Energy conversion efficiency - wikipedia Energy conversion efficiency This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. ( August 2008 ) Output energy is always lower than input energy Efficiency of Power Plant, World total 2008 Energy conversion efficiency ( η ) is the ratio between the useful output of an energy conversion machine and the input, in energy terms. The input, as well as the useful output may be chemical, electric power, mechanical work, light ( radiation ), or heat. Contents 1 Overview 2 Fuel heating values and efficiency 3 Example of energy conversion efficiency 4 See also 5 References 6 External links Overview Energy conversion efficiency depends on the usefulness of the output. All or part of the heat produced from burning a fuel may become rejected waste heat if, for example, work is the desired output from a thermodynamic cycle. Energy converter is an example of an energy transformation. For example a light bulb falls into the categories energy converter. η = P o u t P i n ( displaystyle eta = ( \frac ( P_ ( mathrm ( out ) ) ) ( P_ ( mathrm ( in ) ) ) ) ) Even though the definition includes the notion of usefulness, efficiency is considered a technical or physical term. Goal or mission oriented terms include effectiveness and efficacy. Generally, energy conversion efficiency is a dimensionless number between 0 and 1.0, or 0 % to 100 %. Efficiencies may not exceed 100 %, e.g., for a perpetual motion machine. However, other effectiveness measures that can exceed 1.0 are used for heat pumps and other devices that move heat rather than convert it. When talking about the efficiency of heat engines and power stations the convention should be stated, i.e., HHV ( a.k.a. Gross Heating Value, etc. ) or LCV ( a.k.a. Net Heating value ), and whether gross output ( at the generator terminals ) or net output ( at the power station fence ) are being considered. The two are separate but both must be stated. Failure to do so causes endless confusion. Related, more specific terms include Electrical efficiency, useful power output per electrical power consumed ; Mechanical efficiency, where one form of mechanical energy ( e.g. potential energy of water ) is converted to mechanical energy ( work ) ; Thermal efficiency or Fuel efficiency, useful heat and / or work output per input energy such as the fuel consumed ; ' Total efficiency ', e.g., for cogeneration, useful electric power and heat output per fuel energy consumed. Same as the thermal efficiency. Luminous efficiency, that portion of the emitted electromagnetic radiation is usable for human vision. Fuel heating values and efficiency In Europe the usable energy content of fuel is typically calculated using the lower heating value ( LHV ) of that fuel, the definition of which assumes that the water vapor produced during fuel combustion ( oxidation ), remains gaseous, and is not condensed to liquid water so the latent heat of vaporization of that water is not usable. Using the LHV, a condensing boiler can achieve a `` heating efficiency '' in excess of 100 % ( this does not violate the first law of thermodynamics as long as the LHV convention is understood, but does cause confusion ). This is because the apparatus recovers part of the heat of vaporization, which is not included in the definition of the lower heating value of fuel. In the U.S. and elsewhere, the higher heating value ( HHV ) is used, which includes the latent heat for condensing the water vapor, and thus the thermodynamic maximum of 100 % efficiency can not be exceeded with HHV 's use. Example of energy conversion efficiency This article is missing information about clear definition of the energy conversion efficiency for light sources. The lighting efficiency is given by the luminous efficacy which does not allow to give a simple percentage without specifying what `` 100 % '' would be. If there is an ISO standard or another reliable source defining the energy conversion efficiency in lighting, please cite it... Please expand the article to include this information. Further details may exist on the talk page. ( May 2012 ) Conversion process Conversion type Energy efficiency Electricity generation Gas turbine Chemical to electrical up to 40 % Gas turbine plus steam turbine ( combined cycle ) Chemical / thermal to electrical up to 60 % Water turbine Gravitational to electrical up to 90 % ( practically achieved ) Wind turbine Kinetic to electrical up to 59 % ( theoretical limit ) Solar cell Radiative to electrical 6 -- 40 % ( technology - dependent, 15 - 20 % most often, 85 -- 90 % theoretical limit ) Fuel cell Chemical to electrical up to 85 % World Electricity generation 2008 Gross output 39 % Net output 33 % Electricity storage Lithium - ion battery Chemical to electrical / reversible 80 -- 90 % Nickel - metal hydride battery Chemical to electrical / reversible 66 % Lead - acid battery Chemical to electrical / reversible 50 -- 95 % Engine / Motor Combustion engine Chemical to kinetic 10 -- 50 % Electric motor Electrical to kinetic 70 -- 99.99 % ( > 200 W ) ; 50 -- 90 % ( 10 -- 200 W ) ; 30 -- 60 % ( < 10 W ) Turbofan Chemical to kinetic 20 - 40 % Natural process Photosynthesis Radiative to chemical up to 6 % Muscle Chemical to kinetic 14 -- 27 % Appliance Household refrigerator Electrical to thermal low - end systems ~ 20 % ; high - end systems ~ 40 -- 50 % Incandescent light bulb Electrical to radiative 0.7 -- 5.1 %, 5 -- 10 % Light - emitting diode ( LED ) Electrical to radiative 4.2 -- 53 % Fluorescent lamp Electrical to radiative 8.0 -- 15.6 %, 28 % Low - pressure sodium lamp Electrical to radiative 15.0 -- 29.0 %, 40.5 % Metal - halide lamp Electrical to radiative 9.5 -- 17.0 %, 24 % Switched - mode power supply Electrical to electrical currently up to 96 % practically Electric shower Electrical to thermal 90 -- 95 % ( multiply with the energy efficiency of electricity generation for comparison with other water - heating systems ) Electric heater Electrical to thermal ~ 100 % ( essentially all energy is converted into heat, multiply with the energy efficiency of electricity generation for comparison with other heating systems ) Others Firearm Chemical to kinetic ~ 30 % (. 300 Hawk ammunition ) Electrolysis of water Electrical to chemical 50 -- 70 % ( 80 -- 94 % theoretical maximum ) See also Cost of electricity by source Energy efficiency ( disambiguation ) EROEI Exergy efficiency Figure of merit Heat of combustion International Electrotechnical Commission Perpetual motion Sensitivity ( electronics ) Solar cell efficiency Coefficient of performance References Cited Jump up ^ IEC / OECD 2008 Energy Balance for World, accessdate 2011 - 06 - 08 Jump up ^ Valøen, Lars Ole and Shoesmith, Mark I. ( 2007 ). The effect of PHEV and HEV duty cycles on battery and battery pack performance ( PDF ). 2007 Plug - in Highway Electric Vehicle Conference : Proceedings. Retrieved 11 June 2010. Jump up ^ `` NiMH Battery Charging Basics ''. PowerStream.com. Jump up ^ PowerSonic, Technical Manual ( PDF ), p. 19, retrieved January 2014 Jump up ^ `` Motivations for Promoting Clean Diesels '' ( PDF ). US Department Of Energy. 2006. Archived from the original ( PDF ) on October 7, 2008. Jump up ^ `` 11.5 Trends in thermal and propulsive efficiency ''. web.mit.edu. Retrieved 2016 - 10 - 26. Jump up ^ Miyamoto K. `` Chapter 1 - Biological energy production ''. Renewable biological systems for alternative sustainable energy production ( FAO Agricultural Services Bulletin - 128 ). Food and Agriculture Organization of the United Nations. Retrieved 2009 - 01 - 04. ^ Jump up to : Luminous efficacy # Lighting efficiency Jump up ^ `` All in 1 LED Lighting Solutions Guide ''. PhilipsLumileds.com. Philips. 2012 - 10 - 04. p. 15. Archived from the original ( PDF ) on 2013 - 03 - 31. Retrieved 2015 - 11 - 18. ^ Jump up to : Light Pollution Handbook. Springer. 2004. General External links The Intelligent Energy - Europe programme : the EU 's tool for funding action towards a more energy intelligent Europe Does it make sense to switch to LED ? Lamps Lighting Concepts Accent lighting Color temperature Efficiency Glare Lamp Light fixture Light pollution Lightbulb socket Task lighting Methods of generation Incandescent Regular Halogen Nernst Parabolic aluminized reflector ( PAR ) Luminescent Fluorescent Fluorescent lamp ( compact ) Fluorescent induction Photoluminescent laser lamp Chemiluminescent Solid - state LED bulb Cathodoluminescent Electron - stimulated Electroluminescent field - induced polymer Combustion Acetylene / Carbide Argand Campfire Candle Carcel Diya Flare Gas Kerosene Lantern Limelight Oil Rushlight Safety Tilley Torch Electric arc Carbon arc Klieg light Yablochkov candle Gas discharge Deuterium arc Neon Plasma Sulfur Xenon arc Xenon flash High - intensity discharge ( HID ) Hydrargyrum medium - arc iodide ( HMI ) Hydrargyrum quartz iodide ( HQI ) Mercury - vapor Metal - halide ceramic Sodium vapor Theatrical Cinematic Floodlight Footlight Gobo Scoop Spotlight ellipsoidal reflector Stage lighting instrument Stationary Aircraft warning Balanced - arm lamp Chandelier Emergency light Gas lighting Gooseneck lamp Intelligent street lighting Light tube Nightlight Neon lighting Pendant light Recessed light Sconce Street light Torchère Track lighting Troffer Mobile Flashlight tactical Glow stick Headlamp ( outdoor ) Lantern Laser pointer Navigation light Searchlight Solar lamp Industrial Scientific Germicidal Grow light Infrared lamp Stroboscope Tanning Display Decorative Aroma lamp Black light Bubble light Christmas lights Crackle tube DJ lighting Electroluminescent wire Lava lamp Marquee Plasma globe Strobe light Related topics Bioluminescence Chemiluminescence Electroluminescence Laser Photoluminescence Radioluminescence Retrieved from `` https://en.wikipedia.org/w/index.php?title=Energy_conversion_efficiency&oldid=808583043 '' Categories : Building engineering Dimensionless numbers of thermodynamics Energy conservation Energy conversion Energy efficiency Hidden categories : Articles needing additional references from August 2008 All articles needing additional references All articles with unsourced statements Articles with unsourced statements from May 2016 Articles with unsourced statements from October 2014 Articles to be expanded from May 2012 Articles with unsourced statements from July 2011 Talk Contents About Wikipedia Беларуская Български Čeština Dansk Deutsch Eesti Español Esperanto فارسی Français 한국어 Հայերեն हिन्दी Italiano עברית Қазақша Latviešu Lietuvių Magyar Nederlands 日本 語 Nordfriisk Norsk Norsk nynorsk Polski Română Русский Simple English Slovenčina Slovenščina ไทย Türkçe Українська 中文 Edit links This page was last edited on 3 November 2017, at 19 : 33. 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Question: what is a comparison of energy output with energy input
Answer: Energy conversion efficiency