Rather than having the water flow stopped by hitting the center of the cup on a standard wheel and wasting the kinetic energy, the water flow was split and deflected left and right into the dual buckets. Pelton commented that "my invention relates to certain improvements in water wheels of that class which are driven by the momentum of a stream of water delivered into buckets on the periphery of a wheel through a suitable discharge nozzle and under a high pressure.
The stream of water is divided into two parts by a central ride which directs the current of water into the curved bottoms of the two halves of the bucket, from which it passes out over the flaring or divergent sides of the bucket, so as to escape smoothly and utilize the full reactionary force of the escaping stream, in addition to the direct force of the impinging jet.
This unique design revolutionized the use of turbines in high-energy sites, such as small, fast-running mountain streams. This was made possible because Pelton's wheel was driven by the kinetic energy of the water jet, rather than the pressure of the water hitting the cup harder to accomplish efficiently in narrow, low-volume waterways. In the late s Pelton successfully modeled, tested, and manufactured his first turbine wheel.
In , a foot-diameter wheel was installed at a gold mine in Grass Valley, CA. Pelton's invention transformed the American West by replacing expensive, bulky steam engines at mining and construction sites with low-cost hydroelectric power.
By the turn of the century the age of hydroelectric power was flourishing. Twenty years after forming Pelton Water Wheel Company in San Francisco to meet the growing demand for hydropower and hydroelectricity, Pelton died in at age He tested his designs in and , getting a patent in In , the Pelton turbine won a competition for the most efficient water wheel turbine held by the Idaho Mining Company of Grass Valley, California.
The Pelton water wheel turbine set the standard until the Turgo impulse wheel was invented by Eric Crewdson in However, the Turgo impulse wheel was an improved design based on the Pelton turbine.
The Turgo was smaller than the Pelton and cheaper to manufacture. Two other important hydropower systems include the Tyson turbine, and the Banki turbine also called the Michell turbine. Pelton wheels were used to provide electrical power at hydroelectric facilities around the world. One in Nevada City had an output of horsepowers of electricity for 60 years. The largest units can produce over megawatts.
Hydropower converts the energy of flowing water into electricity or hydroelectricity. The amount of electricity generated is determined by the volume of water and the amount of "head" the height from the turbines in the powerplant to the water surface created by the dam. The greater the flow and head, the more electricity is produced. The mechanical power of falling water is an age-old tool. Of all the renewable energy sources that generate electricity, hydropower is the most often used.
It is one of the oldest sources of energy and was used thousands of years ago to turn a paddle wheel for purposes such as grinding grain. In the s, mechanical hydropower was used extensively for milling and pumping. The first industrial use of hydropower to generate electricity occurred in , when 16 brush-arc lamps were powered using a water turbine at the Wolverine Chair Factory in Grand Rapids, Michigan. The first U. Until that time, coal was the only fuel used to produce electricity.
The early hydroelectric plants were direct current stations built to power arc and incandescent lighting during the period from about to Because the source of hydropower is water, hydroelectric power plants must be located on a water source. By the early s, hydroelectric power accounted for more than 40 percent of the United States' supply of electricity.
The years through saw rapid changes occur in hydroelectric design and a wide variety of plant styles built. At first he went to Sacramento and became a fisherman. He was not successful at fishing so he decided to move. In all types of mining were going on: placer, hardrock, and hydraulic. Pelton did not want to be a miner so he decided to improve mining methods. He watched, studied, and learned about methods needed to power hydraulic mining.
Hardrock mines also needed power to lower the men into the mines, bring up the ore cars, and return the workers to the surface at the end of their shift. Power was also needed to operate rock crushers, stamp mills, pumps, and machinery. At the time the steam engine was used by many mines for their main power source, but the hillsides were running out of wood and trees.
The Empire Mine in Grass Valley used about twenty cords of wood a day. Pelton knew the forests were disappearing so he began thinking about inventing a water wheel. In he experimented with several types of wheels.
According to a article by W. Durand of Stanford University in Mechanical Engineering, "Pelton's invention started from an accidental observation, some time in the s. Pelton was watching a spinning water turbine when the key holding its wheel onto its shaft slipped, causing it to become misaligned.
Instead of the jet hitting the cups in their middle, the slippage made it hit near the edge; rather than the water flow being stopped, it was now deflected into a half-circle, coming out again with reversed direction.
Surprisingly, the turbine now moved faster. That was Pelton's great discovery.
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