This presentation includes introduction to run off river (ROR) plant and pumped storage plants, comparison between traditional and run off river plant, Classification of ROR Plants, Advantages and disadvantages of ROR Plants, Introduction to Pumped Storage Power (PSP) Plants, Classification of PSP, and Advantages and disadvantages of PSP

1. Run of River and Pumped Storage
Plants
Prepared by
Prof. S. G. Taji
Dept. of Civil Engineering
S.R.E.S’s Sanjivani College of Engineering,
Kopargaon

2. Run of River Power Plants
Prepared by: Prof. Taji S. G.
2
 Run of River power plants do not have large reservoirs
to store water. Because they can't store water and
usually generate much less power than hydroelectric
dams.
 In run of river systems, running water is diverted from
a flowing river and guided down a channel, or
penstock, which leads to a generating house.
 There the force of the moving water spins a turbine and
drives a generator.

3. Prepared by: Prof. Taji S. G.
3

4. Run of River Power Plants
Prepared by: Prof. Taji S. G.
4
 For a run-of-river system to operate, two geographical
features are required:
 One is a substantial flow of water, originating either
from rainfall or snowpack melting.
 The other is sufficient hydrostatic head to enhance
the water’s energy.
 A greater drop in elevation means more gravitational
force acts upon the water, increasing its kinetic energy.
 It is important that the river have large and constant
year-round flow as well.

5. Comparison between traditional and
Run of River (ROR) Plant
Prepared by: Prof. Taji S. G.
5
 In conventional storage hydro, a dam is placed
across a river to create a reservoir.
 All (or almost all) of the water is impounded behind
the dam and the flow downstream is regulated, which
changes the natural variation of flow significantly for
the entire length of the downstream river.
 With ROR hydro, only a portion of the stream
flow is affected, and even then, only a short
length of the river experiences reduced flows.
 a typical power plant would utilize less than two-
thirds of a river’s total annual flow.

6. Classification of ROR Plants
Prepared by: Prof. Taji S. G.
6
 Run-off river plants without pondage:
 These plants does not have storage or pondages to
store water;
 Run-off river plants without pondages uses water as
it comes.
 The plant can use water as and when available.
 Since, generation capacity of these type of plants
these plants depend on the rate of flow of water,
during rainy season high flow rate may mean some
quantity of water to go as waste while during low
run-off periods, due to low flow rates, the generating
capacity will be low.

7. Classification of ROR Plants
Prepared by: Prof. Taji S. G.
7
 Run-off river plants with pondage:
 In these plants, pondage allows storage of water during lean
periods and use of this water during peak periods.
 Based on the size of the storage structure provided it may be
possible to cope with hour to hour fluctuations.
 This type of plant can be used on parts of the load curve as
required, and is more useful than a plant without pondage.
 If pondage is provided, tail race conditions should be such that
floods do not raise tail-race water level, thus reducing the head
on the plant and impairing its effectiveness.
 This type of plant is comparatively more conscientious and its
generating capacity is not depends on available rate of flow of
water.

8. Prepared by: Prof. Taji S. G.
8
 Pondage
 Pondage is the water that can back-up behind larger run-of-the-
river systems.
 This pondage is essentially a small amount of water
storage wherein water is built up during off-peak periods and
used during peak periods.
 In periods of low electricity demand, or when the plant is
inactive the water that would otherwise fall through
the spillways and be "wasted" is stored and used when it is
needed.
 Water that is built up in this pondage can result in the elevation
of the water varying between 1-1.5 meters during operation.
 A significant amount of pondage allows the plant to accomodate
hourly fluctuations.

9. Prepared by: Prof. Taji S. G.
9
 Pondage Factor:
 The pondage factor is a rough index of the amount
pondage needed when the stream flow is constant
and the plant is operational during specific
periods.
 It is calculated by the ratio of total inflow hours
per week to the hours the power plant will be
operated in that same period.
 For example, if a river has an inflow for seven days
a week and the plant operates for five of those days
for eight hours daily, P.F. = 7 * 24 / 5 * 8 = 4.2
 24-hour inflows and plant operation would have a
pondage factor of one.

10. Advantages of ROR Plants
Prepared by: Prof. Taji S. G.
10
 Cleaner power, fewer greenhouse gases:
 Like all hydro-electric power, run-of-the-river hydro
harnesses the natural potential energy of water,
eliminating the need to burn coal or natural gas to
generate the electricity needed by consumers and
industry.
 Less flooding/reservoirs:
 Without a reservoir, flooding of the upper part of the river
does not take place. As a result, people remain living at or
near the river and existing habitats are not flooded.
 Environmental impacts:
 Small, well-sited ROR projects can be developed with
minimal environmental impacts.

11. Disadvantages of ROR Plants
Prepared by: Prof. Taji S. G.
11
 "Unfirm" power :
 a run-of-the-river project has little or no capacity
for energy storage and hence can't co-ordinate the
output of electricity generation to match consumer
demand.
 Availability of sites:
 Site may not available easily.
 The potential power at a site is a result of the head
and flow of water.

12. Pumped Storage Power (PSP)
Plants
Prepared by: Prof. Taji S. G.
12
 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.

13. Prepared by: Prof. Taji S. G.
13

14. Component of PSP Plant
14
 Upper reservoir
 Like a conventional hydropower plant, a dam creates a
reservoir. The water in this reservoir flows through the
hydropower plant to create electricity.
 Lower reservoir
 Water exiting the hydropower plant flows into a lower reservoir
rather than re-entering the river and flowing downstream.
 Reversible turbine
 Using a reversible turbine, the plant can pump water back to
the upper reservoir.
 This is done in off-peak hours. Essentially, the second reservoir
refills the upper reservoir.
 By pumping water back to the upper reservoir, the plant has
more water to generate electricity during periods of peak
consumption.

15. 15
Component of PSP Plant
 Dam
 The dam for the project is planned to be of concrete gravity
type to create regulating pond for hydropower generation.
 Spillway
 The spillway and dissipation structures will radial gates on
ogee crest spillway with a cute and flip bucket.
 Surge Tank
 The surge tank characteristics will be determined in a way
to ensure:
 Stability of the operation of the power plant under small
load steps,
 Closure of the penstock discharge after load rejection in the
required time without excessive surge wave overpressure in
the penstock.

16. Prepared by: Prof. Taji S. G.
16
 Intake
 The function of an intake structure at a hydroelectric project
is to direct water to the water passages to the powerhouse
under controlled conditions.
 Generators
 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.
 Power lines
 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.
 Transformer
 The transformer inside the powerhouse takes the AC and
converts it to higher-voltage current
Component of PSP Plant

17. Prepared by: Prof. Taji S. G.
17
 Pure pumped storage
 Consists of two off stream reservoirs where electric
power generation is primarily dependent on the
pumping operation rather than on natural in flow into
the upper reservoir.
 Pumped-back pumped storage
 Generally comprises two reservoirs on the same river so
that electric generation relies on both natural inflow
and the water that is pumped back.
 Seasonal pumped storage
 It is an operation that balances the variability of natural
fluctuation of river flow, which is generally seasonal,
with demand, which may be more uniform and may
possibly vary in a direction opposite to supply.
Types of PSP Plants

18. Prepared by: Prof. Taji S. G.
18
 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.
 Allow great deal of flexibility in operational
schedules of system.
Advantages of PSP Plants

19. 19
 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. [The cost of electricity per unit during
high demand (peak load demand) is much more costly than
that of during off-peak demands. Thus pumped storage
plants have the advantages of generating electricity at
lower cost compared to other peak load plants (gas and
diesel power plants). Water is pumped back to the reservoir
during off-peak loads (eg: during night times). Therefore the
cost required to pump back is cheaper.]
 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.
Advantages of PSP Plants

20. Prepared by: Prof. Taji S. G.
20
 By adopting pump-storage plant in conjunction
with the thermal power plant reduces the
capacity of the thermal power plant (which is
used as base load plant) and allowed the
thermal power plant to operate at almost 100%
load factor.
 It also reduces the start and stop time of the
thermal power plant. This method is more
economical than conventional plants
particularly when an incremental cost of
hydroelectric plant is comparatively low and
cost of fuel in thermal plant is high.
Advantages of PSP Plants

21. Prepared by: Prof. Taji S. G.
21
 By seasonal storage through pumping, the
stream flow in other rivers could be used
which could otherwise run to waste. This the
major advantage of pumped storage power
plant.
 Pumped storage plant capacity is not limited
by the river flow and seasonal variations in
the flow. This is the advantage of pumped
storage plants which can be operated all over
the year in all seasons.
Advantages of PSP Plants

22. Prepared by: Prof. Taji S. G.
22
 These plants suffers from economical disadvantage as they
require a dual conversion of energy is required.
 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.
 The construction site is limited where the site conditions can
meet the pumped-storage requirements including geographical,
geological, transmission requirements.
Disadvantages of PSP Plants

23. Examples of PSP in India
23
 Bhira, Maharashtra, 150 MW
 Kadamparai, Coimbatore, Tamil Nadu, 400
MW (4 x 100MW)
 Nagarjuna Sagar PH, Andhra Pradesh, 810
MW (1 x 110MW + 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, 1000 MW
References:
1. https://en.m.wikipedia.org/ 2. https://www.cleanenergybc.org/ 3. https://www.scribd.com/