Lecture 3 Flashcards
is one of the oldest and largest sources of renewable energy, which uses the natural flow of moving water to generate electricity
Hydropower, or hydroelectric power,
Cost for Hydropower plant
HIGH INITIAL COST – LOW OPERATIONAL COST
most hydropower plants rely on a dam that holds back water, creating a large reservoir. Often, this reservoir is used as a recreational lake, such as Lake Roosevelt at the Grand Coulee Dam in Washington State.
Damn
gates on the dam open and gravity pulls the water through the penstock, a pipeline that leads to the turbine. Water builds up pressure as it flows through this pipe.
Intake
the water strikes and turns the large blades of a turbine, which is attached to a generator above it by way of a shaft. The most common type of turbine for hydropower plants is the Francis Turbine, which looks like a big disc with curved blades.
Turbine
FWEE
Foundation for Water & Energy Education
as the turbine blades turn, so do a series of magnets inside the generator. Giant magnets rotate past copper coils, producing alternating current (AC) by moving electrons
Generators
out of every power plant come four wires: the three phases of power being produced simultaneously plus a neutral or ground common to all three.
Power lones
used water is carried through pipelines, called tailraces, and re-enters the river downstream.
Outflow
use potential energy from dammed water. The energy extracted depends on the volume and head of the water. The difference between height of water level in the reservoir and the water outflow level is called as water head.
Conventional plants
a second reservoir is constructed near the water outflow from the turbine. When the demand of electricity is low, the water from lower reservoir is pumped into the upper (main) reservoir.
Pumped storage plant
In this type of facility, no dam is constructed and, hence, reservoir is absent. A portion of river is diverted through a penstock or canal to the turbine.
Run-of-River plant
Water from the reservoir is allowed to flow through the penstock to the turbine.
Control gate
is a huge steel pipe which carries water from the reservoir to the turbine.
Penstock
this is the most common tidal pattern, featuring two highs and two lows each day, with minimal variation in the height of successive high or low waters
Semi diurnal tide
Only a single high and a single low during each tidal day; successive high and low waters do not vary by a great deal.
Diurnal tide
characterized by wide variation in heights of successive high and low waters, and by longer tide cycles than those of the semidiurnal cycle.
Mixed tides
power can be generated only intermittently. Consists of a basin separated by dam. The flow of water between sea and basin and vice versa is through sluice. The rise and fall of tide provide the potential head. Uses reversible water turbine.
Single Basin
provide power continuously or on demand. - Consists of two basins called upper and lower basin. One basin is maintained always at a lower level than other. A dam is constructed between sea and basins as well as between basins. Powerhouse is in the dam between basins.
Double Basin
