Publications
2026
- PreprintBeyond hard-to-abate: Matching models to transition bottlenecksLukas Schirren, Leander Müller, Alaa Al Khourdajie, and 3 more authors2026EarthArXiv Preprint
In energy-intensive industry, the difficulty of decarbonising is not a uniform property of the emissions involved but a property of the pathway, conditional on identifiable bottlenecks at three interlocking levels. At the process level, heterogeneous products and coupled processes multiply the low-carbon option space. At the firm level, financing premiums and coordination failures across the supply chain govern who invests and when. At the sector level, competition is shaped by trade policy and security of supply, and the politics of the transition by the regional employment these industries sustain. These bottlenecks reinforce one another across levels, so the difficulty becomes a property of the configuration rather than of any single constraint. Representing this configuration demands matching the "right" model to each bottleneck. Dominant optimisation frameworks are built for system-level analyses and resolve process detail well but collapse firm heterogeneity into a single planner and treat demand and global competition as exogenous rather than as co-evolving with the transition. Path-dependent first-mover investments and their regional employment effects fall outside cost-optimising frameworks with exogenous demand, leaving the firm level largely missing. Across sectors, shared inputs such as hydrogen and methanol create reinforcing learning curves that only models with endogenous, shared learning capture. We therefore argue for a shift in framing, from hard-to-abate, a property of emissions, to hard-to-transition, a property of the pathway, where viable solutions exist but have not been deployed. The reframe converts the problem into an actionable task, matching each bottleneck to a model that can address it.
@unpublished{schirren_beyond_2026, title = {Beyond hard-to-abate: Matching models to transition bottlenecks}, author = {Schirren, Lukas and Müller, Leander and Al Khourdajie, Alaa and Gast, Lukas and Egli, Florian and Hawkes, Adam}, year = {2026}, note = {EarthArXiv Preprint}, doi = {10.31223/X5CF8B}, url = {https://doi.org/10.31223/X5CF8B} } - Geo-X: Generalised Geospatial Software for Production of Green CommoditiesMiguel Sanchez-Lopez, Samiyha Naqvi, Alycia Leonard, and 2 more authors2026
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
- PreprintHydropower-Enhanced Spatial Modelling for Green Hydrogen in Data-Constrained CountriesLukas Schirren, John Ward, Sounthisack Phommachanh, and 2 more authors2025SSRN Preprint
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} } - From electrons to molecules: Evaluating green ammonia production as an alternative to electricity exports in Lao PDREnvironmental Research Communications, 2025
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} }