Romain Guillaume Billy

About

I am a researcher at the Industrial Ecology Program.

I make Material Flow Analysis (MFA) and Stock Dynamics models to monitor and simulate metal cycles and their emissions, with a focus on aluminium and battery materials.

In 2024-2025 I am teaching the courses TEP 4285 - Material Flow Analysis and TEP4290 - Modeling of Built Environment Systems.

Background

In my PhD, I was part of Metal Production, an interdisciplinary Centre for Research-based Innovation (SFI). I worked in the Research Domain 5, whose goal was to study the relationship between metals and society.
I was also contributing to the BATMAN project, in which I developed scenarios for material supply, use, and recycling for Li-ion batteries.

I have also been a Teaching Assistant for the courses TEP 4285 - Material Flow Analysis and TEP4290 - Modeling of Built Environment Systems.

Education

PhD in Industrial Ecology, NTNU
Monitoring and simulating material cycles and emissions at multiple scales: Case studies for aluminium
MSc in Industrial Ecology, NTNU

Master thesis: Material Flow Analysis of Extruded Aluminium in French Buildings
MSc in Engineering, Ecole Centrale de Nantes (France)

Publications

2026

Desing, Harald; Passarella, Marinella; Billy, Romain Guillaume; Griebler, Alexander; Langhorst, Moritz; Pogatscher, Stefan; Raabe, Dierk; Remmen, Kirsten; Samberger, Sebastian; Schlesier, Hauke. (2026) Climate stability hinges on energy-material feedback dynamics: Aluminum perspectives. Resources, Conservation and Recycling
Academic article

2025

Rousseau, Lola Sylvie Annie; Næss, Jan Sandstad; Billy, Romain Guillaume; Schön, Peter; Hertwich, Edgar. (2025) Norway's electric vehicle revolution: unveiling greenhouse gas emissions reductions and material use of passenger cars across space and time. Environmental Research Letters
Academic article

2024

Marhoon, Ahmed Mohamed Jaffar Marhoon A; Las Heras Hernandez, Miguel; Billy, Romain Guillaume; Mueller, Daniel Beat; Verones, Francesca. (2024) Mapping Plastic and Plastic Additive Cycles in Coastal Countries: A Norwegian Case Study. Environmental Science and Technology
Academic article
Ravi, Basuhi; Bhuwalka, Karan; Moore, Elizabeth A.; Diersen, Isabel; Malik, Rameen H.; Young, Eric; Billy, Romain Guillaume; Stoner, Robert; Ceder, Gerbrand; Mueller, Daniel Beat. (2024) Clean energy demand must secure sustainable nickel supply. Joule
Academic literature review
Cordhomme, Zoe Angele Adele; Dittrich, Nils Maximilian; Gedde, Kristina Bringedal; Billy, Romain Guillaume; Mueller, Daniel Beat. (2024) Approaching building lifetimes and hazard rates through demolition patterns: Case studies for a historical city center. Journal of Industrial Ecology
Academic article
Barre, Francis Isidore; Billy, Romain Guillaume; Aguilar Lopez, Fernando; Mueller, Daniel Beat. (2024) Limits to graphite supply in a transition to a post-fossil society. Resources, Conservation and Recycling
Academic article
Langhorst, Moritz; Billy, Romain Guillaume; Schwotzer, Christian; Kaiser, Felix; Mueller, Daniel Beat. (2024) Inertia of Technology Stocks: A Technology-Explicit Model for the Transition toward a Low-Carbon Global Aluminum Cycle. Environmental Science and Technology
Academic article

2023

Aguilar Lopez, Fernando; Billy, Romain Guillaume; Mueller, Daniel Beat. (2023) Evaluating strategies for managing resource use in lithium-ion batteries for electric vehicles using the global MATILDA model. Resources, Conservation and Recycling
Academic article
Mueller, Daniel Beat; Billy, Romain Guillaume; Simoni, Mark Uwe; Petavratzi, Evi; Liu, Gang; Rechberger, Helmut; Lundhaug, Maren Cathrine; Cullen, Jonathan. (2023) Maps of the physical economy to inform sustainability strategies.
Non-fiction chapter
Desing, Harald; Widmer, Rolf; Bardi, Ugo; Beylot, Antoine; Billy, Romain Guillaume; Gasser, Martin; Gauch, Marcel; Monfort, Daniel; Mueller, Daniel Beat; Raugei, Marco. (2023) Mobilizing materials to enable a fast energy transition: A conceptual framework. Resources, Conservation and Recycling
Academic article

2022

Billy, Romain Guillaume; Mueller, Daniel Beat. (2022) Aluminium use in passenger cars poses systemic challenges for recycling and GHG emissions. Resources, Conservation and Recycling
Academic article
Langhorst, Moritz; Schwotzer, Christian; Kaiser, Felix; Mueller, Daniel Beat; Billy, Romain Guillaume. (2022) Technology-explicit dynamic material flow analysis of the global aluminium cycle. RWTH Aachen Master's thesis
Master thesis
Genovesi, Sofia; Garofalo, Paolo S.; Mueller, Daniel Beat; Billy, Romain Guillaume; Aguilar Lopez, Fernando. (2022) Graphite for lithium-ion batteries: mineral analysis and global Material Flow Analysis. Master's thesis University of Bologna
Master thesis
Cormery, Marceau; Mueller, Daniel Beat; Billy, Romain Guillaume; Mistry, Mark; Reck, Barbara K.. (2022) Global trade-linked nickel cycle. A Material Flow Analysis (MFA) study considering production and trade of nickel at the global and the country level. NTNU Master thesis
Master thesis
Aguilar Lopez, Fernando; Billy, Romain Guillaume; Mueller, Daniel Beat. (2022) A product–component framework for modeling stock dynamics and its application for electric vehicles and lithium-ion batteries. Journal of Industrial Ecology
Academic article
Billy, Romain Guillaume; Mueller, Daniel Beat; Cullen, Jonathan. (2022) Monitoring and simulating material cycles and emissions at multiple scales: Case studies for aluminium. Norges teknisk-naturvitenskapelige universitet
Doctoral thesis
McNeil, Brent; Mueller, Daniel Beat; Aguilar Lopez, Fernando; Billy, Romain Guillaume. (2022) The Complex Nature of Lithium Extraction - A dynamic material flow analysis to understand supply constraints in the transition to electrified transport. Norges teknisk-naturvitenskapelige universitet
Master thesis
Billy, Romain Guillaume; Monnier, Louis; Nybakke, Even; Isaksen, Morten; Mueller, Daniel Beat. (2022) Systemic approaches for emission reduction in industrial plants based on physical accounting: example for an aluminium smelter. Environmental Science and Technology
Academic article

2021

Young, Eric; Mueller, Daniel Beat; Aguilar Lopez, Fernando; Billy, Romain Guillaume; Petavratzi, Evi; Reck, Barbara K.. (2021) Battery Nickel Bottlenecks: A material flow analysis of the impacts the energy transition will have on the nickel supply system. NTNU Master's thesis
Master thesis
Lauinger, Dirk; Billy, Romain Guillaume; Vasquez, Felipe; Mueller, Daniel Beat. (2021) A general framework for stock dynamics of populations and built and natural environments. Journal of Industrial Ecology
Academic article

2020

Roca Puigros, Marta; Billy, Romain Guillaume; Gerber, Andreas; Wäger, Patrick; Mueller, Daniel Beat. (2020) Pathways toward a carbon-neutral Swiss residential building stock. Buildings & Cities
Academic article

Journal publications

Desing, Harald; Passarella, Marinella; Billy, Romain Guillaume; Griebler, Alexander; Langhorst, Moritz; Pogatscher, Stefan; Raabe, Dierk; Remmen, Kirsten; Samberger, Sebastian; Schlesier, Hauke. (2026) Climate stability hinges on energy-material feedback dynamics: Aluminum perspectives. Resources, Conservation and Recycling
Academic article
Marhoon, Ahmed Mohamed Jaffar Marhoon A; Las Heras Hernandez, Miguel; Billy, Romain Guillaume; Mueller, Daniel Beat; Verones, Francesca. (2024) Mapping Plastic and Plastic Additive Cycles in Coastal Countries: A Norwegian Case Study. Environmental Science and Technology
Academic article
Roca Puigros, Marta; Billy, Romain Guillaume; Gerber, Andreas; Wäger, Patrick; Mueller, Daniel Beat. (2020) Pathways toward a carbon-neutral Swiss residential building stock. Buildings & Cities
Academic article
Billy, Romain Guillaume; Mueller, Daniel Beat. (2022) Aluminium use in passenger cars poses systemic challenges for recycling and GHG emissions. Resources, Conservation and Recycling
Academic article
Ravi, Basuhi; Bhuwalka, Karan; Moore, Elizabeth A.; Diersen, Isabel; Malik, Rameen H.; Young, Eric; Billy, Romain Guillaume; Stoner, Robert; Ceder, Gerbrand; Mueller, Daniel Beat. (2024) Clean energy demand must secure sustainable nickel supply. Joule
Academic literature review
Lauinger, Dirk; Billy, Romain Guillaume; Vasquez, Felipe; Mueller, Daniel Beat. (2021) A general framework for stock dynamics of populations and built and natural environments. Journal of Industrial Ecology
Academic article
Aguilar Lopez, Fernando; Billy, Romain Guillaume; Mueller, Daniel Beat. (2022) A product–component framework for modeling stock dynamics and its application for electric vehicles and lithium-ion batteries. Journal of Industrial Ecology
Academic article
Cordhomme, Zoe Angele Adele; Dittrich, Nils Maximilian; Gedde, Kristina Bringedal; Billy, Romain Guillaume; Mueller, Daniel Beat. (2024) Approaching building lifetimes and hazard rates through demolition patterns: Case studies for a historical city center. Journal of Industrial Ecology
Academic article
Aguilar Lopez, Fernando; Billy, Romain Guillaume; Mueller, Daniel Beat. (2023) Evaluating strategies for managing resource use in lithium-ion batteries for electric vehicles using the global MATILDA model. Resources, Conservation and Recycling
Academic article
Desing, Harald; Widmer, Rolf; Bardi, Ugo; Beylot, Antoine; Billy, Romain Guillaume; Gasser, Martin; Gauch, Marcel; Monfort, Daniel; Mueller, Daniel Beat; Raugei, Marco. (2023) Mobilizing materials to enable a fast energy transition: A conceptual framework. Resources, Conservation and Recycling
Academic article
Barre, Francis Isidore; Billy, Romain Guillaume; Aguilar Lopez, Fernando; Mueller, Daniel Beat. (2024) Limits to graphite supply in a transition to a post-fossil society. Resources, Conservation and Recycling
Academic article
Langhorst, Moritz; Billy, Romain Guillaume; Schwotzer, Christian; Kaiser, Felix; Mueller, Daniel Beat. (2024) Inertia of Technology Stocks: A Technology-Explicit Model for the Transition toward a Low-Carbon Global Aluminum Cycle. Environmental Science and Technology
Academic article
Rousseau, Lola Sylvie Annie; Næss, Jan Sandstad; Billy, Romain Guillaume; Schön, Peter; Hertwich, Edgar. (2025) Norway's electric vehicle revolution: unveiling greenhouse gas emissions reductions and material use of passenger cars across space and time. Environmental Research Letters
Academic article
Billy, Romain Guillaume; Monnier, Louis; Nybakke, Even; Isaksen, Morten; Mueller, Daniel Beat. (2022) Systemic approaches for emission reduction in industrial plants based on physical accounting: example for an aluminium smelter. Environmental Science and Technology
Academic article

Part of book/report

Mueller, Daniel Beat; Billy, Romain Guillaume; Simoni, Mark Uwe; Petavratzi, Evi; Liu, Gang; Rechberger, Helmut; Lundhaug, Maren Cathrine; Cullen, Jonathan. (2023) Maps of the physical economy to inform sustainability strategies.
Non-fiction chapter

Student thesis or dissertation

Langhorst, Moritz; Schwotzer, Christian; Kaiser, Felix; Mueller, Daniel Beat; Billy, Romain Guillaume. (2022) Technology-explicit dynamic material flow analysis of the global aluminium cycle. RWTH Aachen Master's thesis
Master thesis
Genovesi, Sofia; Garofalo, Paolo S.; Mueller, Daniel Beat; Billy, Romain Guillaume; Aguilar Lopez, Fernando. (2022) Graphite for lithium-ion batteries: mineral analysis and global Material Flow Analysis. Master's thesis University of Bologna
Master thesis
Young, Eric; Mueller, Daniel Beat; Aguilar Lopez, Fernando; Billy, Romain Guillaume; Petavratzi, Evi; Reck, Barbara K.. (2021) Battery Nickel Bottlenecks: A material flow analysis of the impacts the energy transition will have on the nickel supply system. NTNU Master's thesis
Master thesis
Cormery, Marceau; Mueller, Daniel Beat; Billy, Romain Guillaume; Mistry, Mark; Reck, Barbara K.. (2022) Global trade-linked nickel cycle. A Material Flow Analysis (MFA) study considering production and trade of nickel at the global and the country level. NTNU Master thesis
Master thesis
Billy, Romain Guillaume; Mueller, Daniel Beat; Cullen, Jonathan. (2022) Monitoring and simulating material cycles and emissions at multiple scales: Case studies for aluminium. Norges teknisk-naturvitenskapelige universitet
Doctoral thesis
McNeil, Brent; Mueller, Daniel Beat; Aguilar Lopez, Fernando; Billy, Romain Guillaume. (2022) The Complex Nature of Lithium Extraction - A dynamic material flow analysis to understand supply constraints in the transition to electrified transport. Norges teknisk-naturvitenskapelige universitet
Master thesis

Teaching

Courses

Outreach