what is the most efficent non-nuclear energy conversion?
413623
Eat the bugs. Your body is unbelievably efficient in converting food to energy.
599950
Are you looking for something like this, a homemade wind turbine to generate electricity?\n\nhttp://www.otherpower.com/17page1.html
544463
solar/wind power and electric vehicles. natural, renewable, no pollution, and noone has a monopoly on sunlight and wind.
1142280
in North America the average power of the solar radiation lies somewhere between 125 and 375 W/m², between 3 and 9 kWh/m²/day. [3]\n\nIt should be noted that this is the maximum available power, and not the power delivered by solar power technology. For example photovoltaic panels currently have an efficiency of ca. 15% and, hence, a solar panel delivers 19 to 56 W/m² or 0.45-1.35 kWh/m²/day (annual day and night average).\n\n\nGaAs multijunction devices are the most efficient solar cells to date, reaching as high as 39% efficiency[9]. They are also some of the most expensive cells per unit area (up to US$40/cm2).
961600
In the laws of thermodynamics, it is stated that energy can not be created nor destroyed, but may be converted from one form of energy to another.  So, it might be better to ask how does one convert various forms of energy into thermal energy?\n\nWell, in the world of HVAC, we can burn a hydrocarbon fuel such as oil or gas (energy), and the products of the combustion process will be heat energy, light, water vapor, carbon dioxide, carbon monoxide (we try to create very little of this stuff), and vaporous and particulate matter (smoke .. again, we try to create very little of this stuff too).  The heat and light energy can be placed next to, or mixed within substances that have a lower temperature, and thus heat energy will flow from the hotter products of combustion to areas and substances that are cooler (heat energy always travels from areas of higher temperature to areas of lower temperature).  If a heat exchanger is used, the above products of combustion will be on one side of the heat exchanger, and substances such as cool air or relatively cool water will be on the other side, heat energy will flow from the hot products of combustion to and through the cooler heat exchanger material, and then will flow from the heat exchanger to the even cooler substance your trying to heat such as the water or air.\n\nElectrical energy can be converted to heat energy (thermal energy) by passing a current through a device that has resistance (a resistor).  It takes electrical pressure (voltage) to push the electrons through a resistive material, but any flow of electrons through the resistive material will cause the material to heat up.  The formula P = I x E applies here and “P” will be the rate of power measured in watts, “I” stands for flow of electrons measured in amps, and “E” is electrical pressure measured in volts.  To convert watt hours to BTU's (a watt hour can be a watt that is running for one full hour), you multiply watt hours times 3.413 (I have seen conversion factors ranging from 3.412 to 3.415, I’m not sure what the exact conversion is, but any number in this range will be pretty accurate).\n\nThere are other ways of converting other forms of energy to heat energy, including mechanical energy (friction), other chemical reactions, solar radiation, nuclear reactions  etc.
722421
Silicon solar cell efficiencies vary from 6% for amorphous silicon-based solar cells to 30% or higher with multiple-junction research lab cells. Solar cell energy conversion efficiencies for commercially available mc-Si solar cells are around 12%. The highest efficiency cells have not always been the most economical -- for example a 30% efficient multijunction cell based on exotic materials such as gallium arsenide or indium selenide and produced in low volume might well cost one hundred times as much as an 8% efficient amorphous silicon cell in mass production, while only delivering a little under four times the electrical power.
283028
Photosynthesis generally takes light, CO2 & water and makes sugars.  These sugars are chemically converted in to food, propane, methanol, ethanol, coal, oil, wood and all the other fossil fuels and orgnic compounds on the earth, through natural, geologic, and/or manmade processes.  At every step of each process, energy is lost.  To gain usable energy, other than in biologic processes, requires burning something, and using the expansion of heated gases to create physical force (motion), or then using physical force to drive a generator to create electrical current.    \n\nWe do not currently have an effecient method of making electicity using incoming Solar radiation.  Current solar cells convert a small percentage of one section of the electromagnetic spectrum into electric current.\n\nHope this helps.
205169
The greatest technological challenge of the 21st century is to meet energy demand in an environmentally sustainable way.  Nuclear energy is a carbon free energy; however, current fission technology leaves a deadly legacy - radioactive waste that is toxic for tens of thousands of years.  To put the energy demands of humans in perspective with nuclear energy, please see the lecture by Nate Lewis (California Institute of Technology).  In 2006, humans are consuming energy at a rate of about 14TW (14 trillion watts).  Using current technology, in order to generate 10TW of energy, we would have to build a new reactor every single day for the next 50 years.  This would be a monumental effort in stupidity and futility.  Furthermore, this would not meet growing energy demand, which is predicted to be ~28TW in the year 2050.  The clearest alternatives are wind energy and solar energy.  Practically, wind energy used globally can potentially provide ~2TW energy, meaning that solar energy is going to be our primary energy source.  The energy that strikes the Earth in 1 hour as sunlight is enough to provide humanity's energy needs for 1 year (~14TW).  However, this energy is diffuse, and we still need to develop low cost, efficient methods to convert solar energy to fuels and electricity. Research is progressing rapidly in this topic.  The world needs to committ massive resources to this right now.  \n\nThe second part of your question relates to cold fusion.  Interestingly, fusion is the source of sunlight, so using solar energy, is in a way, using fusion energy (we don't have to worry about the problems of containment and generating fusion pressures and temperatures).  There are a few research projects around the world that are working on finding useful methods for controlling fusion reactions for energy.  Perhaps the most well known involves a giant room with thousands of high energy lasers that are focused at a pelletized source of fusionable material.  In this scheme, the energy input from the lasers initiates fusion.  This technology is promising, but is far from being economical.  Research efforts should continue.
70676
Natural gas is a very good source for energy, but it is non-renewable with our current technology. \n\nHydro-electric is a viable energy source for electricty. It will always be available unless the water cycle ends.\n\nCoal is a good source for heat and power, but it does have some polluting characteristics in its natural state.\n\nNuclear is good for electricity production, steam generation and heat (from steam), it does leave residual waste, that is more concentrated radioactivity than what occurs naturally.\n\nFuel cells require power to produce but they work very well. They use readily available materials and can be scaled to the power output that is needed.\n\nGeothermal is good for heating houses and on a large scale in some areas for producing electricity. It is also a renewable power source.\n\nWind and solar are two more options that are becoming readily available for the end user. They are generally coupled with a battery system for calm periods of weather and night time.
164385
neontech saves energy, for more details visit:\nhowstuffworks.com
435767
most common way is not through elecrolysis, but extraction from fossil fuels:  Here is a list of the ways...notice in every case a large amount of energy is input-and in most cases this energy comes from coal burning  for electricity or oil...\nHydrogen can be produced using a variety of domestic energy resources - fossil fuels, such as coal and natural gas, with carbon capture and sequestration; renewables, such as biomass, and renewable energy technologies, including solar, wind, geothermal, and hydropower; and nuclear power. Specific technologies and processes are described below.\n\nThermochemical Processes\nSteam methane reforming: In this process, high-temperature steam is used to extract hydrogen from a methane source such as natural gas. This is the most common method of producing hydrogen; about 95 percent of the hydrogen we use today in the United States is produced using this process. \nPartial oxidation: Scientists are exploring a process that produces hydrogen by simultaneously separating oxygen from air and partially oxidizing methane. \nOther thermal processes: Other processes include (1) splitting water using heat from a solar concentrator, and (2) gasifying or burning biomass (i.e., biological material, such as plants or agricultural waste) to generate a bio-oil or gas, which is then reformed to produce hydrogen. \nElectrolytic Processes\nElectrolysis: In electrolysis, electricity is used to separate water (H2O) into hydrogen and oxygen. Current electrolysis systems are very energy intensive. The challenge is to develop low cost and more energy efficient electrolysis technologies. \nPhotolytic Processes\nPhotolytic methods: In photolysis, sunlight is used to split water. Two photolytic processes are being explored: (1) photobiological methods, in which microbes, when exposed to sunlight, split water to produce hydrogen, and (2) photoelectrolysis, in which semi-conductors, when exposed to sunlight and submersed in water, generate enough electricity to produce hydrogen by splitting the water.
619351
i think wikipedia is the best for the purpose\n\nhttp://en.wikipedia.org/wiki/Thermal_energy
720553
There are many ways to take advantage of the energy produced by the sun.  A good place to start is with a passive solar energy water heater.  They are inexpensive to install and easy to maintain.  The simplest ones use the radiant energy of the sun and convert that to thermal energy using a material that absorbs the light instead of reflecting it, in layman's terms, something black.  \n\nPhotovoltaic (solar cell) systems convert sunlight directly into electricity. A solar or Photovoltaic cell consists of semiconducting material that absorbs the sunlight. The solar energy knocks electrons loose from their atoms in a semiconductor, allowing the electrons to flow through the material to produce electricity.\n\nFor a more in-depth explanation of photovoltaic technology try this site.
324403
There is no such thing as non-renewable energy.  Energy is simply converted from one form to another and never actually gets 'used'.\n\nThere are non-renewable SOURCES of energy however and other answerers have pointed these out.\nHydrocarbons, like coal, oil and gas are considered non-renewable because once you have converted their (stored) chemical energy in to heat energy by burning them, you will have to wait several million years before the energy is stored back in a chemical form for you to burn again.\nWind power is considered renewable since wind is a form of mechanical energy which is converted thermal energy from the sun.  We use wind turbines to control the mechanical energy of the wind and convert it into electrical energy.  The sun provides more thermal energy, which makes more wind and so the source of energy is renewed on a useful timescale.\n\nMost energy on Earth comes from the sun.  Wind is driven by the sun as I have explained.  Solar energy is obviously sun powered.  Chemical energy sources like wood, coal, gas, etc also come from the sun since plants capture the solar energy and store it in their structure as chemical energy.  This same energy is what is released by burning.\nThe most notable source of non-sun derived energy on Earth is that of the tides.  Gravitational effects between the Earth and the moon (alright, and the sun a bit) cause the tides.  Gravitational energy converted to mechanical energy.  We can use this as a renewable source as well.\n\n<flight of fancy>\nIt is theoretically possible to have so many turbines extracting energy from the wind that there isn't enough left over to keep the winds blowing, which would have rather a startling effect on regional climates.  Turn the turbnes off however and the sun would soon start things up again.\n</flight of fancy>
509058
No way.  And the evidence is easy to find, too.  Plug in a power converter and run something off it for a while, then put your hand on the converter -- it's hot, right?\n\nThat heat is *wasted energy* -- converting electricity from one voltage to another requires work to be done, and that work generates heat, which is the indication of the inherent inefficiences of the process.  If you then reconvert the electricity to 120V, you will experience a second inefficiency, evidenced as more heat lost.
29387
Nuclear power.  If not a reactor then a thermo-isotopic core.  \n\nIt takes 10 yrs to get there, a long time for batteries.\nNot only that, but that distance, the sun is just a bright star, so that rules out solar power.
284015
You cannot.  The law of conservation of energy states in lay language that energy can be neither created nor destroyed.  Therefore, getting more work out of a machine than is put into it is not possible.  In practical terms, even 100% efficiency, which would be getting an equal amount of work output, is not possible since some energy will always be lost due to forces such as friction.  Two terms describing the state where work output is greater than work input are "perpetual motion" and "free energy."  Unfortunately, neither one can exist.