power engineering 20 compressors 6 unconventional energy sources 6 combustion 6 biofuels 5 power stations 5 combustion physics 5 more ... biomass 4 geothermal energy sources 4 gas turbines 4 heat-generating plants 4 ventilators 4 industrial fans 3 internal combustion motors 3 heating plants 3 solar energy sources 2 energetické úspory 2 management 2 environment protection 2 gas pipes 2 industry 2 computer technology 2 accumulator batteries 1 alternativní energetické zdroje 1 automatic control 1 cooling 1 diagnostics 1 effectiveness 1 long-distance electric lines 1 elektrification systems 1 less ...