Pages

Tuesday, May 11, 2010

Niagra falls


Power

The enormous energy of Niagara Falls has long been recognized as a potential source of power. The first known effort to harness the waters was in 1759, when Daniel Joncaire built a small canal above the Falls to power his sawmill. Augustus and Peter Porter purchased this area and all of American Falls in 1805 from the New York state government, and enlarged the original canal to provide hydraulic power for their gristmill and tannery. In 1853, the Niagara Falls Hydraulic Power and Mining Company was chartered, which eventually constructed the canals which would be used to generate electricity. In 1881, under the leadership of Jacob Schoellkopf, Niagara River's first hydroelectric generating station was built. The water fell 86 feet (26 m) and generated direct current electricity, which ran the machinery of local mills and lit up some of the village streets.


The Niagara Falls Power Company, a descendant of Schoellkopf's firm, formed the Cataract Company headed by Edward Dean Adams,[11] with the intent of expanding Niagara Falls power capacity. In 1890, a five-member International Niagara Commission headed by Sir William Thomson among other distinguished scientists deliberated on the expansion of Niagara hydroelectric capacity based on seventeen proposals, but could not select any as the best combined project for hydraulic development and distribution. When Nikola Tesla, for whom a memorial was later built at Niagara Falls, NY (USA), invented the three-phasesystem of alternating current power transmission, distant transfer of electricity became possible, as Westinghouse and Tesla had built the AC-power Ames Hydroelectric Generating Plant and proved it effective. In 1893, Westinghouse Electric was hired to design a system to generate alternating current on Niagara Falls, and three years after that, the world's first large AC power system was created, activated on August 26, 1895. The Adams Power Plant Transformer House remains as a landmark of the original system.

By 1896, with financing from moguls like J.P. MorganJohn Jacob Astor IV, and theVanderbilts, they had constructed giant underground conduits leading to turbines generating upwards of 100,000 horsepower (75 MW), and were sending power as far as Buffalo, 20 miles (32 km) away. Some of the original designs for the power transmission plants were created by the Swiss firm Faesch & Piccard, which also constructed the original 5,000HP waterwheels.

Private companies on the Canadian side also began to harness the energy of the Falls. The Government of the province of Ontario, Canada eventually brought power transmission operations under public control in 1906, distributing Niagara's energy to various parts of the Canadian province.

Other hydropower plants were also being built along the Niagara River. But in 1956, disaster struck when the region's largest hydropower station was partially destroyed in a landslide. The landslide drastically reduced power production and tens of thousands of manufacturing jobs were at stake. In 1957, Congress passed the Niagara Redevelopment Act, which granted the New York Power Authority the right to fully develop the United States' share of the Niagara River's hydroelectric potential.[12]

In 1961, when the Niagara Falls hydroelectric project first went on line, it was the largest hydropower facility in the Western world. Today, Niagara is still the largest electricity producer in New York State, with a generating capacity of 2.4 gigawatts (million kilowatts). Up to 375,000 US gallons (1,420 m3) of water a second is diverted from the Niagara River through conduits under the City of Niagara Falls to theLewiston and Robert Moses power plants. Currently between 50% and 75% of the Niagara River's flow is diverted via four huge tunnels that arise far upstream from the waterfalls. The water then passes through hydroelectric turbines that supply power to nearby areas of the Canada and the USA before returning to the river well past the Falls.[13] This water spins turbines that power generators, converting mechanical energy intoelectrical energy. When electricity demand is low, the Lewiston units can operate as pumps, to transporting water from the lower bay back up to the plant's reservoir allowing this water to be used again during the daytime, when electricity use peaks. During peak electrical demand, the same Lewiston pumps are reversed and actually become generators, similar to those at the Moses plant.[12]

During tourist season, water usage by the power plant is limited by a treaty signed by the U.S. and Canada in 1950 in order to preserve this natural attraction. On average the Niagara river contains 1,500,000 US gallons (5,700 m3) of water per second, half of which must flow over the falls during daylight hours from April through October. During other times the power plant may use up to three fourths of the total available water. During winter the Power Authority of New York works with Ontario Power Generation, to prevent ice on the Niagara River from interfering with power production and causing the flooding of shoreline property. One of their joint efforts is an 8,800-foot (2,700 m)–long ice boom, which prevents the buildup of ice, yet allows water to continue flowing downstream.[12]

The most powerful hydroelectric stations on the Niagara River are Sir Adam Beck 1 and 2 on the Canadian side, and the Robert Moses Niagara Power Plant and the Lewiston Pump Generating Plant on the American side. All together, Niagara's generating stations can produce about 4.4GW of power.

In August 2005 Ontario Power Generation, which is responsible for the Sir Adam Beck stations, announced plans to build a new 6.5 miles (10.5 km) tunnel to tap water from farther up the Niagara river than is possible with the existing arrangement. The project is expected to be completed in 2009, and will increase Sir Adam Beck's output by about 182 MW (4.2%).

No comments:

Post a Comment