“ Hydroelectric power ” Under the guidance of Prof. P. V. Kulkarni By DESHMUKH OM CHILLE SWAPNIL PATIL VIJAY TARAL TUSHAR.

“Hydroelectric power”

Under the guidance of

Prof. P. V. Kulkarni

By•DESHMUKH OM•CHILLE SWAPNIL •PATIL VIJAY •TARAL TUSHAR

it is important to note that when determining head, hydrologists take into account the pressure behind the water. water behind the dam puts pressure on the falling water.

How a Hydroelectric Power System Works

Flowing water is directed at a turbine (remember turbines are just advanced waterwheels). The flowing water causes the turbine to rotate, converting the water’s kinetic energy into mechanical energyIt is the most widely used form of renewable energy, accounting for 16 percent of global electricity consumption.

THE MECHANICAL ENERGY PRODUCE BY TURBINE IS CONVERTEDINTO ELECTRICAL ENERGY.

When more water flows through a turbine, more electricity can be produced.The flow rate depends on the size of the river and the amount of water flowing in it. Power production is considered to be directly proportional to river flow. That is, twice as much water flowing will produce twice as much electricity.

Flow Rate = the quantity of water flowing

The further the water falls, the more power it has. The higher the dam, the farther the water falls, producing more hydroelectric power.Power production is also directly proportional to head. That is, water falling twice as far will produce twice as much electricity.

Head = the height from which water falls

1) Conventional (dams)- Most hydroelectric power comes from the potential energy of dammed water driving a water turbine and generator. The power extracted from the water depends on the volume and on the difference in height between the source and the water's outflow. This height difference is called the head.

GENERATING METHODS

2) Pumped-storage-This method produces electricity to supply high peak demands by moving water between reservoirs at different elevations. At times of low electrical demand, excess generation capacity is used to pump water into the higher reservoir.

3) Run-of-the-river-Run-of-the-river hydroelectric stations are those with small or no reservoir capacity, so that the water coming from upstream must be used for generation at that moment, or must be allowed to bypass the dam.

Hydroelectric power plants do not use up limited nonrenewable resources to make electricity. They do not cause pollution of air, land, or waterThey have low failure rates, low operating costs, and are reliable. The longer we delay the balanced development of our potential for hydropower, the more we unnecessarily use up other vital resources.n provide startup power in the event of a system wide power failure.

HYDROPOWER, THE ENVIRONMENT, AND SOCIETY

ADVANTAGES

1) Flexibility-Hydro is a flexible source of electricity since plants can be ramped

up and down very quickly to adapt to changing energy demands.

2) Low power costs- The major advantage of hydroelectricity is elimination of the cost of fuel.

3) Reduced CO2 emissions- Since hydroelectric dams do not burn fossil fuels, they do not directly produce carbon dioxide. While some carbon dioxide is produced during manufacture and construction of the project, this is a tiny fraction

DISADVATAGES1) Ecosystem damage and loss of land Large reservoirs required for the operation of hydroelectric power stations result in submersion of extensive areas upstream of the dams, destroying biologically rich and productive lowland and riverside valley forests, marshland and grasslands.

2) Siltation and flow shortageWhen water flows it has the ability to transport particles heavier than itself downstream. This has a negative effect on dams and subsequently their power stations,particularly those on rivers or within catchment areas with high siltation.

3) RelocationAnother disadvantage of hydroelectric dams is the need to relocate the people living where the reservoirs are planned.

TYPES OF HYDROPOWER

A large hydropower facility has the capacity to produce more than 30,000 kilowatts (kW) of electricity.

The majority of hydropower systems in the U.S. fit in this category.

Large hydropower systems typically require a dam.

1) LARGE HYDROPOWER

Small hydropower facilities can produce 100 – 30,000 kilowatts (kW) of electricity.

Small hydropower facilities may involve a small dam, or be a diversion of the main stream, or be a run-of-the-river system.

2) SMALL HYDROPOWER

Micro hydropower plants have the capacity to produce 100 kilowatts (kW) or less.

Micro-hydro facilities typically use a run-of-the-river system.

3) Micro Hydropower

A simple formula for approximating electric power production at a hydroelectric plant is:

P=ρhrgk, Where

P is Power in watts,

ρ is the density of water (~1000 kg/m3),

H is height in meters,

r is flow rate in cubic meters per second,

g is acceleration due to gravity of 9.8 m/s2,

K is a coefficient of efficiency ranging from 0 to 1.

CALCULATION

Efficiency is often higher (that is, closer to 1) with larger and more modern turbines. Annual electric energy production depends on the available water supply.

Ten of the largest hydroelectric producers as at 2009.

CountryAnnual hydroelectricproduction (TWh)

Installedcapacity (GW)

Capacityfactor

 % of totalcapacity

 China 652.05 196.79 0.37 22.25

 Canada 369.5 88.974 0.59 61.12

 Brazil 363.8 69.080 0.56 85.56

 United States 250.6 79.511 0.42 5.74

 Russia 167.0 45.000 0.42 17.64

 Norway 140.5 27.528 0.49 98.25

 India 115.6 33.600 0.43 15.80

 Venezuela 85.96 14.622 0.67 69.20

 Japan 69.2 27.229 0.37 7.21

 Sweden 65.5 16.209 0.4644.34

CONCLUSION

Hydropower is important from an operational standpoint as it needs no "ramp-up" time, as many combustion technologies do. Hydropower can increase or decrease the amount of power it is supplying to the system almost instantly to meet shifting demand. With this important load-following capability, peaking capacity and voltage stability attributes, hydropower plays a significant part in ensuring reliable electricity service and in meeting customer needs in a market driven industry. In addition, hydroelectric pumped storage facilities are the only significant way currently available to store electricity.

REFERENCES

•http://ga.water.usgs.gov/edu/hyhowworks.html•http://en.wikipedia.org/wiki/Hydroelectricity•Reclamation Managing Water in the West, Hydroelectric Power, U. S. Department of the interior Bureau of Reclamation Power Resource Office, July 2005.•www.howtopowertheworld.com/advantages-of-hydroelectric-energy•www.conserve-energy-future.com/Disadvantages_HydroPower.php

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