Energy and the Environment CHEN HONG E-mail:chong@fudan.edu.cn Phone:021-65642526 复旦大学环境科学与工程系 Department of Environmental Science and Engineering, Fudan University
Energy and the Environment CHEN HONG E-mail: chong@fudan.edu.cn Phone: 021-65642526
Breaking our dependence on the limited fossil fuel resources Renewable energy source Substantial environmental Reasons 复旦大学环境科学与工程系 Department of Environmental Science and Engineering, Fudan University
Breaking our dependence on the limited fossil fuel resources Substantial environmental Reasons Renewable energy source
Renewable and Nonrenewable Energy Sources All the fossil fuels(coal, oil, natural gas, shale oil, tar sands, etc. ) Uranium-235 nuclear fission fuel, deuterium nuclear fusion fuel, and some other types of geothermal energy The time to exhaust a nonrenewable resource depends on the rate of use and size of the resource It is likely that most forms of nonrenewable energy will get more expensive when they are near exhaustion We have only three sources of renewable energy: Solar, geothermal, and tidal All energy sources based on the solar energy incident on earth-direct sunlight wind, hydroelectric power, ocean currents, ocean thermal gradients, and biomass are renewable The energy in the oceans tides has its origin in the gravitational interaction between the earth and the moon and to a lesser extent between the earth and the sun The more renewable energy we use, the cheaper it will be 复旦大学环境科学与工程系 Department of Environmental Science and Engineering, Fudan University
Renewable and Nonrenewable Energy Sources All the fossil fuels(coal, oil, natural gas, shale oil, tar sands, etc.), Uranium-235 nuclear fission fuel, deuterium nuclear fusion fuel, and some other types of geothermal energy. The time to exhaust a nonrenewable resource depends on the rate of use and size of the resource. It is likely that most forms of nonrenewable energy will get more expensive when they are near exhaustion. We have only three sources of renewable energy: Solar, geothermal, and tidal. All energy sources based on the solar energy incident on earth – direct sunlight, wind, hydroelectric power, ocean currents, ocean thermal gradients, and biomass, are renewable. The energy in the oceans’ tides has its origin in the gravitational interaction between the earth and the moon, and to a lesser extent, between the earth and the sun. The more renewable energy we use, the cheaper it will be
Direct uses of solar radiation Indirect/Less direct uses of solar radiation Hydroelectric W Ind energy Biomass Renewable Ocean thermal gradients Energy Ocean currents Ocean waves Ocean tides Geothermal resources 复旦大学环境科学与工程系 Department of Environmental Science and Engineering, Fudan University
Direct uses of solar radiation Indirect/Less direct uses of solar radiation Hydroelectricity Wind energy Biomass Ocean thermal gradients Ocean currents Ocean waves Ocean tides Geothermal resources Renewable Energy
Energy consumption in 2003 in U.S. Table 1.1 U.S. Energy Consumption in 2003 Source Amount OBtm Percent I QBtu Equiv Coal 1.08×10 9 tons 22.6 23.0 47.8×10°tons Natural gas 218×1012t3 22.5 22.9 097×1012ft Petroleum 6.72×10bbl 39.1 398 172×10bbl N uclear elcc 757×10°kWh 797 8.1 95×10kWh Renewables 578×10kWh 6.15 6.3 94×10kWh Total 98.3 复旦大学环境科学与工程系 Department of Environmental Science and Engineering, Fudan University
Energy consumption in 2003 in U.S
Energy consumption of renewable energy Energy Source BTu Percent Conventional hydroelectric power 2.779 2.83 Geothermal energy 0.314 0.32 Bi lomas 2.884 2.94 Solar energy 0.063 0.06 Wind 0.108 0.11 Total 6.15 6.3 Hydroelectricity generated by pumped storage is not included in renewable energy bBased on total energy consumption of 98. 156 QBtu in 2003 (Source: U.S. Energy Information Administration, Annual Energy Review, 2003. 复旦大学环境科学与工程系 Department of Environmental Science and Engineering, Fudan University
Energy consumption of renewable energy
Solar energy Northern spring/ Northern winter/ Southern fall 21 March Southern summer Periapsis Line of Solstice 21 June 21. Decemb Apoapsis 3. July 23 September Northern summer/ Northern fall/ Southern winter Southern spring The earth, at 93 X106 miles(1.49 X 10 meters) from the sun, makes a complete revolution about the sun once per year Itself rotates on its north-south axis once every 24 hours 23.5 degrees from the perpendicular to the plane of its orbit about the sun 复旦大学环境科学与工程系 Department of Environmental Science and Engineering, Fudan University
The earth, at 93×106 miles (1.49×1011 meters) from the sun, makes a complete revolution about the sun once per year. Itself rotates on its north-south axis once every 24 hours. 23.5 degrees from the perpendicular to the plane of its orbit about the sun. Solar Energy
Solar Energy D.25 Infrared f 2: wave length f: frequency, o.15 C: the speed of light 3X108m/s Solar constant o.10 2 cal/min cm The power density at the top of the atmosphere 4 is available at ground level Figure 4.1 The wavelength distribution of solar radiation above the atmosphere( dashed line) and at the earths surface(solid line). The solar Constant is given by the area under the dashed curve. The sharp dips in the solid line are due to absorption of certain wavelengths by various atmospheric gases, including water vapor and carbon dioxide (Adapted from On the Nature and Distribution of solar Radiation, Watt Engineering, Washington, D. C U.S. Government Printing Office, Department of Energy HCP/T2552-01, 1978) 复旦大学环境科学与工程系 Department of Environmental Science and Engineering, Fudan University
Figure 4.1 The wavelength distribution of solar radiation above the atmosphere(dashed line) and at the earth’s surface(solid line). The solar Constant is given by the area under the dashed curve. The sharp dips in the solid line are due to absorption of certain wavelengths by various atmospheric gases, including water vapor and carbon dioxide. (Adapted from On the Nature and Distribution of Solar Radiation, Watt Engineering, Washington, D.C.: U.S. Government Printing Office, Department of Energy HCP/T2552-01, 1978) Solar Energy λ = f c λ: wave length, f: frequency, c: the speed of light 3x108 m/s Solar Constant: 2 cal/min·cm2 The power density at the top of the atmosphere ¼ is available at ground level
Soiar as at' ident or atmosphere 00% Up-scatt From clouds Up-scatter I A: mospheric from atmosphere absorption I Absorp:ICn Down-scatter 13 from atmosphere Direct solar 6% 24 DIffuse dowr-sca*ter from clouds 17 Ground Absorption and scattering of solar radiation in the atmosphere. The values shown are average weather and are averaged over all seasons and latitudes On average, we see that 47%(17%0+24%+6%)of the solar power incident on the upper atmosphere reaches the ground and can be utilized in some fashion 复旦大学环境科学与工程系 Department of Environmental Science and Engineering, Fudan University
Absorption and scattering of solar radiation in the atmosphere. The values shown are average weather, and are averaged over all seasons and latitudes. On average, we see that 47% (17%+24%+6%) of the solar power incident on the upper atmosphere reaches the ground and can be utilized in some fashion
We can get the average on the horizontal area 12 cal/min cm2*47%=164 W/m2 This is the average value for a 24 hour day The average for an 8-hour day centered about noon is much larger. An optimistic but still reasonable estimate could be about 600W/m2 which is about 1520 Btw/ft2 Let's estimate the gross amount of solar energy incident on the US in a year. (The area of US is 3.615X 106 mile 2) The total is 5.6X1019 Btu/year. which is about 600 times the total energy consumed in US in1996(938X10 Btu) 复旦大学环境科学与工程系 Department of Environmental Science and Engineering, Fudan University
We can get the average on the horizontal area : ½ cal/min∙cm2 * 47% = 164 W/m2 This is the average value for a 24 hour day. The average for an 8-hour day centered about noon is much larger. An optimistic, but still reasonable, estimate could be about 600W/m2, which is about 1520 Btu/ft2. Let’s estimate the gross amount of solar energy incident on the US in a year. (The area of US is 3.615×106 mile2) The total is 5.6×1019 Btu/year, which is about 600 times the total energy consumed in US in1996 (93.8×1015 Btu)
