- Renewable and Green Energy 16
- Energy Storage 12
- Energy Systems 12
- Fossil Fuels (incl. Carbon Capture) 12
- Sustainable Development 12
- Biotechnology 2
- Characterization and Evaluation of Materials 2
- Environment, general 2
- Environmental Engineering/Biotechnology 2
- Industrial Chemistry/Chemical Engineering 2
- Microbiology 2
- Physical Chemistry 2
- Plant Breeding/Biotechnology 2