Energy_sources_能源简介英文资料.ppt

energy sources,王逸 20110857 茅以升4班,primary energy resources,primary energy is an energy form found in nature that has not been subjected to any conversion or transformation process. such as,fossil fuels energy oil coal natural gas,wind energy solar energy geothermal energy,secondary energy resources,secondary energy refers to the more convenient forms of energy which are transformed from other, primary, energy sources through energy conversion processes.,the two most well-known energy carriers are: electricity hydrogen they are usually renewable sources,wind energy,wind power,wind power harnesses the power of the wind to propel the blades of wind turbines. these turbines cause the rotation of magnets, which creates electricity. wind towers are usually built together on wind farms.,hydro energy,hydro energy,in hydro energy, the gravitational descent of a river is compressed from a long run to a single location with a dam or a flume.,solar energy,solar power,solar power involves using solar cells to convert sunlight into electricity, using sunlight hitting solar thermal panels to convert sunlight to heat water or air, using sunlight hitting a parabolic mirror to heat water (producing steam), or using sunlight entering windows for passive solar heating of a building.,geothermal energy,geothermal energy,geothermal energy harnesses the heat energy present underneath the earth, and is capable of supplying all of our energy.,fossil fuels energy,fossil fuels,fossil fuels are fuels formed by natural processes such as anaerobic decomposition of buried dead organisms. such as oil , coal and natural gas,secondary energy resources,electricity,electricity,electricity grids are the networks used to transmit and distribute power from production source to end user, when the two may be hundreds of kilometres away.,battery,batteries are used to store energy in a chemical form. as an alternative energy, batteries can be used to store energy in battery electric vehicles.,hydrogen energy,hydrogen,a fuel cell can convert the chemicals hydrogen and oxygen into water, and in the process, electricity is produced. hydrogen can be burned (less efficiently than in a fuel cell) in an internal combustion engine.,renewable energy and non-renewable energy resource,renewable energy,renewable energy is energy that comes from resources which are continually replenished such as sunlight, wind, rain,tides, waves and geothermal heat. about 16% of global final energy consumption comes from renewable resources,how to increase the enfficiency,second law of thermodynamics kelvin statement it is impossible, by means of inanimate material agency, to derive mechanical effect from any portion of matter by cooling it below the temperature of the coldest of the surrounding objects. clausius statement heat can never pass from a colder to a warmer body without some other change, connected therewith, occurring at the same time. the two statements are equaled,a carnot cycle graph,the efficiency can be increased by increasing the