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Grid-connected large-scale hydrogen production by water electrolysis

University of British Columbia

Hydrogen can play a vital role in a net-zero-emission future because it can be used as fuel in many applications as well as a large scale energy-storage medium. The generation of hydrogen by water electrolysis powered by renewable energy is among the solutions to provide low-carbon hydrogen. Even though the technical feasibility of water electrolysis is demonstrated, the economic analysis and energy system integration on a large scale is not fully covered yet. In this thesis, a techno-economic analysis was performed for large-scale hydrogen production plants (4,000–40,000 kgH₂/day or approximately 10–100 MW). Two electricity pricing schemes in 8 different geographical locations were considered including five Canadian provinces with flat rates and real-time pricing for the wholesale markets in Germany, California, and Ontario. The flat-rate pricing yielded a range for the levelized cost of hydrogen produced via water electrolysis (e.g., $4.21–$4.71/kgH₂ in Québec). For the wholesale electricity markets, an operational strategy was developed that aims to identify if a posted price is high or low based on historical electricity spot prices. The electricity cost can be reduced by 4%–9% in Germany and by 15%–31% in Ontario and California at a capacity factor of 0.9 by implementing this operational strategy. Electrolytic hydrogen production in Ontario combined with underground storage was found to be the cheapest in the three wholesale electricity markets, resulting in a levelized cost of hydrogen of $2.93–$3.22/kgH₂ for alkaline electrolysis and $2.66–$3.54/kgH₂ for proton exchange membrane electrolysis. Compared to steam methane reforming at $2.5–$2.8/kgH₂ (without carbon capture), the electrolytic hydrogen cost is 6%–27% higher. However, this cost becomes comparable to that from steam methane reforming once carbon capture and storage are included in the analysis. Our results suggest that maximizing the use of the electrolytic systems via high capacity factors is economically favorable, especially under integration with wholesale electricity markets.

Text

2019-11-06

Attribution-NonCommercial-NoDerivatives 4.0 International

http://hdl.handle.net/2429/72210

Mechanical Engineering

University of British Columbia

UBCV

http://creativecommons.org/licenses/by-nc-nd/4.0/