- Energy, general 77
- Biomaterials 59
- Materials Engineering 59
- Metallic Materials 59
- Nanoscale Science and Technology 59
- Physical Chemistry 59
- Energy Systems 10
- Energy Policy, Economics and Management 7
- Energy Storage 7
- Renewable and Green Energy 7
- Environmental Science and Engineering 5
- Geoengineering, Foundations, Hydraulics 4
- Geophysics/Geodesy 4
- Geotechnical Engineering & Applied Earth Sciences 4
- Aerospace Technology and Astronautics 3
- Control and Systems Theory 3
- Space Sciences (including Extraterrestrial Physics, Space Exploration and Astronautics) 3
- Electrical Engineering 2
- Climate Change 1