Energy utilization 227 Energy efficiency 71 Energy-consumption 53 Sustainable development 34 Energy 27 Carbon dioxide 20 Energy conservation 20 China 16 Economic analysis 15 Costs 13 Economic and social effects 13 Energy consumption 13 Internet of things 13 Life cycle 13 energy consumption 13 Greenhouse gases 12 Sensor nodes 12 energy efficiency 12 Carbon 11 Environmental impact 11 Renewable energy resources 11 Genetic algorithms 10 Renewable energies 10 Climate change 9 Digital storage 9 Energy policy 9 Gas emissions 9 Global warming 9 Reduce energy consumption 9 Buildings 8