The document summarizes pumped storage power plants, which use excess electricity at night to pump water to a higher reservoir, then release the water through turbines to generate electricity during periods of high demand. Key points include: pumped storage plants store energy by pumping water to an upper reservoir using cheap off-peak power, then releasing the water to generate peak power; they provide flexibility to power grids and improve the efficiency of thermal and nuclear base load generation; major examples from around the world include the 1,872 MW Ludington plant in the US and the 360 MW Ffestiniog plant in the UK.

1. PUMPED STORAGE PLANT
Seminar
By
Nilanjana Sen.
4th Year.
B.Power Engg.
Roll - 27

2. INTRODUCTION
Pumped Storage Power Plants are a
special type of power- plants, which
work as conventional hydropower
stations for part of the time.
When the plants are not producing
power, they can be used as pumping
stations which pump water from tail
race side to the high level reservoir.
The working of the power station
can be distinguished as the generating
phase when the turbines and generators
are electrical power and the pumping
phase when the pump and motors are
in operation.

3. HOW PUMPED STORAGE WORKS
When there's a sudden
demand for power, the
"head gates" are opened,
and water rushes down
the tunnels to drive the
turbines, which drive the
powerful generators. The
water then collects in the
bottom reservoir, ready
to be pumped back up
later.
Water is pumped up to the top reservoir at night, when demand for
power across the country is low.
Reversible turbine/generator assemblies act as pump and turbine
(usually a Francis turbine design).

4. Figure:1 Hypothetical Load Curve
LOAD CURVE FOR
PUMPED STORAGE PLANT
Figure: 2 Actual Load Curve

5. HISTORICAL DEVELOPMENT
The history of pumped storage plant can be traced as far back
as 1882, in which year the 1st hydroelectric plant making use of
pumped storage started functioning at Zurich in Switzerland.
In 1931, the 1st reversible pump-turbine was installed at
Baldeneyesee in Germany.
The 1st major reversible diagonal turbine (Deriaz) was
installed at Niagara in 1955.
In Europe, in 1962, Ffestiniog (Great Britain) with a total
capacity of 360 MW and Provindenza (Italy) with a head of
284 m, were the major landmarks in the progress of pumped
storage plants.

6. CLASSIFICATION
Both the reservoirs on a single river, in a tandem
chain manner.
Two reservoirs on two separate rivers close to each
other and flowing at different elevations.
Higher reservoir an artificially constructed pool with
the help of dykes all around, on a high level plateau
or on a leveled hill-top and the lower reservoir on a
natural river.
The lower reservoir is a natural lake while the higher
reservoir reservoir is artificial.
DAILY – daily cycle of pumping & generation
WEEKLY – weekly cycle where pumping is confined to
slack weekend periods.
SEASONAL – pumping done during lean demand &
generation during higher demand.
PURE – Closed cycle plant - - Volume of water
flowing to the lower reservoir = The water pumped
to the higher reservoir in 1 cycle of operation.
MIXED – Total generation in 1 cycle > Total
pumping during that period.
HIGH HEAD
MEDIUM HEAD
LOW HEAD – not common.
FRANCIS TURBINE – very common because of its
high efficiency and high speed.
PELTON TURBINE
KAPLAN TURBINE
HORIZANTAL – pump situated at left end & turbine
at right end; generator/motor in between -- generally
preferred due to good visibility, favorable conditions of
erections & dismantling for repairs & check-up.
VERTICAL – pump situated at lowest &
generator/motor unit at top; turbine in intermediate
position – more compact.
FOUR UNIT INSTALLATION – four different units viz.
pump, motor, generator and turbine; pump & motor coupled
together were independent of turbine & generator coupled
together.
THREE UNIT INSTALLATION – three units viz. pump,
turbine and generator which can function as a motor; pump &
turbine were coupled directly to generator/motor unit.
TWO UNIT INSTALLATION – two units viz. generator
which can operate as a motor coupled to a turbine which also
operates as a pump.

7. ADVANTAGES
Relatively low capital cost; thus economic source of
peaking capacity.
Rugged & dependable; can pick up load rapidly in a matter
of few minutes.
Readily adaptable to automation as well as remote-control.
Hydel power is free from effects of environmental
pollution—thus contributing a part in curbing air & water
pollution.

8. ADVANTAGES (contd..)
Allow great deal of flexibility in operational schedules of
system.
Power required for pumping is available at a cheaper rate(slack
hours’ rate); power produced can be sold at prime rate(peak
hours’ rate) - this compensates the low hydraulic efficiency.
They allow entire thermal or nuclear power generation to take
up base load; thus load factor improves giving overall greater
system efficiency.
Little effect on the landscape.

9. PROBLEMS OF OPERATION
Once it's used, it can't be used again until the water is
pumped back up.
Cavitation problems; powerhouse location has to be so fixed
that pump operates under submerged conditions(magnitude
depends on specific speed & net head).
Reversing of direction of flow gives rise to runner cracking
due to fatigue.
Trash racks vibrate violently during pumping operation.
Flow during pumping mode tends to lift the machine axially
causing tensile stresses in bearings; specially guide vanes.

10. TOPOGRAPHY
For an economic operation, an important criterion is the ratio of
the length, L, between the two pools along the water passage to
the head difference, h, between them, i.e
L
h
The less the value of L / h , more economic is the prospect of
the plant. Some typical ratios :
Vianden 2.9
Ludington 4.0
Horn berg 4.3

11. EFFICIENCY OF PUMPED
STORAGE PLANTS
ηo =
Now if Q is the discharge and H the gross head,
Then, Eg = ω Q (H - hf ) * 0.736 * ηt
75
And Ep = ω Q (H + hf ) * 0.736
75 ηp
Then ηo =
Ep
Eg = (H – hf ) * ηt * ηp
( H + hf )
If hf = kH, then ηo =
( 1 – k )
( 1 + k )
* ηt * ηp
ηt = Overall efficiency of
generation ;0.88
ηp = Overall efficiency of
pumping operation ;0.85
ω = speed
hf = frictional head loss
k = constant ; 0.02 – 0.03
Overall efficiency comes out to be 72 %

12. SOME FACTS
In 2000 the United States had 19.5 GW of pumped
storage capacity, accounting for 2.5% of base load
generating capacity. PHS generated (net) - 5.5 GWh of
energy because more energy is consumed in pumping
than is generated; losses occur due to water evaporation,
electric turbine/pump efficiency, and friction.
In 1999 the EU had 32 GW capacity of pumped storage
out of a total of 188 GW of hydropower and representing
5.5% of total electrical capacity in the EU.

13. PROJECT
EXAMPLES

14. 174 MW, reversible Deriaz turbines, Niagara Falls (1957).
Sir Adam Beck Hydroelectric Power Stations
Ludington
The 1872 MW plant houses six vertical Francis-type pump-
generating units which are recognized as some of the largest in
the world from the perspectives of physical size and unit rating.
Ffestiniog Pumped Storage Plant
The lower power
station has 4 water
turbines which
generate 360 MW of
electricity within 60
seconds of the need
arising

15. Some Pumped Storage Plants
Around The World

16. Australia
Bendeela (1977), 80 MW
Kangaroo Valley (1977), 160 MW
France
Grand Maison (1997), 1070 MW
Montézic (1983), 920 MW
Super Bissorte (1978), 720 MW
United States
Castaic Dam (1978), 1566 MW
Bear Swamp (1972), 600 MW
Blenheim-Gilboa (1973), 1200 MW

17. India
Bhira, Maharashtra, 150 MW
Kadamparai, Coimbatore, Tamil Nadu, 400 MW (4 x 100
MW)
Nagarjuna Sagar PH, Andhra Pradesh, 810 MW (1 x 110
MW + 7 x 100 MW)
Purulia Pumped Storage Project, Ayodhya Hills, Purulia,
West Bengal, 900 MW
Srisailam Left Bank PH, Andhra Pradesh, 900 MW (6 x
150 MW)
Tehri Dam, Uttranchal (under construction), 1000 MW

20. THANK YOU!!!