太阳能英语演讲ppt

Solar Energy,Outline,BackgroundApplicationPrincipleUtilizationAutomatic solar tracking deviceOutlook,Background,nuclar power,coal,oil,Advantage:Utilization is high,can be used for most of our life and make Social progressDisadvantage:Nonrenewable,Pollution of the environment Monopoly,Limited,Natural gas,The time that energy can be used:Oil:42 YNatural gas:67 YCoal:200 Y,Three thousand years ago ,humans began to use solar energy Indirectly.Human have used solar energy as energy and motion for 300 years.Modern history of solar energy from the 1615 French engineer Salomon de Cox invented the first solar-driven motives counting in the world,Plants absorb solar,Animals eat plants,Humans hunted animals,Salomon de Cox,French scientist Henri Becquerel discovered photovoltaic effectin 1893.1930 Schottky discovered photovoltaic effectof Barrier and in this year ,he maked a solar cell based on photovoltaic effect 1941 Orr discovered the photovoltaic effect in siliconIn 1954, the first monocrystalline solar cell was created and its efficiency is 6%,The advantage of Solar Energy: 1:Renewable 2:Environmental 3:Non-monopoly,Application,solar mobile phone,solar car,solar panels,Solar water heaters,Solar motor,Principle,The light that solar cells can absorb,photovoltaic effect,Utilization,In 1954, the first monocrystalline solar cell was created and its efficiency is 6%But today:Business: Polysilicon(多晶硅): 14-16% monocrystalline(单晶硅): 15-18%Civil: Si(非晶硅): 6-10%,Conversion factors 1:Light intensity 2:Material 3:Technological level,* How to improve the conversion rate of solar cells 1:Reduce losses in the light areas (Bare silicon surface reflection ratio of 36%!) Optimizing the surface to reduce reflection 2:Reduce losses in electrical terms Ideal P-N junction technology 3:New materials or technology Finding or creating materials or technology to