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Wave motors were machines designed and built in the late 19th and early 20th century to harness the power of wave or tidal energy. Many experiments were planned or built in California employing various methods. However, the earliest wave motors were not intended for the creation of electricity. Prior to 1880, wave motors were designed to operate non-electrically to power vehicles, mills, flush sewers, clean streets and conserve fresh water. Power in the ocean is enormous, yet it is still the greatest untapped resource for generated electricity today. The challenge with wave generators has always been how to harness such great power. The cost to maintain an ocean wave generator is excessive and often leads to eventual failure. Materials that have also been used in the past to capture sea movements deteriorate quickly. Additionally, early prototypes of wave generators would accumulate damage from animals, plants, and bad weather conditions which interrupt or damage the inner workings of early models. Some wave motors work with the installation consisting of two shafts drilled 30 feet into a cliff, one is 8 feet in diameter and the other one is 5 feet in diameter. In one of the shafts there is a heavy float that drives a piston within a pump in the other shaft. As the wave enters the float in the shaft and the pump in the landward shaft both rise. The float and piston are connected by a cable to a bar, similar to a lever. The rising float causes the lever to pull up the one way piston pump and squeeze up into the discharge pipe. As the water leaves the system, the heavy float drops and checks valves in the piston and the pump stopped backward flow of water. This cycle repeats with more waves. The first wave motor was created by a man named E. Stern. The wave motor was built in California located near the Cliff House in San Francisco. On the evening of January 16, 1887 the schooner Parallel drifted past Stern's wave motor and became lodged on the rocks of the big bluff nearby. Adolph Sutro and other locals went down to the beach to aid the ship. Finding no one aboard, they adjourned until morning. The Parallel, loaded with 40 tons of dynamite and other highly flammable materials, had been on her way to Oregon when she ran into the rocks near the entrance of the Golden Gate. Her crew had wasted no time in abandoning her. At 12:34 a.m., the Parallel's cargo exploded with such force that it was felt as far away as Sacramento and San Jose. Stern's wave motor was only a short distance away. It was badly damaged by the blast and its plight was mentioned in the local papers. The explosion also damaged the Cliff House but it was quickly remodeled. In the end, Mr. Stern must have given up on his wave motor. What exactly happened to it is unknown. It was completely gone by August 1891 when a new wave motor was erected in the same area. How was Mr. Stern's wave motor supposed to work? The few descriptions of this machine that are known at this time do not give a very good idea of the mechanics. Years later The Examiner described it thus, "That (machine) operated in a wiggle-waggle sort of way depending on the pushing power of the waves against a broad surface, something like the centerboard of a flat-bottomed vessel." 1 The second wave motor was constructed by a man named Henry P. Holland in 1891 on a very large rock also near the Cliff House. The only records of this machine are preserved in photographs and stereo views. This wave motor was funded by a mining man known as J.A. Fischer who wanted to keep the production of the wave motor a secret until it was actually a success and went to great lengths to make sure that no one saw it while it was still being built. This particular wave motor worked by moving a 3000-pound iron buoy up and down through the motion of the waves which activated a pump. The pump was expected to work at eight strokes per minute, which would raise the water up through a pipe on the side of one of the cliffs. From there, the water would run back down through a series of water wheel motors that would generate electricity which Holland and Fischer hoped to sell to manufacturers. It was said that this was the first wave motor built in California for commercial purposes but that point cannot be proved because it is unclear whether the wave motor was ever completed. This wave motor was very well built and it managed to stay attached to the rock it was built on for 59 years until in 1950 when it was finally blown off of the rock by a storm.〔Miller, Christine. (2003 October 4) ''Wave Motors and Tide Machines at the Cliff House: 1886 to present''. http://outsidelands.org/wave-motor.php〕 Ocean wave generators and technology have advanced a long way since then. There have been at least three known successful models of wave generators. These models are known as the “Pelamis”, “Limpet”, and “Anaconda”. Ocean Power Delivery developed Pelamis, a long hinged tube, which uses the motion of the water to bend hinges which activate hydraulic pumps that drive generators. “Limpet”, or Land Installed Marine Power Energy Transformer, is located near Scotland. The waves enter the shell chamber which raise and lower the air pressure inside the chamber which, in turn, causes the Wells Turbine to move. The “Anaconda” wave generator rides the waves, similar to the Pelamis, but uses the motion to operate a turbine in its tail. The advancement of technology has allowed scientists to move towards a workable solution for our energy needs. Ocean wave generators may be more than just prototypes sometime in the near future.〔http://science.howstuffworks.com/environmental〕 〔.〕〔"Utilizing the Tide: A New and Practical Wave Motor", Argonaut, June 2, 1877, p. 7.〕 ==References== 〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Wave motor」の詳細全文を読む スポンサード リンク
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