Energy policy Power resources 25 Environmental aspects 23 Energy consumption 20 Government policy 19 Petroleum industry and trade 18 Energy development 17 more ... Renewable energy sources 16 Economic aspects 14 Energy industries 14 Political aspects 13 Environmental policy 10 History 10 Energy conservation 9 Climatic changes 8 Sustainable development 8 Energy security 7 Forecasting 7 Foreign relations 7 Petroleum reserves 7 Carbon dioxide mitigation 6 Electric utilities 6 Foreign economic relations 5 Economic development 4 Economic policy 4 Electric power consumption 4 Gas industry 4 Biomass energy 3 Cities and towns 3 City planning 3 less ...