A hydroelectric power plant utilizes the potential energy of water stored at a high elevation behind a dam. Water is channeled from the dam through pipes to spin water turbines, which power generators to produce electricity. Hydroelectric power is efficient, cost-effective, and environmentally friendly as it produces no emissions. However, the initial costs of constructing large dams can be high.

2.  It utilizes the potential energy of water at a
high level for generation of electrical energy.
 These plants are generally located in hilly
areas where dams can easily be built.
 From the dam water is led to a water turbine.
 Water’s energy is used to move the prime
mover which in this case is __________

3.  The figure below shows a cross sectional view
of a Hydroelectric power plant
http://www.talgov.com/you/electric/corn.cfm

4.  Efficient
 Cost effective
 Environment friendly (no smoke or fumes are
produced)
 Simple in construction and requires less
maintenance
 Has longer life
 Does not require long starting time like a
steam power station.
 They can also help in irrigation and
controlling floods

5.  High capital cost due to construction of dam
 Transmission costs can be high depending on
the location of dam.

6.  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.
 The power companies make a lot of money by
selling the generated power during peak
hours at higher rates.

7.  Figure below shows a pumped storage hydro
power plant.

8.  Density=mass/volume
 W=m x g
 Density of water =1000Kg/m3
 hydraulic efficiency x electrical efficiency=
overall efficiency

9.  The power that can be extracted from a
waterfall depends upon its height and rate of
flow.
 The available hydro power can be calculated
by the following equation:
 P=9.8qh
 P=available water power[kW]
 q=water rate of flow [m3/s]
 h= head of water [m]

10.  A large hydropower station has a head of
324m and an average flow of 1370m3/s. The
reservoir of water covers an area of 6400Km2.
Calculate
◦ the available hydraulic power
◦ the number of days this power could be sustained if
the level of the impounded water were allowed to
drop by 1m.

11.  The available hydropower can be found using
the equation
 P=9.8qh
 P=9.8 x 1370 x 324=4350MW
 (b) we have to find the number of days ?
 Using the 1 m drop we find the
corresponding volume of water
 Volume = area x height =6400x106m2 x
1m=6400x106m3

12.  Rate of flow= 1370m3/s
 By looking at the units of rate of flow we can
deduce that time in seconds would be volume
divide by rate of flow
 t=6400x106/1370 = 4.67x106 s = 1298h
=54 days

13.  A hydro electric generating station is supplied
from a reservoir of capacity 5x106 cubic
meters at a head of 200 meters. Find the total
energy available in kWh if the overall
efficiency is 75%.

14.  Given data:
◦ V= 5x106m3
◦ h =200m
 q can be calculated as 5x106m3/s
 P=9.8qh =9.8x5x106x200 =9800000000 x
0.75(efficiency) kW
 E=PT
 E=(98x108 x 103 )W x 1s x0.75(efficiency)
 We need to find out the energy in kWh so we
divide the above value by (3600 x1000) and
get the answer which is 2.0416 x 106 kWh

15.  Find the advantages and disadvantages of
Pumped Storage Hydro Power Plants.
 Due one week from now. No late assignments
will be accepted.
 Submit hard copies only.

16.  Choose a suitable topic for a group
presentation. Group of min 2 and max 3.
 Submit the topic one week from now.
 In your submission include the reason why
you have chosen this topic. Name of group
members.*
 Presentations will be held the week before
midterm(approximately the 7th week)
*submission report should not exceed one
page.

17.  Combustion turbine (CT) power plants burn
fuel in a jet engine and use the exhaust
gasses to spin a turbine generator.
 The air is compressed to a very high
pressure. Fuel is then injected into the
compressed air and ignited, producing high-
pressure and high-temperature gas.
 This gas is used to move the turbine blades.
 The remaining gas is sent out through the
exhaust*

18.  The figure below shows a typical jet engine
http://en.wikipedia.org/wiki/File:Jet_engine.svg

19.  One of the advantages of combustion
turbines is that they can actually be designed
to be remotely controlled for unmanned sites.
 They offer fast startup times and fast
installation times.
 In most cases, the combustion turbine
generator package is a completely self-
contained unit.

20.  In fact, some of the smaller-capacity systems
are actually built on trailers so that they can
be moved quickly to sites requiring
emergency generation.
 Combustion turbines can be extremely
responsive to power system changes.
 They can go from no load to full load and vice
versa in a matter of seconds or in a matter of
minutes.

21.  The disadvantages are limited fuel options
(i.e., diesel fuel, jet fuel, or natural gas) and
inefficient use of exhaust heat.
 There are several environmental issues
related to the use of combustion turbines.
 Without appropriate treatment, the emissions
of undesirable gases can be very high.
 The high temperatures in the combustion
chambers will increase the production and
emission of nitric oxide gases.

22.  Sound levels can be high because CTs are
typically jet engines
 Have low efficiency

23.  *The exhaust gases after moving the turbine
can be passed through a heat exchanger
where they can be used to convert water into
steam and that steam can be used to move
secondary turbines.
 * The exhaust gases after passing through a
heat exchanger can also be used for heating
purposes in central heating systems.

24.  The following figure shows a diagram of CC
Power Plant
http://cogeneration.net/combined-cycle-power-plants/

25.  Find and list the applications of exhaust
gases.
 Quote proper references. Groups of min 2
max 3
 Due one week from today’s lecture. No late
assignments will be accepted.
 Submit hard copies only.

26.  Wind energy is converted into electrical
energy by means of windmills.
 Power produced is proportional to cube of
wind speed e.g. if wind speed is doubled, the
power produced is tripled.

27.  No fuel costs are involved
 Don’t cause air pollution
 Wind power is an example of renewable
energy.

28.  Cost of energy produced is high
 Constant dependence on wind
 Not considered to be base load units (units
which are part of 24 hour generation
production schedule)
 Wind mills need to be installed at sites where
there is unrestricted flow of wind e.g. at high
elevations.

29.  Photovoltaic type of solar power plant
converts the sun’s energy directly into
electrical energy.
 The solar panels use different materials which
convert solar into dc.
 The panels can be connected in series or
parallel to obtain the required
currents/voltages.
 During off-sun-peak periods a battery can be
used with this system.

30.  The dc energy is converted to ac by means of
an inverter.


31.  Renewable energy source
 Environment friendly
 Can be used to power small devices in remote
areas.

32.  Cost of solar panels are very high.
 Cost of conversion equipment is also very
high.
