<Table> <Tr> <Th> Conversion process </Th> <Th> Conversion type </Th> <Th> Energy efficiency </Th> </Tr> <Tr> <Td colspan="3"> Electricity generation </Td> </Tr> <Tr> <Td> Gas turbine </Td> <Td> Chemical to electrical </Td> <Td> up to 40 % </Td> </Tr> <Tr> <Td> Gas turbine plus steam turbine ( combined cycle ) </Td> <Td> Chemical / thermal to electrical </Td> <Td> up to 60 % </Td> </Tr> <Tr> <Td> Water turbine </Td> <Td> Gravitational to electrical </Td> <Td> up to 90 % ( practically achieved ) </Td> </Tr> <Tr> <Td> Wind turbine </Td> <Td> Kinetic to electrical </Td> <Td> up to 59 % ( theoretical limit ) </Td> </Tr> <Tr> <Td> Solar cell </Td> <Td> Radiative to electrical </Td> <Td> 6 -- 40 % ( technology - dependent , 15 - 20 % most often , 85 -- 90 % theoretical limit ) </Td> </Tr> <Tr> <Td> Fuel cell </Td> <Td> Chemical to electrical </Td> <Td> up to 85 % </Td> </Tr> <Tr> <Td> World Electricity generation 2008 </Td> <Td> Gross output 39 % </Td> <Td> Net output 33 % </Td> </Tr> <Tr> <Td colspan="3"> Electricity storage </Td> </Tr> <Tr> <Td> Lithium - ion battery </Td> <Td> Chemical to electrical / reversible </Td> <Td> 80 -- 90 % </Td> </Tr> <Tr> <Td> Nickel - metal hydride battery </Td> <Td> Chemical to electrical / reversible </Td> <Td> 66 % </Td> </Tr> <Tr> <Td> Lead - acid battery </Td> <Td> Chemical to electrical / reversible </Td> <Td> 50 -- 95 % </Td> </Tr> <Tr> <Td colspan="3"> Engine / motor </Td> </Tr> <Tr> <Td> Combustion engine </Td> <Td> Chemical to kinetic </Td> <Td> 10 -- 50 % </Td> </Tr> <Tr> <Td> Electric motor </Td> <Td> Electrical to kinetic </Td> <Td> 70 -- 99.99 % ( > 200 W ) ; 50 -- 90 % ( 10 -- 200 W ) ; 30 -- 60 % ( < 10 W ) </Td> </Tr> <Tr> <Td> Turbofan </Td> <Td> Chemical to kinetic </Td> <Td> 20 - 40 % </Td> </Tr> <Tr> <Td colspan="3"> Natural process </Td> </Tr> <Tr> <Td> Photosynthesis </Td> <Td> Radiative to chemical </Td> <Td> up to 6 % </Td> </Tr> <Tr> <Td> Muscle </Td> <Td> Chemical to kinetic </Td> <Td> 14 -- 27 % </Td> </Tr> <Tr> <Td colspan="3"> Appliance </Td> </Tr> <Tr> <Td> Household refrigerator </Td> <Td> Electrical to thermal </Td> <Td> low - end systems ~ 20 % ; high - end systems ~ 40 -- 50 % </Td> </Tr> <Tr> <Td> Incandescent light bulb </Td> <Td> Electrical to radiative </Td> <Td> 0.7 -- 5.1 % , 5 -- 10 % </Td> </Tr> <Tr> <Td> Light - emitting diode ( LED ) </Td> <Td> Electrical to radiative </Td> <Td> 4.2 -- 53 % </Td> </Tr> <Tr> <Td> Fluorescent lamp </Td> <Td> Electrical to radiative </Td> <Td> 8.0 -- 15.6 % , 28 % </Td> </Tr> <Tr> <Td> Low - pressure sodium lamp </Td> <Td> Electrical to radiative </Td> <Td> 15.0 -- 29.0 % , 40.5 % </Td> </Tr> <Tr> <Td> Metal - halide lamp </Td> <Td> Electrical to radiative </Td> <Td> 9.5 -- 17.0 % , 24 % </Td> </Tr> <Tr> <Td> Switched - mode power supply </Td> <Td> Electrical to electrical </Td> <Td> currently up to 96 % practically </Td> </Tr> <Tr> <Td> Electric shower </Td> <Td> Electrical to thermal </Td> <Td> 90 -- 95 % ( multiply with the energy efficiency of electricity generation for comparison with other water - heating systems ) </Td> </Tr> <Tr> <Td> Electric heater </Td> <Td> Electrical to thermal </Td> <Td> ~ 100 % ( essentially all energy is converted into heat , multiply with the energy efficiency of electricity generation for comparison with other heating systems ) </Td> </Tr> <Tr> <Td colspan="3"> Others </Td> </Tr> <Tr> <Td> Firearm </Td> <Td> Chemical to kinetic </Td> <Td> ~ 30 % (. 300 Hawk ammunition ) </Td> </Tr> <Tr> <Td> Electrolysis of water </Td> <Td> Electrical to chemical </Td> <Td> 50 -- 70 % ( 80 -- 94 % theoretical maximum ) </Td> </Tr> </Table>
<Table> <Tr> <Th> Conversion process </Th> <Th> Conversion type </Th> <Th> Energy efficiency </Th> </Tr> <Tr> <Td colspan="3"> Electricity generation </Td> </Tr> <Tr> <Td> Gas turbine </Td> <Td> Chemical to electrical </Td> <Td> up to 40 % </Td> </Tr> <Tr> <Td> Gas turbine plus steam turbine ( combined cycle ) </Td> <Td> Chemical / thermal to electrical </Td> <Td> up to 60 % </Td> </Tr> <Tr> <Td> Water turbine </Td> <Td> Gravitational to electrical </Td> <Td> up to 90 % ( practically achieved ) </Td> </Tr> <Tr> <Td> Wind turbine </Td> <Td> Kinetic to electrical </Td> <Td> up to 59 % ( theoretical limit ) </Td> </Tr> <Tr> <Td> Solar cell </Td> <Td> Radiative to electrical </Td> <Td> 6 -- 40 % ( technology - dependent , 15 - 20 % most often , 85 -- 90 % theoretical limit ) </Td> </Tr> <Tr> <Td> Fuel cell </Td> <Td> Chemical to electrical </Td> <Td> up to 85 % </Td> </Tr> <Tr> <Td> World Electricity generation 2008 </Td> <Td> Gross output 39 % </Td> <Td> Net output 33 % </Td> </Tr> <Tr> <Td colspan="3"> Electricity storage </Td> </Tr> <Tr> <Td> Lithium - ion battery </Td> <Td> Chemical to electrical / reversible </Td> <Td> 80 -- 90 % </Td> </Tr> <Tr> <Td> Nickel - metal hydride battery </Td> <Td> Chemical to electrical / reversible </Td> <Td> 66 % </Td> </Tr> <Tr> <Td> Lead - acid battery </Td> <Td> Chemical to electrical / reversible </Td> <Td> 50 -- 95 % </Td> </Tr> <Tr> <Td colspan="3"> Engine / motor </Td> </Tr> <Tr> <Td> Combustion engine </Td> <Td> Chemical to kinetic </Td> <Td> 10 -- 50 % </Td> </Tr> <Tr> <Td> Electric motor </Td> <Td> Electrical to kinetic </Td> <Td> 70 -- 99.99 % ( > 200 W ) ; 50 -- 90 % ( 10 -- 200 W ) ; 30 -- 60 % ( < 10 W ) </Td> </Tr> <Tr> <Td> Turbofan </Td> <Td> Chemical to kinetic </Td> <Td> 20 - 40 % </Td> </Tr> <Tr> <Td colspan="3"> Natural process </Td> </Tr> <Tr> <Td> Photosynthesis </Td> <Td> Radiative to chemical </Td> <Td> up to 6 % </Td> </Tr> <Tr> <Td> Muscle </Td> <Td> Chemical to kinetic </Td> <Td> 14 -- 27 % </Td> </Tr> <Tr> <Td colspan="3"> Appliance </Td> </Tr> <Tr> <Td> Household refrigerator </Td> <Td> Electrical to thermal </Td> <Td> low - end systems ~ 20 % ; high - end systems ~ 40 -- 50 % </Td> </Tr> <Tr> <Td> Incandescent light bulb </Td> <Td> Electrical to radiative </Td> <Td> 0.7 -- 5.1 % , 5 -- 10 % </Td> </Tr> <Tr> <Td> Light - emitting diode ( LED ) </Td> <Td> Electrical to radiative </Td> <Td> 4.2 -- 53 % </Td> </Tr> <Tr> <Td> Fluorescent lamp </Td> <Td> Electrical to radiative </Td> <Td> 8.0 -- 15.6 % , 28 % </Td> </Tr> <Tr> <Td> Low - pressure sodium lamp </Td> <Td> Electrical to radiative </Td> <Td> 15.0 -- 29.0 % , 40.5 % </Td> </Tr> <Tr> <Td> Metal - halide lamp </Td> <Td> Electrical to radiative </Td> <Td> 9.5 -- 17.0 % , 24 % </Td> </Tr> <Tr> <Td> Switched - mode power supply </Td> <Td> Electrical to electrical </Td> <Td> currently up to 96 % practically </Td> </Tr> <Tr> <Td> Electric shower </Td> <Td> Electrical to thermal </Td> <Td> 90 -- 95 % ( multiply with the energy efficiency of electricity generation for comparison with other water - heating systems ) </Td> </Tr> <Tr> <Td> Electric heater </Td> <Td> Electrical to thermal </Td> <Td> ~ 100 % ( essentially all energy is converted into heat , multiply with the energy efficiency of electricity generation for comparison with other heating systems ) </Td> </Tr> <Tr> <Td colspan="3"> Others </Td> </Tr> <Tr> <Td> Firearm </Td> <Td> Chemical to kinetic </Td> <Td> ~ 30 % (. 300 Hawk ammunition ) </Td> </Tr> <Tr> <Td> Electrolysis of water </Td> <Td> Electrical to chemical </Td> <Td> 50 -- 70 % ( 80 -- 94 % theoretical maximum ) </Td> </Tr> </Table>
what percentage of energy usage by muscles is converted into heat energy
what percentage of energy usage by muscles is converted into heat energy
14 -- 27 %
14 -- 27 %