复旦大学：《能源与环境 Energy and the Environment》教学课件_5_Energy and the environment V

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

Direct uses of solar radiation Indirect less direct uses of solar radiation Hydroelectricity Wind 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

Solar radiation 174,000×1012W Short-wave Tidal diation adiation Direct reflection 52,000×1012W(30%) Tides, tidal currents, etc. 3×1012W Direct conversion to heat 82,000×1012W(47% Evaporation, precipitation, etc Storage 40,000×1012w(23% water anc ice Convection Volcanoes and hot springs 0.3×1012w Winds, 370×102W Decay Photosynthesis Storage Conduction Animals 40×1012W in plants 32×1012W Terrestrial Earh 00400310108818311 Fossil fuels Nuclear therma Figure5. 1 Natural energy flow (in units of power) to and from the earth. Source: M. K Hubbert, Mans Conquest of Energy: Its Ecological and Human Consequences, in The environmental and Ecological Forum 1971-1972. Washington D. C: U.S. Atomic Energy Commission Publication TID-25857, 1972.) 复旦大学环境科学与工程系 Department of Environmental Science and Engineering, Fudan University

Figure5.1 Natural energy flow(in units of power) to and from the earth. (Source:M.K. Hubbert, “Man’s Conquest of Energy: Its Ecological and Human Consequences,” in The Environmental and Ecological Forum 1971-1972. Washington D.C.: U.S. Atomic Energy Commission Publication TID-25857, 1972.)

Hydropower It dates back to the beginnings of the electric power industry more than 100 years ago In us about 7% of the electric power now generated comes from damming the rivers as they flow to the ocean and then releasing the water to turn turbines connected to electric generators In other countries electricity from water power Norway 99% Nepal 95% Brazil 93% New zealand 78% Canada 58% Sweden 50% 复旦大学环境科学与工程系 Department of Environmental Science and Engineering, Fudan University

It dates back to the beginnings of the electric power industry more than 100 years ago. In US.: About 7% of the electric power now generated comes from damming the rivers as they flow to the ocean and then releasing the water to turn turbines connected to electric generators. Hydropower In other countries: electricity from water power Norway 99% Nepal 95% Brazil 93% New Zealand 78% Canada 58% Sweden 50%

Hydropower was important long before electricity generation possible Moving water acting on a waterwheel can be used to ease human labor was found about 2000 years ago Waterwheel Grinding grain mechanisms Sawing wood 13th century to operate hammers in ironworks of western Europe 1 6th century, the primary source of industrial power Finally it was replaced by steam engine in many application Now, we use water power almost exclusively for the generation of electricity 复旦大学环境科学与工程系 Department of Environmental Science and Engineering, Fudan University

Hydropower was important long before electricity generation possible Moving water acting on a waterwheel can be used to ease human labor was found about 2000 years ago. Waterwheel mechanisms Grinding grain Sawing wood 13th century, to operate hammers in ironworks of western Europe 16th century, the primary source of industrial power Finally it was replaced by steam engine in many application. Now, we use water power almost exclusively for the generation of electricity

Hydropower a consequence of the natural cyclical transport of water between the earth's surface and the atmosphere Heated by sunlight, followed by precipitation and the downward course of the water in rivers and streams under the force of gravity In a sense the water is the working fluid in an enormous heat engine powered by sunlight 2 E= mgh Modern hydroelectric installations convert the potential energy of water to electric energy at an efficiency of 80 to 90% 复旦大学环境科学与工程系 Department of Environmental Science and Engineering, Fudan University

Hydropower A consequence of the natural cyclical transport of water between the earth’s surface and the atmosphere. Heated by sunlight, followed by precipitation and the downward course of the water in rivers and streams under the force of gravity. In a sense the water is the working fluid in an enormous heat engine powered by sunlight. E= mg∆h = Modern hydroelectric installations convert the potential energy of water to electric energy at an efficiency of 80 to 90%. 2 2 1 mv

Hydropower Condensation m Condensation and deposition and deposition niin 1111 thn Ice-\'Precipitation Evaporation A pRecipitation 二 Hydroelectric plant Evaporation …,…,mman: ∴…‘",,,," Underground,… Ocean ∴3. Figure 5.2 The hydrologic cycle. Electricity is produced in the hydroelectric plant by the action of water against a turbine connected to a generator. In this way the stored potential energy of the water in the reservoir becomes electrical energy 复旦大学环境科学与工程系 Department of Environmental Science and Engineering, Fudan University

Hydropower Figure 5.2 The hydrologic cycle. Electricity is produced in the hydroelectric plant by the action of water against a turbine connected to a generator. In this way the stored potential energy of the water in the reservoir becomes electrical energy

eg. Calculate the flow rate of water(in liters/sec=kilograms/sec)required to provide lkw of electric power if the water falls a vertical distance of 90m Assume 80% conversion efficiency. (1.42liters/sec) 复旦大学环境科学与工程系 Department of Environmental Science and Engineering, Fudan University

eg. Calculate the flow rate of water (in liters/sec = kilograms/sec) required to provide 1kW of electric power if the water falls a vertical distance of 90m. Assume 80% conversion efficiency. (1.42liters/sec)

Advantages No polluting emissions into the air or water No waste heat is rejected as thermal pollution Lifetimes of many decades small maintenance requirements Respond well to sudden changes in demand, making hydroelectricity well suited to matching peak loads The dams can serve multiple purposes Water stored for irrigation flood control municipal drinking water supply, power a hydroelectric plant 复旦大学环境科学与工程系 Department of Environmental Science and Engineering, Fudan University

Advantages: No polluting emissions into the air or water No waste heat is rejected as thermal pollution Lifetimes of many decades small maintenance requirements. Respond well to sudden changes in demand, making hydroelectricity well suited to matching peak loads. The dams can serve multiple purposes; Water stored for irrigation, flood control, municipal drinking water supply, power a hydroelectric plant

In the late 1980s Boulder. 6MW.8% of electricity power used in the city The payback time for this system is 10 ears,the city is making a pI investment. Through sales of electricity to the electric utility Xcel Energy, this hydroelectric system earned revenue of $1. 7 million for the city in 2004 Figure 5.3 Hoover Dam and lake mead on the Colorado river at the arizona-Nevada border. This installation produces 2080 MW of electrical power as well as storing water for other purposes, including flood protection, irrigation, and recreation (source: Courtesy Bureau of Reclamation/ U.S. Department of Energy) 复旦大学环境科学与工程系 Department of Environmental Science and Engineering, Fudan University

Figure 5.3 Hoover Dam and Lake Mead on the Colorado River at the Arizona-Nevada border. This installation produces 2080 MW of electrical power as well as storing water for other purposes, including flood protection, irrigation, and recreation. (source: Courtesy Bureau of Reclamation/ U.S. Department of Energy) In the late 1980s, Boulder. 6MW, 8% of electricity power used in the city The payback time for this system is 10 years, the city is making a profit on its investment. Through sales of electricity to the electric utility Xcel Energy, this hydroelectric system earned revenue of $1.7 million for the city in 2004