I'm Stefan Pfenninger-Lee, Associate Professor of Sustainable Energy Systems at TU Delft's Faculty of Technology, Policy and Management. My research is on the transition to a 100% clean and renewable energy system: understanding the variability of renewables, designing systems that can thrive on this variability, and understanding trade-offs with other dimensions of sustainable development. I also work on scientific software with a particular focus on open, transparent, and reproducible tools.
I have created and maintain open-source scientific software for energy systems research, such as:
- Calliope: A multi-scale energy systems modelling framework
- Renewables.ninja: Simulate the output of wind and solar power plants anywhere in the world
- GSEE: Global Solar Energy Estimator, a fast solar energy simulation library (used in Renewables.ninja)
- Calligraph: Interactively explore and visualise Calliope model results
- modelling-energy-systems: An in-development, open-source textbook on modelling energy systems





