose, while hydrogen revenue lowered total system cost. The cost per kilogram and the system's cost moved in opposite directions.

Why can a costlier kilogram mean a cheaper system?

A higher hydrogen price makes each kilogram worth more, so the optimizer builds a larger electrolyzer to capture more surplus wind. The extra capacity runs fewer full-load hours, so the cost per kilogram, the levelized cost of hydrogen, goes up. Yet the added hydrogen revenue lowers the net cost of the whole system. The cost per kilogram and the system's cost move in opposite directions.

Illustrative model with stylized numbers: it shows the mechanism described in the paper, not the study's data or results.

My contribution

First author. I did most of the work: I extended NREL's REopt optimization model with hydrogen components, ran the analysis and did the writing.

How I approached it

  1. ChallengeNREL's REopt optimization model had no electrolyzer, hydrogen tank or fuel cell.

    What I didI extended REopt with these three components, with their costs, efficiencies, hydrogen sales and constraints, so it sizes and dispatches wind, battery and hydrogen equipment together.

    Why it matteredFour system configurations could then be compared in one mixed-integer model.

  2. ChallengeA wind farm's value to the grid depends on firm output, not only on the energy it sells.

    What I didI set the model to deliver the largest stabilized output in every hour at the lowest life-cycle cost, and compared battery, hydrogen and hybrid storage on that basis.

    Why it matteredHybrid hydrogen and battery storage delivered the highest stabilized output of the four configurations.

  3. ChallengeResults from one site and one weather year may not hold elsewhere, or as equipment costs fall.

    What I didI repeated the analysis with wind profiles from four ISO regions and with projected component costs to 2050.

    Why it matteredThe ERCOT site had the lowest costs but the highest curtailment, and falling costs led to larger electrolyzers and less curtailment.

Design choices

Fix the wind farm at its planned 253 MW
Alternatives considered: optimizing wind capacity together with storageThe study asks how storage and hydrogen should be added to a planned farm near Snyder, Texas, so only those components are sized.

Method

Mixed-integer sizing and dispatch optimization for a 253-MW West Texas wind farm with ERCOT prices, with sensitivities to hydrogen price, region and future technology costs.

Key findings

  1. In the Journal of Mechanical Design case study, adding an electrolyzer reduced total system cost by about 7%.
  2. In the same study, using hydrogen storage with fuel cells reduced it by about 26% and sharply cut curtailment (the earlier TORQUE 2022 case reported about 9% and 30%).

Boundary conditions

Cost assumptions date from 2020–2023 and predate final federal hydrogen credit rules.

What it led to

I reused the extended model and added a concentrated-solar module to compare solar-hydrogen designs. Co-located solar and hydrogen plants

Publications

  1. J. Mech. Des.
    Towards sustainable integration: techno-economic analysis and future perspectives of Co-located wind and hydrogen energy systems
    H. Li, J. Zhang
    Journal of Mechanical Design, vol. 146, article 020903, 2024. Featured Article
    DOI Accepted manuscript (PDF) Code Cited by 28
  2. TORQUE 2022
    Optimal planning of co-located wind energy and hydrogen plants: a techno-economic analysis
    H. Li, J. Rahman, J. Zhang
    Journal of Physics: Conference Series, vol. 2265, article 042063, 2022.
    DOI PDF Code Cited by 17

Citation counts: Google Scholar, October 30, 2026.

  • Integrating offshore wind farms with unmanned hydrogen and battery ships — IEEE KPEC 2022 (third author).