Slides includes solar collector, solar energy, photovoltaic cell, tidal energy, biogas and biomass, ocean energy, recycling technique

1. Sustainable Energy (EEE-170)
By:- Dr. Gaurav K. Gugliani

2. UNIT-I

3. Introduction: The energy of a body is its capacity to do work. It is measured
the total amount of work that the body can do.
Different forms of energy are:
1. Mechanical energy (kinetic and potential)
2. Thermal (or) Heat energy
3. Chemical energy
4. Electrical energy
5. Nuclear energy
6. Electromagnetic energy
7. Gravitational energy
The S.I unit of energy is Joule or KJ or Watt.h.

4. Conventional and Non-Conventional sources energy
Conventional energy sources : The non-renewable sources of energy, which, if exhausted,
can not be replenished in a short time. Their reserves are limited and are considered very
precious.
1. Fossil fuel energy
a. Coal
b. Petroleum
c. Natural Gas
2. Hydraulic energy
3. Nuclear energy
Non-Conventional Energy Sources: The sources of energy which are being produced
continuously in nature and are inexhaustible are called renewable sources of energy
(or) non-conventional energy. Some of these sources are:
(a) Wind energy
(b) Tidal energy
(c) Solar energy
(d) Bio Energy (e) Energy from urban waste

5. (a) Wind energy
Winds are caused because of two factors.
1. The absorption of solar energy on the earth’s surface and in the atmosphere.
2. The rotation of the earth about its axis and its motion around the Sun.
A wind mill converts the kinetic energy of moving air into Mechanical
energy that can be either used directly to run the Machine or to run the
generator to produce electricity.
(b) Tidal energy
. Tides are generated primarily by the gravitational attraction between the earth
and the Moon. They arise twice a day in Mid-Ocean. The tidal range is only a
Meter.
Basically in a tidal power station water at high tide is first trapped in a
artificial basin and then allowed to escape at low tide. The escaping water is
used to drive water turbines, which in turn drive electrical generators

6. (c) Solar energy
Brief history of solar energy (or) Importance of solar energy:
Energy from the sun is called solar energy. The Sun’s energy comes
from nuclear fusion reaction that take place deep in the Sun. Hydrogen
nucleus fuse into helium nucleus. The energy from these reactions flow out
from the sun and escape into space.
4. Bio Energy:
This type of energy is obtained from organic matter.
It is of two kinds:
(i) Bio Gas:
Bio Gas is obtained from Gobar Gas Plant by putting cow dung into the plant. Besides
producing gas this plant converts gobar into manure. It can be used for cooking, lighting
and generation of electricity. 26.5 lakh bio gas plants had been established by the year
2003-04. They produce more than 225 lakh tonnes of manure. About 1828 large
community bio gas plants have been established in the country.
(ii) Bio Mass:
It is also of a source of producing energy through plants and trees. The purpose of bio
mass programme is to encourage afforestation for energy. So that fuel for the generation
of energy based on gas technique and fodder for the cattle could be obtained, 56 MW
capacity for the generation of bio mass energy has been installed.

7. 5. Energy from Urban Waste:
Urban waste poses a big problem for its disposal. Now it can be used for
generation of power. In Timarpur (Delhi) a power Ration of 3.75 MW capacity
has been set up to generate energy from the garbage

8. Merits of Non-conventional Source of Energy
Non-polluting: The major advantage of these non-conventional sources is that
they are non-polluting, unlike the other sources. The burning of firewood and
fossil fuels result in air pollution. This can be avoided by using these non-
conventional sources.
• Inexhaustible: The major problem while using conventional sources especially
fossil fuels is that they are exhaustible sources. It takes millions of years for
them to be renewed and replenished. But non-conventional sources are
renewable sources that do not get exhausted.
• Safe: Non-conventional energy extraction is safer. Many accidents occur while
extracting energy from mines. These accidents can be completely avoided.
• Low running cost: The cost of energy production and extraction is much lesser
for non-conventional sources if the initial cost of establishment is borne.
• Energy production: The non-conventional sources especially nuclear energy
results in the production of huge quantities of energy compared to the
conventional energy sources.

9. Demerits of Non-conventional Source of Energy
Inconsistent, Unreliable Supply
Low Efficiency Levels
Location-Specificity Means Lower Chances of Universality
Not Every Non-Conventional Energy Source Is Commercially Viable
High Capital Cost

10. The electromagnetic (EM) spectrum is the range of all types of EM radiation. Radiation
is energy that travels and spreads out as it goes – the visible light that comes from a
lamp in your house and the radio waves that come from a radio station are two types
of electromagnetic radiation. The other types of EM radiation that make up the
electromagnetic spectrum are microwaves, infrared light, ultraviolet light, X-
rays and gamma-rays.

11. SOLAR THERMAL COLLECTOR..
A SOLAR THERMAL COLLECTORS are special kind of heat exchangers
that transform solar radiation energy to internal energy of the transport
medium.
The major component of any solar system is the solar collector.
Collector is a device which absorbs the incoming solar radiation,
converts it into heat, and transfers this heat to a fluid (usually air, water,
or oil)flowing through the collector.
The solar energy thus collected is carried from the circulating fluid either
directly to the hot water or space conditioning equipment, or to a
thermal energy storage tank from which can be drawn for use at night
and/or cloudy days.
For domestic/ industrial water heating and space heating purposes the
solar thermal collectors are classified as..
1. FLAT PLATE SOLAR COLLECTORS.
AND
2. EVACUATED TUBE SOLAR COLLECTORS.

14. Solar Power Plant: Solar power plant is based on the conversion of sunlight into
electricity, either directly using photovoltaic (PV), or indirectly using concentrated
solar power (CSP). Concentrated solar power systems use lenses or mirrors and
tracking systems to focus a large area of sunlight into a small beam. Photovoltaic
converts light into electric current using the photoelectric effect. Concentrated solar
power plants first appeared in the 1980s
Components of Solar Power Plant:
1)Solar module
2) Controller
3) Batteries
4) Inverters
5) Lighting load

16. Solar Module
Solar panel refers to a panel designed to absorb the sun's rays as a source of
energy for generating electricity or heating. A photovoltaic (in short PV) module is
a packaged, connected assembly of typically 6×10 solar cells.
Solar Photovoltaic panels constitute the solar module of a photovoltaic system
that generates and supplies solar electricity in commercial and residential
applications. Each module is rated by its DC output power under standard test
conditions, and typically ranges from 100 to 365 watts.
An individual PV cell typically produces 0.6 watts and are joined in an module to
produce the required power

17. Controller:
Controller's main function is to make solar power system is always in the
vicinity of the maximum power generation in order to obtain maximum
efficiency.
The charge control usually the PWM (pulse width modulation) control, so
that the whole system is always running at maximum power point Pm near
the area.
Discharge control mainly refers to when the battery power shortage, system
failures, such as open or reversed when the battery cut off switch.
D.C. to A.C. Converter (Inverter)
Solar panels produce direct current which is required to be converted into
alternating current to be supplied to homes or power grid.

18. Battery:
Batteries are used to produce the power back or store the excess energy produced
during day, to be supplied during night
An electric battery is a device consisting of two or more electrochemical cells that
convert stored chemical energy into electrical energy.
Each cell has a positive terminal, or cathode, and a negative terminal, or anode.
The terminal marked positive is at a higher electrical potential energy than is the
terminal marked negative.
The terminal marked negative is the source of electrons that when connected to an
external circuit will flow and deliver energy to an external device.
When a battery is connected to an external circuit, electrolytes are able to move as
ions within, allowing the chemical reactions to be completed at the separate
terminals and so deliver energy to the external circuit.
It is the movement of those ions within the battery which allows current to flow
out of the battery to perform work. Although the term battery technically means a
device with multiple cells, single cells are also popularly called batteries.

19. Advantages:
Solar energy is a clean and renewable energy source.
Once a solar panel is installed, solar energy can be produced free of charge.
Solar energy will last forever whereas it is estimated that the world’s oil reserves
will last for 30 to 40 years.
Solar energy causes no pollution.
Solar cells make absolutely no noise at all. On the other hand, the giant machines
utilized for pumping oil are extremely noisy and therefore very impractical.
Very little maintenance is needed to keep solar cells running. There are no
moving parts in a solar cell which makes it impossible to really damage them.
In the long term, there can be a high return on investment due to the amount of
free energy a solar panel can produce, it is estimated that the average household
will see 50% of their energy coming in from solar panels

20. Disadvantages
Solar panels can be expensive to install resulting in a time-lag of many years for
savings on energy bills to match initial investments.
Electricity generation depends entirely on a countries exposure to sunlight; this
could be limited by a countries climate.
Solar power stations do not match the power output of similar sized
conventional power stations; they can also be very expensive to build.
Solar power is used to charge batteries so that solar powered devices can be
used at night. The batteries can often be large and heavy, taking up space and
needing to be replaced from time to time

22. What is biomass??
What is biomass??
The total mass of living matter within a given unit of environmental area.
given unit of environmental area.
Plant material, vegetation or agricultural waste used as a fuel or energy
source.

23. Converting biomass energy into a
useable
energy source
1.Direct incineration
1.Direct incineration
2.Bacterial Decay. (methane gas produced by the bacterial decay of
dead plants or animals.
animals.
3. Fermentation, Adding a yeast to biomass produces an alcohol
called ethanol.
produces an alcohol called ethanol.
4. Conversion, Biomass can be converted into gas or liquid fuels by
using chemicals or heat.

24. Biogas
• Biogas is a clean and efficient fuel.
• It is a mixture of:
– Methane (CH4)
– Carbon dioxide (CO2)
– Hydrogen (H2)
– Hydrogen sulphide (H2S)
• The chief constituent of biogas is methane (65%). Visit
www.seminarlinks.blogspot.com to download

25. Production of Biogas - The biogas plants
There are two types of biogas plants in usage for the
production of biogas.
These are:
• The fixed- dome type of biogas plant
• The floating gas holder type of biogas plant

26. 1.Raw materials required
• Forms of biomass listed below may be used along with water.
• Animal dung
• Poultry wastes
• Plant wastes ( Husk, grass, weeds etc.)
• Human excreta
• Industrial wastes(Saw dust, wastes from food processing
industries)
• Domestic wastes (Vegetable peels, waste food materials)
Fixed- dome type of biogas plant

27. 1.Construction
The biogas plant is a brick and cement structure having the following five
sections:
• Mixing tank present above the ground level.
• Inlet tank: The mixing tank opens underground into a sloping inlet
chamber.
• Digester: The inlet chamber opens from below into the digester which is a
huge tank with a dome like ceiling. The ceiling of the digester has an outlet
with a valve for the supply of biogas.
• Outlet tank: The digester opens from below into an outlet chamber.
Fixed dome type of Biogas Plant

28. Working of Fixed Dome type Biogas Plant
• The various forms of biomass are mixed with an equal quantity of water in the
mixing tank. This forms the slurry.
• The slurry is fed into the digester through the inlet chamber.
• When the digester is partially filled with the slurry, the introduction of slurry is
stopped and the plant is left unused for about two months.
• During these two months, anaerobic bacteria present in the slurry decomposes or
ferments the biomass in the presence of water.
• As a result of anaerobic fermentation, biogas is formed, which starts collecting in
the dome of the digester.
• As more and more biogas starts collecting, the pressure exerted by the biogas
forces the spent slurry into the outlet chamber.
• From the outlet chamber, the spent slurry overflows into the overflow tank.
• The spent slurry is manually removed from the overflow tank and used as manure
for plants.

30. Floating Gas Holder type of Biogas Plant
Construction
The floating gas holder type of biogas plant has the following chambers/
sections:
• Mixing Tank - present above the ground level.
• Digester tank - Deep underground well-like structure. It is divided into two
chambers by a partition wall in between.
• It has two long cement pipes
i) Inlet pipe opening into the inlet chamber for introduction of slurry.
ii) Outlet pipe opening into the overflow tank for removal of spent slurry.
• Gas holder - an inverted steel drum resting above the digester. The drum
can move up and down i.e., float over the digester. The gas holder has an
outlet at the top which could be connected to gas stoves.

31. Working
• Slurry (mixture of equal quantities of biomass and water) is prepared in the
mixing tank.
• The prepared slurry is fed into the inlet chamber of the digester through the
inlet pipe.
• The plant is left unused for about two months and introduction of more slurry is
stopped.
• During this period, anaerobic fermentation of biomass takes place in the
presence of water and produces biogas in the digester.
• Biogas being lighter rises up and starts collecting in the gas holder. The gas
holder now starts moving up.
• The gas holder cannot rise up beyond a certain level. As more and more gas
starts collecting, more pressure begins to be exerted on the slurry.
• The spent slurry is now forced into the outlet chamber from the top of the inlet
chamber.
• When the outlet chamber gets filled with the spent slurry, the excess is forced

33. Disadvantages of floating gas holder type biogas plant • Expensive • Steel drum
may rust • Requires regular maintenance
Advantages of biogas as a fuel • High calorific value • Clean fuel • No residue
produced • No smoke produced • Non polluting • Economical • Can be supplied through
pipe lines • Burns readily - has a convenient ignition temperature
Uses of biogas • Domestic fuel • For street lighting • Generation of electricity • If
compressed, it can replace compressed natural gas for use in vehicles
Advantages of biogas plants • Reduces burden on forests and fossil fuels • Produces
a clean fuel - helps in controlling air pollution • Provides nutrient rich (N & P) manure for
plants • Controls water pollution by decomposing sewage, animal dung and human
excreta.

34. Tidal Energy
 Tides are periodic rise and fall of water level of sea which are caused by the action
of sun and moon on the water on the earth.
 They are mainly caused by the gravitational attraction of the moon & Sun on the
water of solid earth & Oceans. 70% of tides are produced by the force due to
moon. Moon is the major factor in the tide.
 Two tidal cycles occurs during a lunar day of 24Hrs 50 Minutes. They are two high
tides and two low tides. Time between high tides & Low tides at any given
location is a little over 6 Hrs.
 A High tide will be experienced at a point which is directly under the moon. At the
Same time, a diametrically opposite point on the earth‘s surface also experience a
high tide due to dynamic balancing. Hence the Full moon as well as a No moon
produce a high tide.
 When the water is above the mean sea level, it is called flood tide and when the
level is below the mean level, it is called ebb tide. These tides can be used to
produce electrical power which is known as tidal power.

35. Basic Principle of Tidal Power Plant
A dam is constructed in such a way that a basin gets separated from the sea and a
difference in the water level is obtained between the basin and sea. The constructed
basin is filled during high tide and emptied during low tide passing through sluices and
turbine respectively. The Potential energy of the water stored in the basin is used to drive
the turbine which in turn generates electricity as it is directly coupled to an alternator.

36. Working of a Tidal
Power Plant
During high tide, when the level of
water in the sea is high, sea-water
flows into the reservoir of the barrage
and turns the turbines. The turbines
then turn the generator shaft to
produce electricity.
During low tide, the sea-water stored in the
barrage reservoir is allowed to flow out into
the sea. This flowing water also turns the
turbines and generates electricity. Thus, as
the sea-water flows in and out of the tidal
barrage during high and low tides, the
turbines rotate continuously to generate
electricity.

37. Advantages
 It is free from pollution as it does not use any fuel.
 The tides are totally independent on nature’s cycle of rainfall.
 This will also not produce any unhealthy waste like gases, ash, atomic refuse
which entails heavy removal costs.
 Another notable advantage of tidal power is that it has a unique capacity to
meet the peak power demand effectively when it works in combination with
thermal or hydroelectric system.

38.  These Power plants can be developed only if natural sites are available.
 These Power plants will be always located far away from the load centers. The
power generated must be transported to long distances. This increases the
transportation cost.
 The capital cost of the plant (Rs.5000/kw) is considerably large compared with
conventional-power plants (hydro, thermal).
 The supply of power is not continuous as it depends upon the timing of tides.
Therefore some arrangements (double basin or double basin with pump
storage) must be made to supply the continuous power. This also further
increase the capital cost of the plant.
 It is interesting to note that the output of power from tidal power plant varies
with lunar cycle, because the moon largely influences the tidal rhythm, where
as our daily power requirement is directly related to solar cycle.
Disadvantages

39. Ocean Thermal Energy Conversion (OTE
 Ocean Thermal Energy Conversion (OTEC) is a process that
can produce electricity by using the temperature difference
between deep cold ocean water and warm tropical surface
water.
 OTEC is an energy technology that converts solar radiation
to electric power .
 OTEC process uses temperature difference between cold
deep water (5 ℃) & warm surface water (27 ℃) to power a

40. This plant works on the principle of a closed Rankine Cycle.
Warm Water is used to evaporate working fluid like Ammonia or
halocarbon Refrigerant.
Evaporated Fluid expands in a low pressure turbine, which is
coupled with a turbo alternator to produce electricity.
Working Principle

42. Advantages of OTEC
 Helps in producing fuels such as hydrogen, ammonia, and methanol .
 Produces base load electrical energy .
 Produces desalinated water for industrial, agricultural, and residential uses .
 Is a resource for on-shore and near-shore Mari culture operations .
 Provides air-conditioning for buildings .
 Provides moderate-temperature refrigeration .
 Has significant potential to provide clean, cost-effective electricity for the
future.
 Food Aquaculture products can be cultivated in discharge water.
 Eco- friendly .
 Minimal maintenance costs compared to other power production plants.
 OTEC helps in mining .

43.  OTEC produced electricity at present would cost more than electricity generated from
fossils fuels at their current costs.
 No energy company put money in this project because it only had been tested in a
very small scale.
 Construction of OTEC plants and lying of pipes in coastal waters may cause localized
damage to reefs and near-shore marine ecosystem.
 OTEC plant construction and operation may affect commercial and recreational
fishing.
 Other risks associated with the OTEC power system are the safety issues associated
with steam electric power generation plants are : -
 • Electrical hazards,
 • Rotating machinery,
 • Use of compressed gases,
 • Heavy material-handling equipment, and
Disadvantages of OTEC

48. UNIT-III
Geothermal
Energy

49. Geothermal energy is the heat that comes from the sub-surface of the earth. It is
contained in the rocks and fluids beneath the earth’s crust and can be found as far
down to the earth’s hot molten rock, magma.
To produce power from geothermal energy, wells are dug a mile deep into
underground reservoirs to access the steam and hot water there, which can then
be used to drive turbines connected to electricity generators.
Three types of geothermal power plants
 Dry steam: Dry steam is the oldest form of geothermal technology and takes steam
out of the ground and uses it to directly drive a turbine.
 Flash: Flash plants use high-pressure hot water into cool, low-pressure water
 Binary: Pass hot water through a secondary liquid with a lower boiling point, which
turns to vapour to drive the turbine.

50. Geothermal Reservoirs
Reservoirs can be suspected in the
areas where we find :-
Geyser
Boiling mud pot
Volcano
Hot springs
The rising hot water & steam is
trapped in permeable & porous rocks
to form a geothermal reservoir.
Reservoirs can be discovered by
 testing the soil
 analyzing underground
temperature

51. Some Visible Source of Geothermal Energy

53. Magnetohydrodynamic (MHD) Power Generation
The working principle of MHD generator is based on Faraday’s Law. It states
that when a conductor is moved in a magnetic field an EMF is induced in the
conductor.
In an MHD system, hot gases act as the conductor. When gases are heated to
sufficient temperature by burning of fuel, one or more of the valence electrons
are displaced from their orbit in which they are spinning. Thus, the neutral
atoms are split into the positive and negative ion. These ions are the electrical
conductors.
After that, ionized gases are moved in a duct known as the MHD duct at very
high velocity. This movement of gas ions in the MHD duct in which strong
magnetic field is applied leads to the electromagnetic induction and an EMF is
induced in the pair of electrodes. The electrodes are connected to the external
circuit and they deliver current to the external load.

54. The three major components of an MHD generator are shown in
Figure. These are:
•MHD duct
•magnetic field and
•electrodes.

55. Advantages
 It converts heat energy directly into electrical energy and hence conversion
efficiency is high.
 It has no moving parts.
 On and OFF time is very low.
 It is a pollution free system.
 The size of MHD power plants is small as compared to conventional power plants for
same power output.
 The cost of power generation per unit is less.
 The operational and maintenance costs are low.
 The efficiency of MHD plants is 50% whereas the efficiency of most efficient
conventional power plants is about 40%.

56. Disadvantages
 It has high fluid friction losses and heat transfer losses.
 A large voltage drop takes place across the gas film.
 The requirement of large-sized magnets increases the cost of an MHD
system.
 Working temperature ranges from 200°K to 2400°K. This causes fast
corrosion of components.

57. The fuel cell is an electrochemical devise, which converts chemical energy of
the fuel to electricity by combining gaseous hydrogen with air in the absence of
combustion. The basic principles of operation of the fuel cell is similar to that
of the electrolyser in that the fuel cell is constructed with two electrodes with
a conducted electrolyte between them.
Fuel Cell
Principle of Fuel Cell
 Fuel cell is a device that converts the chemical energy from fuel into electrical
energy through a chemical reaction with oxygen.
 Every fuel cells has two electrodes, one positive and one negative called anode and
cathode respectively.
 Every fuel cell also has an electrolyte which carries electrically charged particles from
one electrode to the other and a catalyst which speeds up the reaction at the
electrodes.

58. Working of Fuel
Cell
Two main electrochemical reactions occur in the fuel cell. One at the anode (anodic
reaction) and one at the cathode.
At the anode, the reaction releases hydrogen ions and electrons whose transport is crucial
to energy production.
H22H+ + 2e-
The hydrogen ion on its way to the cathode passes through the polymer membrane while
the only possible way for the electrons is though an outer circuit. The hydrogen ions
together with the electrons of the outer electric circuit and the oxygen which has diffused
through the porous cathode reacts to water.

59. TYPES OF FUEL CELLS:
There are following many types of fuel
cells. They are basically classified
based on electrolyte used:
i. Alkaline fuel cell
ii. Molten carbonate fuel cell (MCFC)
iii. Phosphoric acid fuel cell (PAFC)
iv.Proton exchange membrane (PEM)

60. In this type of fuel cell a solution of potassium
hydroxide (KOH) in water is used as electrolyte.
• Efficiency is about 70% and operating
temperature is 150ºC to 200ºC.
• Cell output range from 300W to 5kW.
ALKALINE FUEL
CELL

61. MOLTEN CARBONATE FUEL CELL (MCFC)
These cells use high temperature compounds
of salt carbonates i.e. 𝑁𝑎2 𝐶𝑜3 or Mg𝐶𝑜3 as
the electrolyte.
• Efficiency ranges from 60% to 80% and
operating temperature is about 650ºC.

62. These cells use phosphoric acid as
electrolyte.
• Efficiency ranges from 40% to 80% and
operating temperature is between 150ºC to
200ºC.
PHOSPHORIC ACID FUEL CELL (PAFC)

63. These cells work with a polymer electrolyte in
the form of thin, permeable sheet.
• Efficiency is about 40% to 50% and operating
temperature is about 80ºC.
• Cell outputs ranges from 50 to 250 kW.
• These solid flexible electrolyte does not leak or
crack.
PROTON EXCHANGE MEMBRANE (PEM) FUEL CEL

64. These fuel cells use a hard ceramic compound of
metal (like calcium or zirconium) oxides (𝑂2) as
electrolyte.
• Efficiency is about 60% and opening temperature
is about 1000ºC.
SOLID OXIDE FUEL CELL (SOFC)

65. •High Efficiency- when utilizing co-generation,
fuel cells can attain over 80% energy efficiency
•Good reliability- quality of power provided does
not degrade over time.
•Noise- offers a much more silent and smooth
Advantages of
Fuel Cell

66. •Expensive to manufacture due the high cost of
catalysts (platinum)
•Lack of infrastructure to support the distribution
of hydrogen
•A lot of the currently available fuel cell
Disadvantages of
Fuel Cell