Review Reports

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Green hydrogen is significant for the decarbonising agriculture. However, there are several key problems needed to be addressed in this manuscript.

1. In the 3rd paragraph of introduction, the authors think agricultural sector accounts for 71% of nitrous oxide and 49% of methane emissions. So the decarbonization should focus on the emission reduction of nitrous oxide and methane. However, the green H2 is used to decrease the consume of fossil fuels in the agricultural sector. This is confused for the readers.
2. The manuscript should clarify the industrial maturity grade of hydrogen-powered tractors, diggers, and forklifts.
3. The last paragraph of introduction need to be completely rewritten, instead of just like a catalogue.
4. The word in the figure is blurry, please revise.
5. The H2 demand in Figure 3 is strange, as it maintains between month of 3 to 8.
6. The manuscript contains many grammatical and format errors: Line 38, 418, 466, 513, 881, 891…
7. The Abstract lack of innovative viewpoint.
8. The manuscript need more description of technology for green H2 production and consume, eg electrolyser, fertiliser synthesis, et al.

Author Response

We thank the reviewers for their valuable comments. This document entails how we addressed their concerns and subsequent revisions we made to the manuscript. 

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

This article envisions a scenario where renewable energy sources such as wind and solar power on farms are used to generate "green electricity", green electricity is used to electrolyze water to produce "green hydrogen", the generated hydrogen is used to replace fossil fuels to drive tractors and other agricultural machinery, and hydrogen is used to synthesize ammonia as fertilizer, achieving sustainable agricultural production that does not rely on fossil fuels. This idea has enormous potential value, especially given that the main fossil energy supply in the EU is currently in an insecure state: the sea transportation lines from Middle Eastern oil producing areas to Europe are under the control of superpowers' navies, which allows Europe's energy security to be manipulated by superpowers; The supply of Russian oil and natural gas to Europe has been disrupted by the war. In this situation, using green hydrogen to replace oil and natural gas to solve the supply of agricultural machinery fuel and fertilizer undoubtedly has attractive prospects.

However, the perspective of this article mainly focuses on the European region, while ignoring solutions in other places. Like the European Union, China also faces the security issue of external supply of oil and natural gas, and is committed to the utilization of new energy and hydrogen energy. At present, China is the country with the largest scale of new energy utilization. China's application scale in the fields of photovoltaic power generation, hydropower generation, and wind power generation is leading Europe, especially in the photovoltaic industry, which ranks first in the world. The Chinese have laid photovoltaic power generation facilities in vast deserts, erected wind turbines on the sea, and built large-scale water conservancy facilities in the Yangtze River and the Yarlung Zangbo River for hydropower generation. Such large-scale facilities may be more efficient than using farm wind and light to generate green electricity.
In addition, new energy vehicles in China, the United States, and Europe all use batteries as power instead of hydrogen engines, due to Japan's monopoly on patents for hydrogen internal combustion engines, which requires additional high costs to directly drive cars or agricultural machinery with hydrogen. Therefore, using hydrogen to drive tractors or other agricultural vehicles will encounter intellectual property monopoly issues. When considering feasibility, it is necessary to add intellectual property considerations.
In addition, the reaction of synthesizing ammonia using hydrogen and nitrogen is difficult to carry out on-site on farms. The current synthetic ammonia industry uses hydrogen to produce ammonia, requiring large-scale factories. On site production of ammonia gas is currently technically immature. The author needs to provide a new solution.
We suggest that: (1) when hydrogen is used as a power source for agricultural machinery, intellectual property issues need to be considered; (2) It is difficult to synthesize ammonia on the farm, and we hope the author can provide a new plan; (3) Is it necessary to supplement the possibility of producing green hydrogen in other areas (such as deserts and sea surfaces) besides farms?

Author Response

We thank the reviewers for their valuable comments. This document entails how we addressed their concerns and subsequent revisions we made to the manuscript. 

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

The paper offers a significant contribution to the discourse on agricultural decarbonisation by integrating techno-economic modelling with stakeholder engagement (semi-structured interviews and expert workshops). Its originality lies in exploring cooperative hydrogen hubs as a practical solution to overcome the economic and institutional barriers to on-farm hydrogen production. The paper’s key strengths include a well-designed mixed-methods approach, clear articulation of technical opportunities, and actionable policy recommendations that link theory to practice. It effectively bridges the technical, economic, and social dimensions of hydrogen adoption, offering a holistic perspective that is often missing in similar studies.

Nonetheless, several areas could be strengthened to improve the manuscript’s academic rigor and impact. Below are specific, section-linked recommendations.

1. Expand the literature review to include a broader range of recent studies on agricultural hydrogen adoption, particularly comparative international case studies and socio-technical transition theory.

2. More clearly construct research questions/hypotheses. Currently, the research aim is implied rather than explicitly stated, which weakens the framing of the study.

3. While the stakeholder-guided approach is valuable, the paper could more explicitly position itself against existing techno-economic modelling studies (e.g., those in Sweden, Germany, and Australia) to clarify its unique contribution beyond the UK context.

4. Although the paper engages with techno-economic and regulatory literature, it pays limited attention to behavioural adoption theory (e.g., Technology Acceptance Models) and innovation diffusion frameworks, which could strengthen the interpretation of farmer attitudes.

5. Provide more detail on sampling criteria for interview participants and justify the representativeness of seven interviews as sufficient for thematic saturation.

6. Offer more transparency in scenario construction for techno-economic modelling — e.g., assumptions behind diesel price forecasts, sensitivity analysis ranges, and uncertainty treatment.

7. Include a brief reflection on limitations of the mixed-methods approach (e.g., potential bias from workshop participants, generalisability of case study results).

8. The techno-economic results are reported clearly, but statistical treatment or formal uncertainty quantification would improve robustness.

9. Link the results more explicitly to the research questions and policy frameworks (e.g., UK Hydrogen Strategy) to strengthen the theoretical contribution.

10. Expand discussion of commercialisation pathways, financing models, and potential integration with carbon credit schemes.

11. Address global relevance, how might these findings translate to regions with different farm sizes, energy mixes, or policy environments?

12. Discuss potential societal trade-offs, such as land-use competition between food and energy production, in more detail.

13. The paper includes useful schematics (e.g., Figure 1, challenges diagrams), but several key results (e.g., LCOH sensitivity, cost trajectories to 2040) could be better communicated through graphs and comparative bar charts for improved clarity and reader engagement.

14. Consider including a visual summary of the three business models, comparing their costs, risks, and social acceptance levels.

Author Response

We thank the reviewers for their valuable comments. This document entails how we addressed their concerns and subsequent revisions we made to the manuscript. 

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

I suggest publication of this manuscript

Reviewer 3 Report

Comments and Suggestions for Authors

The revised manuscript shows clear improvement in several areas addressed during the previous round of review. The authors have strengthened the literature review by incorporating broader and more up-to-date sources, clarified their research framing, and provided more transparency in both the stakeholder sampling and the techno-economic modelling assumptions. The integration of behavioural adoption perspectives and expanded discussion of policy and international relevance further enhance the paper’s contribution. Overall, the revisions improve the manuscript’s academic rigor, clarity, and impact, and demonstrate responsiveness to reviewer feedback.