Geothermal energy 3 Wave energy Wind energy 3 Fossil fuels 2 Hydro electricity 2 Solar energy 2 Bio energy 1 Bio gas energy 1 Bioenergy 1 Biomass energy 1 Electric power sector 1 Energy from waste 1 Fossil energy 1 Hydropower 1 Non conventional energy 1 Nuclear energy 1 Nuclear power 1 Ocean waves energy 1 Solar thermal energy 1 Sustainable energy 1 Thermal energy conversion 1 Tidal energy 1 Tidal power 1 Tide energy 1 hydro thermal energy 1