Classification
CNWK - Electric batteries
EHA - Renewable energy sources
4
FJB - Electric materials
4
TEJ - Electric devices, mechanical devices, magnets, dielectrics
4
CNW - Electrochemical energy production and conversion
2
EBA - Energy production, energy technology
2
CXX - Hydrogen production - chemistry and technology
1
ESB - Hydrogen energy
1
ETC - Energy conversion
1
ETF - Fuel cells - general
1