Wednesday, June 29, 2011
Pumped storage hydro power production is a means of actually saving electricity for future use. Power is generated from water falling from a higher lake to a lower lake during peak load periods. The operation is reversed during off-peak conditions by pumping the water from the lower lake back to the upper lake. A power company can obtain high-value power during peak-load generation periods by paying the lower cost to pump the water back during off-peak periods. Basically, the machine at the lower level is reversible; hence, it operates as a hydro-generator unit or a motor– pump unit.
One of the problems associated with pumped storage units is the process of getting the pumping motor started. Starting the pumping motor using the system’s power line would usually put a low-voltage sag condition on the power system. The voltage sag or dip could actually cause power quality problems.
In some cases, two turbines are used in a pumped storage installation.
One of the turbines is used as a generator to start the other turbine that is used as a pump. Once the turbine is turning, the impact on the power system is much less, and the second turbine can then be started as a motor–pump.
Above figure shows a cross-sectional view a pumped storage plant. The main access tunnel was originally used to bring all of the equipment into the powerhouse: the turbine, the pumps, and the auxiliary equipment.
Note that the Tennessee Valley Authority installed a visitor center at the top of the mountain so that the installation could be viewed by the general public.
Do you feel confused confused about this lesson? Leave your question now in a comment.
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