Subject
renewable energy
16
renewable energy source
14
wind energy
11
electric power generation
10
electricity
8
hydrogen
8
solar energy
7
biomass
6
energy storage
6
energy system
6
battery
5
electric vehicle
5
photovoltaic conversion
5
electric device
4
fuel cell
4
fuel management
4
geothermal energy
4
hydrogen fuel
4
mobility
4
power grid
4
bioconversion to fuel
3
district heating
3
electric power
3
energy conservation
3
energy research
3
energy supply
3
energy technology
3
photovoltaics
3
transport
3
biomass energy production
2
carbon dioxide
2
coupling
2
electric power transmission
2
energy transport
2
fuel
2
solar collector
2
solar electric system
2
solar heating
2
solar thermal power plant
2
urban area
2
wind power plant
2
Environmental economics
1
Production of electric energy or power
1
Renewable energy sources
1
agriculture
1
alcohol
1
big data
1
bioenergetics
1
biofuel
1
biogas
1
more ...