Publications

2026

1. SoftwareX

   Geo-X: Generalised Geospatial Software for Production of Green Commodities

   Miguel Sanchez-Lopez, Samiyha Naqvi, Alycia Leonard, and 2 more authors

   2026

   Abs DOI Bib

   Geo-X is an open-source geospatial optimisation tool designed to estimate the production costs of green commodities such as hydrogen and ammonia. Building on the GeoH2 model, Geo-X introduces a fully generalised structure that enables the integration of multiple renewable energy sources and diverse commodity production pathways. The software couples detailed techno-economic plant optimisation with spatially explicit assessments of transport and infrastructure, managed through a reproducible Snakemake workflow. Geo-X supports applications across data-rich and data-constrained contexts, providing transparent, extensible modelling for policymakers, researchers, and practitioners. Its capabilities are demonstrated for hydrogen and ammonia production in Ukraine and Ghana.

   @unpublished{sanchez_lopez_geox_2026,
     title = {Geo-X: Generalised Geospatial Software for Production of Green Commodities},
     author = {Sanchez-Lopez, Miguel and Naqvi, Samiyha and Leonard, Alycia and Schirren, Lukas and Hirmer, Stephanie},
     journal = {SoftwareX},
     year = {2026},
     doi = {10.1016/j.softx.2026.102712},
     url = {https://doi.org/10.1016/j.softx.2026.102712}
   }

2025

1. Preprint

   Hydropower-Enhanced Spatial Modelling for Green Hydrogen in Data-Constrained Countries

   Lukas Schirren, John Ward, Sounthisack Phommachanh, and 2 more authors

   2025

   SSRN Preprint

   Abs DOI Bib

   Hydropower is a major renewable electricity source in many regions, yet its integration into spatial planning tools for green hydrogen production remains limited. Existing models predominantly focus on wind and solar, and those that include hydropower often lack comprehensive, spatially explicit, least-cost optimisation, particularly for data-constrained, hydropower-rich regions. This study presents the first open-source, globally applicable geospatial model (GeoH2) that fully integrates hydropower alongside wind and solar for optimal green hydrogen site selection. The approach leverages open-access datasets and minimal site specific information, making it especially suitable for countries with limited data availability. The enhanced GeoH2 model is demonstrated through a national-scale case study in Laos, incorporating hydrological variability, electrolyser technology options, and spatially resolved demand scenarios. Results indicate that inclusion of hydropower can reduce the minimum levelised cost of hydrogen (LCOH) to US$3.9/kg by 2030, outperforming sites based solely on wind and solar. Additionally, hybrid renewable sites combining hydropower with solar or wind improve cost stability against annual runoff variability; here, solar power offsets reduced hydropower during dry periods. This work delivers the first comprehensive, open-source tool for optimising green hydrogen production in hydropower-rich, data-constrained regions, supporting strategic planning and investment for the global transition to low-carbon hydrogen economies.

   @unpublished{schirren_hydropower_2025,
     title = {Hydropower-Enhanced Spatial Modelling for Green Hydrogen in Data-Constrained Countries},
     author = {Schirren, Lukas and Ward, John and Phommachanh, Sounthisack and Hawkes, Adam and Sridharan, Vignesh},
     year = {2025},
     note = {SSRN Preprint},
     doi = {10.2139/ssrn.5404844},
     url = {https://ssrn.com/abstract=5404844}
   }

2. ERC

   From electrons to molecules: Evaluating green ammonia production as an alternative to electricity exports in Lao PDR

   Vignesh Sridharan, John Ward, Sounthisack Phommachanh, and 4 more authors

   Environmental Research Communications, 2025

   Abs DOI Bib

   Lao PDR’s abundant hydropower resources offer significant potential for green hydrogen and ammonia production. This study evaluates the feasibility of producing green ammonia domestically as an alternative to traditional electricity exports. Using an integrated energy systems modelling approach that combines power system optimisation with hydrogen production and ammonia synthesis pathways, we assess the trade-offs between exporting electricity and converting surplus generation to green ammonia. Our findings indicate that leveraging existing and planned hydropower capacity, Lao PDR could produce competitively priced green ammonia, offering a diversified revenue stream and reducing dependence on volatile electricity export markets. We discuss the infrastructure requirements, cost implications, and policy considerations for this transition.

   @article{sridharan_laos_2025,
     title = {From electrons to molecules: Evaluating green ammonia production as an alternative to electricity exports in Lao PDR},
     author = {Sridharan, Vignesh and Ward, John and Phommachanh, Sounthisack and Nanthavong, Khamphone and Schirren, Lukas and Lubello, Pietro and Hawkes, Adam},
     journal = {Environmental Research Communications},
     year = {2025},
     doi = {10.1088/2515-7620/adfc2f},
     url = {https://doi.org/10.1088/2515-7620/adfc2f},
     publisher = {IOP Publishing}
   }