Energy Power and Climate Change 8 8 Wave
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Energy, Power, and Climate Change 8. 8 Wave Power WAVES Common water waves are produced by the sun-driven winds passing over the water's surface. The height of the waves depends on the following three factors: The speed of the wind The duration of the wind The fetch
FYI: The FETCH is the. Power, length of the water. Climate over which the. Change wind passes. Energy, and FYI: A NNE wind on Lake Michigan produces a much larger amplitude. . . 8. 8 Wave Power than a west wind. FETCH FYI: The course of the Edmund Fitzgerald on Lake Superior.
Energy, Power, and Climate Change 8. 8 Wave Power POWER IN A WATER WAVE A L The power of a water wave is complicated to calculate, so we'll simplify it some. Think of the crest as storage of potential energy, and the falling water as conversion into kinetic energy.
FYI: The AVERAGE HEIGHT of the water. Climate is A / 2. Energy, Power, and Change FYI: This much potential 8. 8 energy. Wave is converted into kinetic energy each Power period T. POWER IN A WATER WAVE FYI: Power is energy per time: U = mgh FYI: Power is proportional to the SQUARE of the AMPLITUDE A. U = mg. A/2 Power is proportional to the WAVE SPEED V. Power is porportional to the LENGTH of the WAVEFRONT U L. = Vg. A/2 U = LAg. A/2 A A/2 L U = Lg. A 2/2 = VT K = Lg. A 2/2 K = VTLg. A 2/2 P = g. VLA 2 2 Power Generated By A Wave
3. FYI: The mass density. Power, of water is 1000 Energy, andkg/m Climate Change 8. 8 Wave Power POWER IN A WATER WAVE Waves having an amplitude of 2 m roll onto a beach at a rate of one every 8 seconds. The wave crests are 75 meters apart. (a) What is the wave velocity? V = d/t = /T = 75/8 = 9. 75 m/s (b) How much wave power is there, per unit length? P = g. VLA 2 2 g. VA (1000)(10)(9. 75)2 P / L = = 195 k. W/m = 2 2 (c) How much wave power is there along 25 km of beach? P = (195 k. W/m)L P = (195 k. W/m)(25000 m) P = 4875 MW
Energy, Power, and Climate Change 8. 8 Wave Power POWER GENERATION FROM A WATER WAVE THE OSCILLATING WATER COLUMN Air Column - Compressed and rarefied by rising and falling wave. Wind Turbine Generator Turbine generates both ways
FYI: A pelamis can generate 750 k. W of power. Energy, Power, and Climate Change 8. 8 Wave Power POWER GENERATION FROM A WATER WAVE THE PELAMIS The pelamis is named after the sea snake for obvious reasons. Each of four sections is hinged to the previous one. Fluid inside moves back and forth. The moving fluid drives a generator.