2. Introduction to Energy Science and Energy Technology,
Renewables and Conventionals
• What is Energy ?-Energy, Exergy, Anergy-Forms of Energy-Various Sciences
and Energy Science-Energy Technology-Energy, Man and Environment-Law of
Conservation of Energy-Thermodynamics and Energy Analysis -First and
Second Laws of Thermodynamics.
• Energy chains and Energy Links- Energy Resources-Primary Energy -
Intermediate Energy-Usable (Secondary) Energy -Energy Calculations-Units
and Conversion Factors.
• Conventional, Renewable, Non-conventional and Alternate Sources of
Energy. Energy Demand - Energy Requirements by various sectors-Energy
Routes of conventional energy-Renewable Energy. Wind Energy-Solar Energy
-Biomass Energy-Energy from Ocean-Geothermal Energy-Changing Energy
Consumption trends.
• Electrical Energy - Load curves-Peak Load/Base Load, Generating Units-
Energy Storage Plants. Energy
• Supply System in India - Coal and Coal Technologies-Petroleum and Natural
Gas-Nuclear Fuels and Power Plants-Hydro Resources and Power Plants-
Energy Strategies-Energy Conservation-Energy Audit-Cost of energy-Scope of
subject - Summary - Questions.
2 Energy science & Technology 9/22/2014
3. What is Energy?
The concept drawn from classical physics
while explaining work
Energy is the capability to produce motion; force,
work; change in shape, change in form, etc.
Energy exists in several forms. Energy transformations are
responsible for various activities
.
3 Energy science & Technology 9/22/2014
7. Energy exists in many forms such as
• chemical energy (Ech),
• nuclear energy (Enu),
• solar energy (Eso),
• mechanical Energy (Eme)
• electrical energy (Eec),
• internal energy in a body (Ein),
• bio-energy in vegetables and animal bodies (Ebi),
• thermal energy Eth, etc.
7 Energy science & Technology 9/22/2014
12. Energy Technology?
distinguish between 'Energy' 'Useful
Energy' and Worthless Energy' with
reference to useful work content.
Energy Science
Science is a systematized body of knowledge
about any department of nature, internal or
external to man.
The energy science deals with scientific
principles, characteristics, laws, rules,
units/dimensions, measurements, processes etc.
about various forms of energy and energy
transformations.
Science involves experimentation, measurement,
mathematical calculations, laws, observations, etc.
12 Energy science & Technology 9/22/2014
13. Energy Technology
concerned with 'demand' for
various forms of secondary energy
(usable energy) and the methods of
'supply‘
various alternative routes.
deal with plants and processes
involved in the energy
transformation and analysis of the
useful energy (exergy) and
worthless energy (anergy). Energy
Technology includes study of
efficiencies and environmental
aspects of various processes.
The applied part of energy
sciences for work and processes,
useful to human society, nations
and individuals is called Energy
Technology. Energy
technologies deal with various
primary energies, processing,
useful energies and associated
plants and processes. The
coverage including exploration,
transportation, conversion,
utilization.
13 Energy science & Technology 9/22/2014
14. Mother Science
Energy science has
interface with every other
science. Energy science is
the mother science of
physics, thermodynamics,
electromagnetic, nuclear
science, mechanical
science, chemical science,
biosciences etc. Each
science deals with some
'activity'. Energy is the
essence of activities.
14 Energy science & Technology 9/22/2014
15. Energy technology deals with the complete energy route and its steps
such as :
- Exploration of energy resources- Discovery of new sources
- Extraction or Tapping of Renewable or Growing of Bio-farms
- Processing
- Intermediate storage
-Transportation/Transmission
- Reprocessing
- Intermediate storage
- Distribution
-Supply
- Utilization.
15 Energy science & Technology 9/22/2014
17. Energy Strategies include
long term policies,
short-term and Mid-Term
Planning,
Economic planning,
Social and Environmental Aspects
of various energy routes.
These are analyzed from the
perspectives of the world, Region,
Nation, States, sub-regions,
various economic sectors,
communities and individuals
Energy Science and Energy
Technology is of immense
interest to the Planers,
Economists, Scientists,
Engineers, Professionals
and Industrialists, Societies
and Individuals, etc.
17 Energy science & Technology 9/22/2014
18. Various Sciences and Energy Science
Physics : It is a branch of natural science dealing
with properties and changes in matter and energy.
Physics deals with continuous changes in matter and
energy and includes mechanics, electromagnetic,
heat, optics, nuclear energy etc. and laws governing
the energy transformations. Energy science has
been developed by Physicists.
Thermodynamics : It is a branch of physics dealing
with transformation of thermal energy into other
forms of energy, espe6ially mechanical energy and
laws governing the conversions. Thermodynamics
plays a dominant role in Energy Technologies.
Biological Sciences deal with biomass and
biological processes.
Bio sciences are concerned with the physical
characteristics,' life processes of living vegetation
and animals on land and in water and their remains.
Biomass is the matter derived from vegetation and
nimals. Biomass is a natural renewable source of
energy and is being given highest priority in recent
years. (1980s onwards) Biomass is the important
renewable energy for the 21st century.
Chemistry is a science dealing with composition and
properties of substances and their reactions to form
other substances. The chemical reactions are
accompanied by release of thermal energy
(exothermic reactions) or absorption of thermal
energy (endothermic reaction). Chemical Reactions
are intermediate energy conversion processes.
Many useable energy forms are obtained from
chemical reactions. (e.g. petroleum products,
synthetic gases and liquids). Natural Gas and
Petroleum products are most important energy forms
in the world during 20th and 21st century.
Electromagnetic : The flow of electrons and
electrical charges through a circuit produces
associated electromagnetic fields and electrical
energy. Electromagnetic is a branch of physics
dealing with electricity, magnetism and various
transformations of ·other forms of energy
(mechanical, thermal, chemical etc.) into electrical I
energy and vice-versa. Electrical energy is the most
superior; efficient, useful form of energy which can
be generated, transmitted, distributed, controlled,
utilized. Electrical energy is an intermediate and
secondary form of energy being used very widely all
over the world.
18 Energy science & Technology 9/22/2014
24. Science : Finally figured out
24 Energy science & Technology 9/22/2014
25. Energy science and other sciences are co-related
25 Energy science & Technology 9/22/2014
26. Energy Technology and Energy
Sciences
Energy Science and Technology deal with several useful natural and artificial (man-made)
energy systems. The basic objectives are to extract, convert, transform,
transport, distribute and reconvert different types of energy with least pollution and
with highest economy.
Energy technology is a systematized knowledge of various branches of energy flow
and their relationship with human society as viewed from scientific, economic,
social, technological, industrial aspects for benefit of man and environment.
Science of energy is concerned with the natural rules and characteristics of energy,
energy resources, energy conversion processes and various phenomena related
directly or indirectly to the extraction conversion and use of energy resources
essential to the economy and prosperity.
Science of energy deals with the phenomena related with energy conversion plants and
processes for generating secondary energy (electricity, heat, steam, fuel, gas, etc.) by
converting various kinds of primary energy sources. It also deals with aspects of
useful energy, (exergy), work, power, efficiency and worthless energy (anergy)
losses etc.
26 Energy science & Technology 9/22/2014
27. Energy, Man and Environment
Close liason between Energy, Energy Conversion Processes, Man and Environment.
27 Energy science & Technology 9/22/2014
29. Renewables & Non-conventionals
Renewables
Conventional & Non-conventionals
Renewables are those which are renewed by the
nature again and again and their supply is not
affected by rate of consumption
Sources: solar, wind, geothermal, ocean thermal,
ocean wave, ocean tide, mini-hydro, bio-mass,
chemicals, waste fuels etc. These are available
from nature in renewable but
periodic/intermittent form.
Global Status: Renewables in the world is less
than 2% (excluding hydro). This is likely to
increase to about 10% by 2000 AD and to
about 15% by 2015· AD.
Merits & Demerits: Renewables are cheap, clean
energy resources. However, solar and wind
sources are intermittent, diffused and their
conversion technologies are presently costly
and suitable only of smaller plant capacities.
Energy resources which are in
use during 1950-1975 are called
conventionals.
Energy resources which are
considered for large-scale use
after 1973 oil crisis are called
Non-conventional or Alternate.
29 Energy science & Technology 9/22/2014
32. Renewables and Non-conventionals
Feature
Conventional/
Nonrenewable
Renewables
- Technologies Established Under development
- Plant size Large (MW range) Small (kW range)
- Main Power Plants Suitable Not sufficient
- Energy density of source High Low
- Pollution problems More Less
- Energy reserves Limited Will continue to renew
- Cost of generation Low High
-Storage Easy Uneconomical
32 Energy science & Technology 9/22/2014
33. Conventional and Renewable Resources for Electrical Generation
Conventional Alternative, Renewable*
Coal Wind power
Petroleum oils Solar power
Natural Gas Geothermal
Hydro Ocean waves
Nuclear fission fuels Ocean tide
Fire-wood Bio-mass fuels
Waste-fuels
Bio-gas
Synthetic gases
Nuclear fusion fuels+
Fuels for fuel cells
Firewood*
Ocean-algae fuel
Ocean salinity gradient+
*Considered on priority after 1973 oil crisis.
+ Not yet on commercial scale. *For power plants
33 Energy science & Technology 9/22/2014
34. Non-renewable energy resources can not be get replenished
after their consumption. e.g. coal once burnt is consumed
without replacement of the same (Fossil fuels, Nuclear fission
fuels).
The energy resources which are formed very slowly in nature
and which are likely to be exhausted in a few more decades or
centuries are called Non-renewable. World is presently
dependant on such resources (90% supplies of world primary
resources are by Nonrenewables-1990)
34 Energy science & Technology 9/22/2014
37. Energy Demand
Rising rapidly with growing
population and
industrialization.
Secondary (usable) energy forms
of importance are :
- Fuels: Coal, petroleum (Oil),
Natural Gas, Chemicals, Fire-wood
etc.
- Electrical power
- Chemicals for processes.
- Renewables such as solar heat,
bio-gas, wind, bio-mass etc.
Energy in various secondary
(usable) forms for various
activities.
- Domestic, Social, Municipal -
Agriculture
- Commercial
- Industrial
- Transportation
- Defence, Medical, Scientific
work etc.
37 Energy science & Technology 9/22/2014
38. Increasing demand of primary energy resources
in India
38 Energy science & Technology 9/22/2014
45. Total annual primary energy consumption between 1994 and 2004. Key: kWh, kiloWatt hours.
Source: US Dept of Energy Information Administration
45 Energy science & Technology 9/22/2014
46. World consumption of primary energy by fuel type between 1994 and 2004.
Key: GSWW, geothermal, solar, wind and wood/waste; kWh, kiloWatt hours
46 Energy science & Technology 9/22/2014
47. Energy consumption per capita in 1994 and 2004, by region. Total is the
average global energy use per capita. Key: kWh, kiloWatt hours
47 Energy science & Technology 9/22/2014
48. Increase in primary energy consumption per capita between 1994 and 2004. Total is the
average global increase, per capita, over the period.
48 Energy science & Technology 9/22/2014
49. Carbon dioxide emissions from fossil fuel consumption, in 1994 and 2004, by region
49 Energy science & Technology 9/22/2014
50. Percentage increase in carbon dioxide emissions from fossil fuel consumption, between 1994
and 2004, by region.
Note: emissions in Eurasia actually fell slightly. Total is the average global increase over the
period.
50 Energy science & Technology 9/22/2014
51. Projected increase in primary energy consumption from 2003 to 2030, by energy
type.
Key: energy "other" in this case is hydroelectricity together with renewables
(GSWW); kWh, kiloWatt hours
51 Energy science & Technology 9/22/2014
52. Projected percent increase in primary energy consumption from 2003 to 2030, by
energy type.
Key: energy "other" in this case is hydroelectricity together with renewables
(GSWW)
52 Energy science & Technology 9/22/2014
53. The cycle consisting of the gross
domestic product and the demand
for primary energy, which
determines the standard of living.
Correlation between the gross domestic product and the demand for primary energy of selected countries in 2000
The higher the demand for primary energy is in a country, the higher is its
gross domestic product and therefore the (measurable) standard of living.
53 Energy science & Technology 9/22/2014
54. During past several decades, the energy demand of the world has continued to
increase at an annual growth rate of 3 to 4% due to the following reasons:
- Increasing per capita energy consumption with increasing standard of living.
- Increasing population.
- Increasing industrialization.
-Invention of large energy conversion machines. (Electric motors, gas turbines internal
combustion engines etc.
- Increasing transportation.
- Development of energy supply systems and availability of electrical energy and fuels.
Energy needs of man vary with life-style, climatic conditions, season, industrial
progress etc.
54 Energy science & Technology 9/22/2014
55. Industry needs coal, steam, electrical energy, furnace oils,
diesel, chemicals, lubricating oils etc. Raw materials, like steel,
copper, aluminum, etc. are produced by energy-intensive
processes. Water is pumped and distributed by using motor-pumps
which consume electrical energy. Transportation by
road, rail, ocean and air requires high energy input.
Higher per capita energy consumption of a country indicates
industrial progress and prosperity. For example, the annual per
capita electrical energy consumption of India in 1988 was 2388
kWh against 92,000 kWh of USA.
55 Energy science & Technology 9/22/2014
56. Historical Review of Growing Energy Demand of Man
Daily per capita Energy Consumption, kWh per day, per capita
Historical age Food Agriculture Domestic Industry Transport Total
-Cave Man
(10,00,000 years ago)
3 3
-Hunting Man
(1,00,00 years ago) 4 3 7
- Agricultural Man (5000 BC)
5 2 6 13
-Industrial Man
- (20th Century) 10 5 60 100 85 260
- Technologically advanced
man (21st Century)
10 5 60 150 185 410
1 kWh = 1 kilo-watt hour = 1000 Watt. hour = 3.6 x 106 J
56 Energy science & Technology 9/22/2014
57. India’s electrical power plants:
India's demand for electrical energy is growing at an annual increase by 8 to 10%.
Conventional
Relative use % Non conventional
Renewable
Relative
use %
1. Coal Fired Steam Thermal 68 1. Wind-power
2. Hydro-electric Plants 25 2. Solar power
3. Nuclear Plants 5 3. Geothermal
4. Gas-Turbine Plants 4. Ocean-Thermal
5. Combined Cycle 2 5. Ocean-waves
-Gas 6. Waste incineration
-Steam 7. Biomass
8. Fuel cells
6. Cogeneration Plants 1 9. Nuclear Fusion
-Heat 10. Others
-Steam Total <1%
- Electricity
7. Renewable 1
57 Energy science & Technology 9/22/2014
58. Age of Renewables and
Alternatives
Fossil Fuel age is expected to span only 1000 years
of human civilization (1700 AD to 2700 AD).
The prices of petroleum are increasing.
Environmental imbalance created by combustion
of coal; nuclear waste deposits, deforestation by
hydro power plants etc.
58 Energy science & Technology 9/22/2014
59. Some alternate energy power plants have been built
on commercial basis in several advanced countries.
Developing countries have also initiated ambitious
projects for harnessing the Renewables.
Present installed capacities of non-conventional
renewable energy plants (except hydro) in India are
negligible.
59 Energy science & Technology 9/22/2014
60. U.S. Energy Consumption by Energy Source, 2003-2007 (Quadrillion Btu)
Energy Source 2003 2004 2005 2006 2007
Total 98.209 100.351 100.503 99.861 101.605
Fossil Fuels 84.078 85.830 85.816 84.662 86.253
Coal 22.321 22.466 22.795 22.452 22.786
Coal Coke Net
0.051 0.138 0.044 0.061 0.025
Imports
Natural Gasa 22.897 22.931 22.583 22.191 23.625
Petroleumb 38.809 40.294 40.393 39.958 39.818
Electricity Net
0.022 0.039 0.084 0.063 0.106
Imports
Nuclear 7.959 8.222 8.160 8.214 8.415
Renewable 6.150 6.261 6.444 6.922 6.830
Biomassc 2.817 3.023 3.154 3.374 3.615
Biofuels 0.414 0.513 0.595 0.795 1.018
Waste 0.401 0.389 0.403 0.407 0.431
Wood Derived
Fuels
2.002 2.121 2.156 2.172 2.165
Geothermal 0.331 0.341 0.343 0.343 0.353
Hydroelectric
2.825 2.690 2.703 2.869 2.463
Conventional
Solar/PV 0.064 0.065 0.066 0.072 0.080
Wind 0.115 0.142 0.178 0.264 0.319
a Includes supplemental gaseous fuels.
b Petroleum products supplied, including natural gas plant liquids and crude oil burned as fuel.
c Biomass includes: biofuels, waste (landfill gas, MSW biogenic, and other biomass), wood and wood-derived fuels.
MSW=Municipal Solid Waste.
Note: Ethanol is included only in biofuels. In earlier issues of this report, ethanol was included both in petroleum and biofuels,
but counted only once in total energy consumption. Totals may not equal sum of components due to independent rounding.
Data for 2007 is preliminary.
Sources: Non-renewable energy: Energy Information Administration (EIA), Monthly Energy Review (MER) March
2008, DOE/EIA-0035 (2008/03) (Washington,DC, March 2008,)
60 Energy science & Technology 9/22/2014
67. World Renewables Energy Sources
Resource Form of delivered energy
(Application)
comments
Solar: Total Solar radiation ab-sorbed
by the earth and its
atmosphere is 3.8 x1024 J/yr.
Low temperature heat (space
heating water heating and
electricity)
Million of solar water heaters
and solar cookers are in use.
Solar cells and power towers
are in operation.
Wind: The kinetic energy
available in the atmosphere
circulation is 7.5 x1020 J
Electricity Several multi-megawatt wind
turbines are in operation and
many more in construction.
Mechanical energy (Pumping
transport)
There are numbers of small
wind turbines and wind
pumps in use.
Biomass: Total solar radiation
absorbed by plants is 1.3 x 1021
J/yr.
High temperature heat
(cooking, smelting etc.)
Bio-mass (principally wood
accounts for about 15% of the
world's (commercial fuel)
consumption; it provides over
80% of the energy needs of
many developing countries.
The worlds standing biomass
has an energy content of about
1.5 x 1021 J.
Bio-gas (cooking, mechanical
power etc.)
There are millions of biogas
plants in operation, most of
them are in China.
67 Energy science & Technology 9/22/2014
68. World Renewables Energy Sources
Resource Form of delivered energy
(Application)
comments
Alcohol(transport) Several thousand, million liters of alcohol
are being produced notably in Brazil and
the U.S. Production is increasing rapidly ;
many countries have lunched liquid bio-fuel
programmes.
Geothermal: The heat flux from
the earth's interior through the
surface is 9.5 x 1020J/yr.
Low temperature heat
(bathing. space and water
heating)
Geothermal energy supplies about 5350
MW of heat for use in bathing principally
in Japan, but also in Hungary, Iceland and
Italy. More than a lakh houses are supplied
with heat from geothermal wells. The
installed capacity is more than 2650 MW
(thermal).
The total amount of heat stored in
water or stream to a depth of 10
km is estimated to be
4 x 1021J ; that stored in the first 10
km of dry rock is around 1027 J.
Electricity Installed capacity is more than 2500 MW
but output is expected to increase more
than seven fold by 2000.
68 Energy science & Technology 9/22/2014
69. World Renewables Energy Sources
Resource Form of delivered
energy (Application) comments
Tidal: Energy dissipated in connection
with slowing down rotation of the
earth as a result of tidal action is
around 1026 J/yr.
Electricity Only one large tidal barrage is in operation (at La
Rance in France) and there are small schemes in
Russia and China. Total installed capacity is about
240 MW and the output around 0.5 TWh/yr.
Wave: The amount of energy stored
as kinetic energy in waves may be of
the order of 1018 J.
Electricity The Japanese wave energy research vessel, the
Kaimei, has an installed capacity of about 1 MW.
There are, in addition several hundred wave
powered navigational buoys: Designs after large
prototype wave energy converters are being drawn
up.
Hydro: The annual precipitation land
amounts to about 1.1 x 1017 kg of
water. Taking the average elevation of
land area as 840 m, the annually
accumulated potential energy would
be
9 x 1020 J.
Electricity Large hydroscheme15 provide about one quarter of
the world'l5 total electricity supply and more than
40% of the electricity used in developing countries.
The installed capacity is more than 363 GW. The
technically usable potential is estimated to be 2215
GW or 19000 TWb/yr. There are no accurate
estimates of the number of capacity of small
hydroplants currently in operation.
69 Energy science & Technology 9/22/2014
70. Primary
Energy
Resources
Non-electric
routes
World’s 48%
12% by non-commercial
route
World’s 40%
Electrical route
Final Energy
consumption
Two alternate route of energy supply
70 Energy science & Technology 9/22/2014
72. .
The yield ratio of the total sequence with n = 2 respectively n = 3 stations is calculated
according to the product rule
.
The factors have values which depend on the state of technological development in
every county. At the beginning of the 21. century
the values in fully developed countries were
72 Energy science & Technology 9/22/2014
73. Electrical energy
route
Primary Energy Processing Electrical
power plant
Electrical energy
Consumer
73 Energy science & Technology 9/22/2014
83. Global primary energy structure, shares (%) of oil and gas, coal,
and non-fossil (zero-carbon) energy sources - historical
development from 1850 to 1990 and in SRES scenarios. Each
corner of the triangle corresponds to a hypothetical situation in
which all primary energy is supplied by a single source - oil and
gas on the top, coal to the left, and non-fossil sources
(renewables and nuclear) to the right. Constant market shares of
these energies are denoted by their respective isoshare lines.
Historical data from 1850 to 1990 are based on Nakic´enovic´ et
al. (1998). For 1990 to 2100, alternative trajectories show the
changes in the energy systems structures across SRES
scenarios. They are grouped by shaded areas for the scenario
families A1B, A2, B1, and B2 with respective markers shown as
lines. In addition, the four scenario groups within the A1 family
A1B, A1C, A1G, and A1T, which explore different technological
developments in the energy systems, are shaded individually. In
the SPM, A1C and A1G are combined into one fossil-intensive
group A1FI. For comparison the IS92 scenario series are also
shown, clustering along two trajectories (IS92c,d and
IS92a,b,e,f). For model results that do not include non-commercial
energies, the corresponding estimates from the
emulations of the various marker scenarios by the MESSAGE
model were added to the original model outputs.
83 Energy science & Technology 9/22/2014
84. Global renewable energy potentials for 2020 to 2025, maximum technical
potentials, and annual flows, in EJ. Data sources: Watson et al., 1996;
Enquete-Kommission, 1990.
Consumption Potentials by Long-term
Technical
Potentials
Annual
1860-1990 1990 2020-2025 Flows
Hydro 560 21 35-55 >130 >400
Geothermal - <a 4 >20 >800
Wind - - 7-10 >130 >200,000
Ocean - - 2 >20 >300
Solar - - 16-22 >2,600
>3,000,0
00
Biomass 1,150 55 72-137 >1,300 >3,000
Total 1,710 76 130-230 >4,200
>3,000,0
00
84 Energy science & Technology 9/22/2014
85. Non-electrical energy route
Primary energy Processing Secondary
energy
Transport by
road/rail/ocean/pipeline
Consumer
85 Energy science & Technology 9/22/2014
86. Renewable Energy sources like wind, solar heat,
waves etc. cannot be stored in original natural
form. It is converted continuously to electrical
form. transmitted, distributed and utilized without
long-term intermediate storage. The Renewables
are available free of cost. Hence, consumption of
renewable should be maximized. Non-renewable
should be conserved for some more decades /
centuries.
86 Energy science & Technology 9/22/2014
91. Introduction
• Solar energy is a time dependent and intermittent
energy resource
• The need for energy storage of some kind is
almost immediate evident for a solar electric
system.
• solar energy is most available will rarely coincide
exactly with the demand for electrical energy
• high insolation times could be used to provide a
continuous electrical output or thermal output
91 Solar Energy Storage 9/22/2014
92. Storage of solar energy in a
solar system may:
• Permit solar energy to be captured when
insolation is highest
• it possible to deliver electrical load power demand
during times
• Be located close to the load
• Improve the reliability of the solar thermal as well
as solar electric system
• Permit a better match between the solar energy
input and the load demand output
92 Solar Energy Storage 9/22/2014
93. Optimum capacity of an energy
storage system
• The expected time dependence of solar radiation
availability.
• The nature of load to be expected on the process.
• The degree of reliability needed for the process.
• The manner in which auxiliary energy is supplied.
• The size of the solar thermal power system or solar-electric
generator.
• The cost per kWh of the stored energy.
• The permissible capital cost allocated to storage.
• Environmental and safety considerations.
• An economic analysis that determines how much of the
total usually annual loads should be carried by solar and
how much by auxiliary energy sources. 93 Solar Energy Storage 9/22/2014
95. Thermal Storage
Energy can be stored by
heating, melting or
vaporization of material,
and the energy
becomes available as
heat.
I. Sensible heat
storage
II. Latent heat
95 Solar Energy Storage 9/22/2014
96. I. (A ) water storage
The most common heat transfer fluid for a solar
system is water, and the easiest way to store thermal
energy is by storing the water directly in a well
insulated tank.
Characteristics for storage medium
• It is an inexpensive, readily available and useful
material to store sensible heat.
• It has high thermal storage capacity.
• Energy addition and removal from this type of
storage is done by medium itself. thus
eliminating any temperature drop between
transport fluid and storage medium.
96 • PSuolmar Epneirngyg Stocraogest is small 9/22/2014
97. I. (B) Packed Bed Exchanger
Storage
Sensible heat storage with air as the energy transport
mechanism, rock, gravel, or crushed stone in a bin has the
advantage of providing a large, cheap heat transfer
surface.
Rock does have the following advantages over water
• Rock is more easily contained than water.
• Rock acts as its own heat exchanger, which reduces total
system cost.
• It can be easily used for thermal storage at high
temperatures, much higher than 100°C; storage at high
temperature where water can not be used in liquid form
without an experience, pressurized storage tank.
• The heat transfer coefficient between the air and solid is
high.
• The cost of storage material is low.
• The conductivity of the bed is low when air flow is not
97 Solar Energy Storage 9/22/2014
99. II. (B) Latent heat storage
Materials that undergo a change of phase in a suitable temperature range may be
useful for energy storage
• The phase change must be accompanied by high latent heat
• The phase change must be reversible over a very large number of cycles without
degradation.
• The phase change must occur with limited super cooling.
• Means must be available to contain the material and transfer heat into it and out
of it.
• The cost of materials and its containers must be reasonable.
• Its phase change must occur close to its actual melting temperature.
• The phase change must have a high latent heat effect, that is, it must store large
quantities of heat.
• The material must be available in large quantities.
• The preparation of the phase changing material for use must be relatively
simple.
• The material must be harmless (non-toxic, non-inflammable, non-combustible,
non-corrosive).
• A small volume change during the phase change.
• The material should have high thermal conductivity in both the phases.
99 Solar Energy Storage 9/22/2014
100. Materials for phase change energy
storage.
• Glauber's salt (Na2S04.10 H20), water, Fe(N03)2 .6
H20, and salt Eutectics
• Organic compound or substances serve as heat
storage materials Paraffin and fatty acids
• Refractory materials (MgO, Al203, SiO2) are also
suitable for high temperature sensible heat storage
in addition to Rock or pebble bed storage. Some
thermal storage materials such as ZnCI2, Na(OH)3,
NaOH, KOH-ZnCl2 KCl-MgCl2-NaCI, MgCl2 NaCl,
etc. are also used for the temperature range of 200-
450°C.
100 Solar Energy Storage 9/22/2014
102. Electrical Storage
Capacitor storage
Inductor storage
Battery storage: stored electrochemically, and
later regained as electrical energy. Battery
storage system may be included under chemical
energy storage also.
102 Solar Energy Storage 9/22/2014
105. Chemical Storage
1. Storage in the form of fuel:
• storage battery in which the reactant is generated by a
photochemical reaction brought about by solar radiation. The
battery is charged photo -chemically and discharged
electrically whenever needed.
• It is also possible to electrolyze water with solar generated
electrical energy, store O2 and H2 and recombine in a fuel cell
to regain electrical energy
• Solar energy could be used by the anaerobic fermentation
• Photosynthesis has been mentioned as a method of solar
energy conversion
• The carbohydrates are stable at room temperature; but at
high temperature the reaction is reversed, releasing the
stored energy in thermal form.
105 Solar Energy Storage 9/22/2014
106. 2. Thermo-chemical energy storage (Reversible
chemical reactions).
Thermo-chemical storage
systems are suitable for medium or high
temperature applications only. For storage of
high temperature heat, some reversible
chemical reactions appear to be very attractive.
Advantages of thermo-chemical storage include
high energy density storage at ambient
temperatures for long periods without thermal
losses and potential for heat pumping and
energy transport over long distances.
106 Solar Energy Storage 9/22/2014
109. Mechanical Energy Storage
(i) Pumped hydroelectric
storage:
the water is allowed to flow
back down through a
hydraulic turbine which
drives an electric
generator. The overall
efficiency of the pumped
storage, that is, the
percentage or the
electrical energy used to
pump the water is
recovered as electrical
energy is about 70%.
109 Solar Energy Storage 9/22/2014
110. (ii) Compressed Air
Storage.
when the wind is not
blowing the energy
stored in the air could
be utilized to drive an
air turbine, whose shaft
would then drive a
generator
(iii) Flywheel storage.
The energy is stored as
kinetic energy, most of
which can be electrically
regained when the
flywheel is run as a
generator
110 Solar Energy Storage 9/22/2014
111. Electromagnetic energy
storage
Electromagnetic energy storage requires the use of
super conducting materials. These materials
(metals and alloys) suddenly lose essentially all
resistance to the flow of electricity when cooled
below a certain very low temperature. If
maintained below this temperature a super
conducting metal (or alloy) can carry strong
electric currents with little or no loss.
111 Solar Energy Storage 9/22/2014
112. Solar Pond
Introduction: A natural or artificial body of water
for collecting and absorbing solar radiation energy
and storing it as heat. Thus a solar pond combines
solar energy collection and sensible heat storage.
112 Solar Energy Storage 9/22/2014
113. Features
The simplest type of solar pond is very shallow, about 5 - 10
cm deep, with a radiation absorbing (e.g., black plastic)
bottom.
All the pond water can become hot enough for use in space
heating and agricultural and other processes.
the water soon acquires a fairly uniform temperature.
Solar ponds promise an economical way over flat-plate
collectors and energy storage by employing a mass of water
for both collection and storage of solar energy.
The energy is stored in low grade (60 to 100ºC)
Salt-gradient solar pond or nonconvecting solar pond' are
also often used, as to distinguish these ponds from 'shallow
solar pond'.
113 Solar Energy Storage 9/22/2014
116. The salt used in a solar pond for creating
density gradient should have the following
characteristics:
It must have a high value of solubility to allow high solution
densities.
The solubility should not vary appreciably with temperature.
Its solution must be adequately transparent to solar radiation.
It must be environmentally benign, safe to handle the ground
water.
It must be available in abundance near site so that its total
delivered cost is low, and
It must be inexpensive.
116 Solar Energy Storage 9/22/2014
117. Extraction of Thermal Energy
The process of heat extraction, accomplished by
hot brine with drawn and cool brine return in a
laminar flow.
Thermal energy from solar pond is used to drive a
Rankine cycle heat engine. Hot water from the
bottom level of the pond is pumped to the
evaporator.
117 Solar Energy Storage 9/22/2014
119. Applications of Solar Ponds
1. Heating and
Cooling of
Buildings.
Because of the large
heat storage
capability in the lower
convective zone of the
solar pond, it has
ideal use for heating
even at high latitude
stations and for
several cloudy days.
2. Production of
Power.
A solar pond can be used
to generate electricity by
driving a thermo-electric
device or an organic
Rankine cycle engine-a
turbine powered by
evaporating an organic
fluid with a low boiling
point.
119 Solar Energy Storage 9/22/2014
120. 3. Industrial
Process Heat.
Industrial
process heat is the
thermal energy used
directly in the
preparation and of
treatment of materials
and goods
manufactured by
industry.
4. Desalination.
The low cost thermal
energy can used to
desalt or otherwise
purify water for
drinking or irrigation.
120 Solar Energy Storage 9/22/2014
121. 5. Heating animal
housing and drying
crops on farms.
6. Heat for biomass
conversion.
Site built solar
ponds could provide
heat to convert
biomass to alcohol
or methane
121 Solar Energy Storage 9/22/2014
127. Introduction
• Solar energy is a time dependent and intermittent
energy resource
• The need for energy storage of some kind is
almost immediate evident for a solar electric
system.
• solar energy is most available will rarely coincide
exactly with the demand for electrical energy
• high insolation times could be used to provide a
continuous electrical output or thermal output
127 Solar Energy Storage 9/22/2014
128. Storage of solar energy in a solar
system may:
• Permit solar energy to be captured when
insolation is highest
• it possible to deliver electrical load power demand
during times
• Be located close to the load
• Improve the reliability of the solar thermal as well
as solar electric system
• Permit a better match between the solar energy
input and the load demand output
128 Solar Energy Storage 9/22/2014
129. Optimum capacity of an energy
storage system
• The expected time dependence of solar radiation
availability.
• The nature of load to be expected on the process.
• The degree of reliability needed for the process.
• The manner in which auxiliary energy is supplied.
• The size of the solar thermal power system or solar-electric
generator.
• The cost per kWh of the stored energy.
• The permissible capital cost allocated to storage.
• Environmental and safety considerations.
• An economic analysis that determines how much of the
total usually annual loads should be carried by solar and
how much by auxiliary energy sources. 129 Solar Energy Storage 9/22/2014
131. Thermal Storage
Energy can be stored by
heating, melting or
vaporization of material,
and the energy
becomes available as
heat.
I. Sensible heat
storage
II. Latent heat
131 Solar Energy Storage 9/22/2014
132. I. (A ) water storage
The most common heat transfer fluid for a solar
system is water, and the easiest way to store thermal
energy is by storing the water directly in a well
insulated tank.
Characteristics for storage medium
• It is an inexpensive, readily available and useful
material to store sensible heat.
• It has high thermal storage capacity.
• Energy addition and removal from this type of
storage is done by medium itself. thus
eliminating any temperature drop between
transport fluid and storage medium.
132• PSuolmar Epneirngyg Stocraogest is small 9/22/2014
133. I. (B) Packed Bed Exchanger
Storage
Sensible heat storage with air as the energy transport
mechanism, rock, gravel, or crushed stone in a bin has the
advantage of providing a large, cheap heat transfer
surface.
Rock does have the following advantages over water
• Rock is more easily contained than water.
• Rock acts as its own heat exchanger, which reduces total
system cost.
• It can be easily used for thermal storage at high
temperatures, much higher than 100°C; storage at high
temperature where water can not be used in liquid form
without an experience, pressurized storage tank.
• The heat transfer coefficient between the air and solid is
high.
• The cost of storage material is low.
• The conductivity of the bed is low when air flow is not
133 Solar Energy Storage 9/22/2014
135. II. (B) Latent heat storage
Materials that undergo a change of phase in a suitable temperature range may be useful for energy
storage
• The phase change must be accompanied by high latent heat
• The phase change must be reversible over a very large number of cycles without degradation.
• The phase change must occur with limited super cooling.
• Means must be available to contain the material and transfer heat into it and out of it.
• The cost of materials and its containers must be reasonable.
• Its phase change must occur close to its actual melting temperature.
• The phase change must have a high latent heat effect, that is, it must store large quantities of
heat.
• The material must be available in large quantities.
• The preparation of the phase changing material for use must be relatively simple.
• The material must be harmless (non-toxic, non-inflammable, non-combustible, non-corrosive).
• A small volume change during the phase change.
• The material should have high thermal conductivity in both the phases.
135 Solar Energy Storage 9/22/2014
136. Materials for phase change energy
storage.
• Glauber's salt (Na2S04.10 H20), water, Fe(N03)2 .6
H20, and salt Eutectics
• Organic compound or substances serve as heat
storage materials Paraffin and fatty acids
• Refractory materials (MgO, Al203, SiO2) are also
suitable for high temperature sensible heat storage
in addition to Rock or pebble bed storage. Some
thermal storage materials such as ZnCI2, Na(OH)3,
NaOH, KOH-ZnCl2 KCl-MgCl2-NaCI, MgCl2 NaCl,
etc. are also used for the temperature range of 200-
450°C.
136 Solar Energy Storage 9/22/2014
138. Electrical Storage
Capacitor storage
Inductor storage
Battery storage: stored electrochemically, and
later regained as electrical energy. Battery
storage system may be included under chemical
energy storage also.
138 Solar Energy Storage 9/22/2014
141. Chemical Storage
1. Storage in the form of fuel:
• storage battery in which the reactant is generated by a
photochemical reaction brought about by solar radiation. The
battery is charged photo -chemically and discharged
electrically whenever needed.
• It is also possible to electrolyze water with solar generated
electrical energy, store O2 and H2 and recombine in a fuel cell
to regain electrical energy
• Solar energy could be used by the anaerobic fermentation
• Photosynthesis has been mentioned as a method of solar
energy conversion
• The carbohydrates are stable at room temperature; but at
high temperature the reaction is reversed, releasing the
stored energy in thermal form.
141 Solar Energy Storage 9/22/2014
142. 2. Thermo-chemical energy storage (Reversible
chemical reactions).
Thermo-chemical storage
systems are suitable for medium or high
temperature applications only. For storage of
high temperature heat, some reversible
chemical reactions appear to be very attractive.
Advantages of thermo-chemical storage include
high energy density storage at ambient
temperatures for long periods without thermal
losses and potential for heat pumping and
energy transport over long distances.
142 Solar Energy Storage 9/22/2014
145. Mechanical Energy Storage
(i) Pumped hydroelectric
storage:
the water is allowed to flow
back down through a
hydraulic turbine which
drives an electric
generator. The overall
efficiency of the pumped
storage, that is, the
percentage or the
electrical energy used to
pump the water is
recovered as electrical
energy is about 70%.
145 Solar Energy Storage 9/22/2014
146. (ii) Compressed Air
Storage.
when the wind is not
blowing the energy
stored in the air could
be utilized to drive an
air turbine, whose shaft
would then drive a
generator
(iii) Flywheel storage.
The energy is stored as
kinetic energy, most of
which can be electrically
regained when the
flywheel is run as a
generator
146 Solar Energy Storage 9/22/2014
147. Electromagnetic energy
storage
Electromagnetic energy storage requires the use of
super conducting materials. These materials
(metals and alloys) suddenly lose essentially all
resistance to the flow of electricity when cooled
below a certain very low temperature. If
maintained below this temperature a super
conducting metal (or alloy) can carry strong
electric currents with little or no loss.
147 Solar Energy Storage 9/22/2014
148. Solar Pond
Introduction: A natural or artificial body of water
for collecting and absorbing solar radiation energy
and storing it as heat. Thus a solar pond combines
solar energy collection and sensible heat storage.
148 Solar Energy Storage 9/22/2014
149. Features
The simplest type of solar pond is very shallow, about 5 - 10
cm deep, with a radiation absorbing (e.g., black plastic)
bottom.
All the pond water can become hot enough for use in space
heating and agricultural and other processes.
the water soon acquires a fairly uniform temperature.
Solar ponds promise an economical way over flat-plate
collectors and energy storage by employing a mass of water
for both collection and storage of solar energy.
The energy is stored in low grade (60 to 100ºC)
Salt-gradient solar pond or nonconvecting solar pond' are
also often used, as to distinguish these ponds from 'shallow
solar pond'.
149 Solar Energy Storage 9/22/2014
152. The salt used in a solar pond for creating
density gradient should have the following
characteristics:
It must have a high value of solubility to allow high solution
densities.
The solubility should not vary appreciably with temperature.
Its solution must be adequately transparent to solar radiation.
It must be environmentally benign, safe to handle the ground
water.
It must be available in abundance near site so that its total
delivered cost is low, and
It must be inexpensive.
152 Solar Energy Storage 9/22/2014
153. Extraction of Thermal Energy
The process of heat extraction, accomplished by
hot brine with drawn and cool brine return in a
laminar flow.
Thermal energy from solar pond is used to drive a
Rankine cycle heat engine. Hot water from the
bottom level of the pond is pumped to the
evaporator.
153 Solar Energy Storage 9/22/2014
155. Applications of Solar Ponds
1. Heating and
Cooling of
Buildings.
Because of the large
heat storage
capability in the lower
convective zone of the
solar pond, it has
ideal use for heating
even at high latitude
stations and for
several cloudy days.
2. Production of
Power.
A solar pond can be used
to generate electricity by
driving a thermo-electric
device or an organic
Rankine cycle engine-a
turbine powered by
evaporating an organic
fluid with a low boiling
point.
155 Solar Energy Storage 9/22/2014
156. 3. Industrial
Process Heat.
Industrial
process heat is the
thermal energy used
directly in the
preparation and of
treatment of materials
and goods
manufactured by
industry.
4. Desalination.
The low cost thermal
energy can used to
desalt or otherwise
purify water for
drinking or irrigation.
156 Solar Energy Storage 9/22/2014
157. 5. Heating animal
housing and drying
crops on farms.
6. Heat for biomass
conversion.
Site built solar
ponds could provide
heat to convert
biomass to alcohol
or methane
157 Solar Energy Storage 9/22/2014
163. Introduction
Three general categories:
(a) Direct Thermal Application make direct use of heat, resulting from the absorption of
solar radiation, for space heating (and cooling) of residences and other building, so
provide hot water service for such buildings, and to supply heat for agricultural
industrial, and other processes that require only moderate temperatures.
(b) Solar Electric Applications are those in which solar energy is converted directly or
indirectly into electrical energy. General conversion methods being investigated are
:
I. Solar thermal methods involve production of high temperatures, such as are
required to boil water or other working fluid for operating turbines which drive
electric generators. These are considered under solar thermal electric conversion.
II. Photovoltaic Methods make use of devices (Solar Cells) to convert solar energy
directly into electrical energy without machinery.
III. Wind Energy is the form of solar energy that can be converted into mechanical
(rotational) energy and hence into electrical energy by means of a generator. This
is indirect use of solar energy to generate electricity.
IV. Ocean thermal energy conversion depends on the difference in temperature
between solar heated surface water and cold deep ocean water to operate a vapor
expansion turbine and electric generator. This is indirect use of solar energy.
(C) Energy from Biomass and Bio-gas, refers to the conversion into clean fuels or
other energy related product of organic matter derived directly or indirectly from
plants which use solar energy to grow.
163 Application of Solar Energy 9/22/2014
164. Direct solar energy applications
are:
(1) Solar water heating.
(2) Space heating.
(3) Space cooling.
(4) Solar energy: Thermal electric conversion.
(5) Solar energy: Photovoltaic electric conversion.
(6) Solar distillation.
(7) Solar pumping.
(8) Agriculture and industrial process heat.
(9) Solar furnace.
(10) Solar cooking.
(11) Solar production of hydrogen, and
(12) Solar green houses.
164 Application of Solar Energy 9/22/2014
165. (1) Solar water heating.
The basic elements of a solar water heater are:
I. Flat plate collector.
II. Storage tank.
III. Circulation system and auxiliary heating
system.
IV. Control of the system.
165 Application of Solar Energy 9/22/2014
166. Some typical and commercial designs of
solar water heaters are:
(I) Natural circulation solar water heater
(pressurized).
166 Application of Solar Energy 9/22/2014
167. (ii) Natural circulation solar water heater (non-pressurized).
167 Application of Solar Energy 9/22/2014
172. (2) Space-Heating (or Solar heating of Building)
passive systems: in which solar radiation is collected by
some element of the structure itself, or admitted
directly into building through large, south facing
windows.
Active systems: which generally consists of
(a) separate solar collectors, which may heat
either water or air,
(b) storage devices which can accumulate the
collected energy for use at nights and during
inclement days, and,
(c) a back up system to provide heat for
protected periods of bad weather.
172 Application of Solar Energy 9/22/2014
173. Solar Heating Systems (A) Passive Heating
Systems.
If a building is designed properly:
(i) It will function as a solar collector, collecting heat when the sun is shining
and storing it for later use.
(ii) The building will function as a solar store house. It must store the heat for
cool times when the sun is not shining, and store the cool for warm or hot
periods when the sun is shining. Buildings which are made of heavy
materials such as stone or concrete do this most effectively.
(iii) Building will function as a good heat trap. It must make good use of the
heat (or cool) and let it escape only very slowly. This is done primarily by
reducing the heat loss of the building through the use of insulation,
reduction of infiltration and storm windows.
173 Application of Solar Energy 9/22/2014
174. The basic design principles of passive solar space-heating
systems, that is, without mechanical
components, fall into the following five general
categories:
I. Direct gain
II. Thermal storage wall: Dr. Felix France
III. Attached sun space
IV. Roof storage
V. Convective loop.
174 Application of Solar Energy 9/22/2014
180. Advantages
I. In case of water heating, a common
heat transfer and storage medium,
water is used, this avoids
temperature drop during transfer of
energy into and out of the storage.
II. It requires relatively smaller
storage volume.
III. It can be easily adopted to supply
of energy to absorption air
conditioners, and Relatively low
energy requirements for pumping
of the heat transfer fluid.
Disadvantages
I. Solar water heating system will
probably operate at lower water
temperature than conventional
water systems and thus require
additional heat transfer area or
equivalent means to transfer heat
into building.
II. Water heaters may also operate at
excessively high temperatures
(particularly in spring and fall) and
means must be provided to remove
energy and avoid boiling and
pressure build up.
III. Collector storage has to be
designed for overheating during the
period of no energy level.
IV. Care has to be taken to avoid
corrosion problems.
180 Application of Solar Energy 9/22/2014
181. Basic Hot air System
181 Application of Solar Energy 9/22/2014
182. Advantages
I. There is no problem with
freezing in the collectors.
II. Corrosion problems are
minimized.
III. Conventional control
equipment for air heating is
already available and can
be readily used.
IV. Problems of designing for
over heating during periods
of no energy removal are
minimized, and,
V. The working fluid is air and
the warm air heating
systems are ill common
use.
Disadvantages
I. Relatively higher power
costs for pumping air
through the storage
medium.
II. Relatively large volumes
of storage units.
III. Difficulty of adding
absorption air
conditioners to the
system.
182 Application of Solar Energy 9/22/2014
186. (4) Solar energy: Thermal
electric conversion.
I. Low temperature cycles using flat plate collector or
solar cycle.
II. Concentrating collectors for medium and high
temperature cycle.
III. Power tower concept or central receiver system.
IV. Distributed collector system.
186 Application of Solar Energy 9/22/2014
196. Solar pumping
The basic system consists of the following
components :
1. The solar collectors, may be
(a) Flat plate collectors or solar pond
(b) Stationary concentrator (CPC)
(c) Sun-tracking concentrators, (cylindrical parabolic
trough concentrator or heliostats).
2.The heat transport system.
3.Boiler or Heat Exchanger.
196 Application of Solar Energy 9/22/2014
197. 4. Heat engine, it may be
(a) Rankine engine
(b) Stirling hot gas engine
(c) Brayton cycle gas turbine
(d) Rotary piston engine.
5. Condenser.
6. Pump, it may be
(a) Reciprocating pump
(b) Centrifugal pump
(c) Diaphragm pump
(d) Rotary pump.
Reciprocating engine
Vapor turbine
197 Application of Solar Energy 9/22/2014
198. The collector area to a large extend is determined by the overall efficiency of the system
198 Application of Solar Energy 9/22/2014
202. Agriculture and industrial process
heat
Solar energy for thermal applications in industries has proved
to be economically viable at present for temperatures less than
100°C. With intensive development in the area of fixed and
tracking concentrators, temperatures 0 to 300°C will be feasible.
The technology is expected to be matured in near future. In the
present energy context, it is desirable to provide thermal energy
below 300°C from solar
202 Application of Solar Energy 9/22/2014
203. These applications of solar energy may be considered in
three general categories, according to the temperature
range within which the heat is supplied.
1. Low temperatures below 100°C: based on the use
or flat-plate collectors, with either air or water as the
heat transport medium.
Among the potential applications of low temperature heat in
the agriculture are the following:
Heating and cooling of commercial green houses.
Space heating of livestock shelters, dairy facilities and
poultry houses.
Curing of bricks, plaster board etc. Drying grain,
soybeans, peanut pods, fruits, tobacco, onions and kiln
(Lumber) Solar energy can also be used to convert salty
water (or other impure water) into potable. water by
203 diAsptpilliclaatitoino onf S.olar Energy 9/22/2014
204. 2.Intermediate temperatures 100 to 175°C:
Laundries
Fabric drying
Textile dyeing
Food processing and can washing
Kraft pulping (in paper industries)
Laminating and drying glass fiber
Drying and baking in automobile industries
Pickling (in steel industries) etc.
3.High temperatures above 175°C:
Steam at temperatures above 175°C is used extensively in
Industry particularly in the generation of electric power.
204 Application of Solar Energy 9/22/2014
205. The several advantages of industrial applications over
residential or commercial ones are :
Industrial loads are mostly on continuous basis
throughout the year.
Industrial plants have maintenance crew, or in small
plants ,killed people, who can attend to smooth operation
of solar systems.
Total quantum of energy replaced by solar is significantly
more causing higher reduction in oil imports and
diversion of coal for high temperature tasks.
205 Application of Solar Energy 9/22/2014
206. limitations
Intermittent availability of solar energy.
Instantaneous area. In all the cases roof area may not be
adequate to accommodate required collector area. Additional
costly land may have to be used. In some cases, roof have east
west slopping, instead of north glazing type, rending placement
of collectors to be costly and unaesthetic.
Industrial effluents can be harmful to the transparent covers and
reflecting surfaces.
Through pay back period has come down to 3-5 years (hot water
and air only), high initial capital investment is a major
impediments.
206 Application of Solar Energy 9/22/2014
207. Solar Furnace
A solar furnace is an instrument to get high temperatures by
concentrating solar radiations onto a specimen. Solar furnaces have
long been used for scientific investigations.
Applications: Used for high temperature application in chemical reactions
French scientist Lavoisier used 1774with a lens as tall as man
German scientist Strauble devised1921a solar furnace composed of a
paraboloidal concentrator and a lens.
Specific points:
The first large solar furnace with a thermal power of 45 kW was completed in
France in 1952.
A similar furnace with a power of about 35 kW, was constructed for the U.S.
Army at Natick, Massachusetts, in 1958.
The world's largest solar furnace, with a design thermal pee of 1000 kW,
commenced operation at Odeillo in the French Pyrenees in 1973 consisting
63 heliostats having an area 45 sq. m.
207 Application of Solar Energy 9/22/2014
209. Uses of solar furnace
The solar furnace is an excellent means for studying properties of
ceramics at high temperatures above the range ordinarily measured
in the laboratory with flames and electric currents.
Physical measurements include melting points, phase changes,
specific heat, thermal expansion, thermal conductance, magnetic
susceptibility and thermionic emission.
Several useful metallurgical and chemical operations have been
carried out at high temperatures in the solar furnaces.
The melting and sintering of temperature ceramics such as zirconia
is easily accomplished.
Direct high temperature production or zirconia from zircon and alkali,
beryllia from beryl, and tungsten from wolframite is carried out in
solar furnaces.
Purification of a refractory (Al203) by sublimation at high temperatures
also has been carried out
209 Application of Solar Energy 9/22/2014
210. Advantages and Limitations of a Solar
Furnace
Advantages
In a solar furnace heating is carried out without any contamination
and temperature is easily controlled by changing the position of the
material in focus.
It gives an extremely high temperature.
It provides very rapid heating and cooling.
Various property measurements are possible on an open specimen.
Contamination by ions does not occur in fusion which might happen
in the case of plasma or oxy hydrogen flame.
Proper desirable atmosphere can be provided to the specimen
Limitations
Its use is limited to sunny days, and to 4-5 hours only (maximum
bright sun shine hours), and
high cost.
210 Application of Solar Energy 9/22/2014
213. Solar Cooking
The first solar cooker was developed in the year
1945 by Mr. M.K Ghosh of Jamshedpur a freedom
fighter.
Later in 1953 NPL of India developed a parabolic
solar cooker
Basically there are three designs of solar cooker:
Flat plate box type solar cooker with or without
reflector
Multi reflector type solar oven and
Parabolic disc concentrator type solar cooker.
213 Application of Solar Energy 9/22/2014
214. Flat plate box type design is the
simplest of all the designs.
Maximum no load temperature with
a single reflector reaches up to
l50°C.
In multi reflector oven four square
or triangular or rectangular
reflectors are mounted on the oven
body. They all reflect the solar
radiations into the cooking zone in
which cooking utensils are placed.
Temperature obtained is of the
order of 200°C. The maximum
temperature can reach to 250°C
Parabolic disc concentrator type
solar cooker, temperatures of the
order of 450°C can be obtained in
which solar radiations are
concentrated onto a focal point
214 Application of Solar Energy 9/22/2014
215. Merits of a solar cooker:
No attention is needed
during cooking as in other
devices.
No fuel is required.
Negligible maintenance
cost.
No pollution.
Vitamins of the food are
not destroyed and food
cooked is nutritive and
delicious with natural
taste. .
No problem of charring of
food and no over flowing.
215 Application of Solar Energy 9/22/2014
216. Limitations of a solar cooker
One has to cook according to the sun shine, the menu
has to be preplanned.
One can not cook at short notice and food can not be
cooked in the night or during cloudy days.
It takes comparatively more time.
Chapaties are not cooked because high temperature for
baking is required and also needs manupulation at the
time of baking. Box Type Solar Over (Multi reflector Type)
216 Application of Solar Energy 9/22/2014
220. Solar Green Houses
Definition:
1. A green house is a growth chamber which offers the
possibilities of year round plant production. These are
effective solar collectors. These can also be geared to the
needs of the rural, urban and suburban populations. A green
house attached to a residence creates a pleasant
improvement in the physical and mental environment of its
occupants; designed in a truly passive solar collection
manner with a well-applied heat store, this type of solar
collector (or power house) may also provide much of the
required winter heat. Solar green houses are relatively easy
to build with simple technology and low cost materials.
2. Green houses provide crop cultivation under controlled
environment. A green house is a structure covered with
transparent material that utilizes solar radiant energy to grow
plants and may have beating, cooling and ventilating
equipments for temperature control.
220 Application of Solar Energy 9/22/2014
221. The plant environment refers :
Soil temperature
Air temperature
Air humidity
Soil moisture
Light
Air composition
Root medium composition
Protection from plant enemies
Exposure to rain
Hail storm etc.
221 Application of Solar Energy 9/22/2014
222. Advantages of Green houses
A source of inexpensive, good quality food that
one grows one
A source of additional heat (temperature control)
for the house attached to it,
A source of moderator for the humidity (humidity
control) in the house.
222 Application of Solar Energy 9/22/2014
223. Types of Green Houses
Attached green house: which may be joined onto
almost any suitable building structure.
Porch type green houses: which may be designed as
the entrance to a house, factory or office.
Free standing green houses: which may be situated
on any convenient patch or piece of waste ground.
Pit type green houses: which are usually employed
on differing level or sloping land scapes, and for the
purpose of heat retention.
Cold frame type of green houses: which are simply
hot-bed, or plant facing frames equipped with a
sloping roof.
223 Application of Solar Energy 9/22/2014
233. Solar Production of Hydrogen
Methods of producing hydrogen from solar energy
There are four basic methods:
1. Direct thermal,
2. Thermo chemical,
3. Electrolytic, and
4. Photolytic.
233 Application of Solar Energy 9/22/2014
234. Direct thermal
2 1 2 2 2 3 2 H O heatx H O x H x O
Water is heated up to 3000o C
X1, X2 and X3 are mole fractions
Water should be decomposed at
fairly high temperature (for
equilibrium decomposition)
combined with a reduced
pressure. The energy for
dissociation of hydrogen can be
obtained from the solar energy.
An optical system which
collects solar radiation and con-centrates
Advantages of this
methods are :
1. High thermal efficiency,
2. Negligible environmental
impact, and
3. Intermediary chemicals
are not required.
4. Because of high
temperature
requirements, it requires
extensive research for
commercial application.
234 Application of Solar Energy 9/22/2014
236. Electrolyte
The cell consists of electrodes dipped in an electrolyte and connected to a d.c.
supply. Water with some conducting chemicals is used as an electrolyte.
When sufficient potential is applied between the electrodes to cause a
current to flow, oxygen is liberated at the anode and hydrogen at the
cathode.
In this method, the solar energy is first converted to d.c. electric
power, then hydrogen through electrolysis. Hence it is especially suited for
coupling with ocean, thermal, wind, hydro and photovoltaic forms of solar
energy since in these cases solar energy is converted to electricity.
236 Application of Solar Energy 9/22/2014
237. Photolytic
Photons in the ultraviolet region of radiation spectrum passes the
energies needed for the direct photolysis of water, in the presence
of catalyst.
Note that photo catalyst X is not consumed, but is regenerated and
available for reuse. Biological photo catalysts are also in existence.
Among the four basic methods for producing hydrogen from solar energy.
the direct thermal method has the potential of highest thermal efficiency.
followed by thermo chemical. electrolyte and photolytic method.
237 Application of Solar Energy 9/22/2014
238. Schematic representation of the two-step water-splitting cycle using
the
Zn/ZnO redox system for the solar production of hydrogen
238 Application of Solar Energy 9/22/2014
239. Solar Hydrogen from Landfill Gas
Reaction 2
CO + H2O H2 + CO2 ΔHf = 40.6 kJ/mole
239 Application of Solar Energy 9/22/2014
240. Biohybrid catalysts for solar hydrogen production
Components for coupling solar-driven, photosynthetic water oxidation to hydrogen (H2) production in
photobiological systems are shown on the left. Solar-driven water splitting by the photosynthetic apparatus generates
charge that is transferred to a mobile charge carrier, ferredoxin, and ultimately to hydrogenase for catalytic H2
production. On the right, components of an artificial, solar biohybrid H2 production device. If used as a cathode in a
solar capture device (black arrows), charge generation and transfer from the solar device to the cathode drives
catalytic H2 production. If the biohybrid is composed of semiconducting materials of appropriate energetics, the
material itself generates the charge for catalytic H2 production (red arrows). e–: Photogenerated charge. D, D+:
Reduced, oxidized state, respectively, of a sacrificial dono molecule.
240 Application of Solar Energy 9/22/2014
241. Diagram shows that
photovoltaic material
behind the film converts
the rest of the solar
spectrum into electricity,
supplying the device with
extra voltage to boost
hydrogen production.
BUBBLING WITH
HYDROGEN. In this
tandem cell, a
nanostructured metal-oxide
film absorbs the
sun's ultraviolet and blue
light to split water.
241 Application of Solar Energy 9/22/2014
242. CO2 Capture from Air and Co-production
of Hydrogen
242 Application of Solar Energy 9/22/2014
249. Geothermal Energy
Introduction - Applications - Utilization of Geothermal
Energy Geothermal Energy Resources - Characteristics
of Geothermal Resources - Geothermal Gradients -
Non-uniform Geothermal Gradients Hydro Geothermal
Resources - Geopressure Geothermal Resources -
Geopressure Energy Reserves - Hot Dry Rock
Geothermal Resources Merits and Demerits of Petro-
Geothermal Energy Plants - Fracture Cavity by High
Pressure Water – Fracture Cavity by Chemical
Explosives - Geothermal Fluids for Electrical Power
Plants - Geothermal Electrical Power Plants.
249 Geothermal Energy 9/22/2014
250. Introduction
The thermal energy contained in the interior of the
earth is called the geothermal energy
250 Geothermal Energy 9/22/2014
251. IMPORTANT ASPECTS ABOUT THE GEOTHERMAL ENERGY
Characteristics Remarks
Form of energy Thermal energy in the form of hot water, steam, geothermal
brine, mixture of these fluids
Availability Generally available deep inside the earth at a depth more than
about 80 km. Hence, generally not Possible to extract
In a few locations in the world, deposits are at depths of 300 m
to 3000 m. Such locations are called the geothermal Fields.
Method of extraction Deep product.ion wells are drilled in the geothermal fields. The
hot steam/water/brine is extracted from the geothermal deposits
by the production wells, by
pumping or natural pressure.
Geothermal fluids Hot water.
Hot brine
Wet steam, Mixture of above.
251 Geothermal Energy 9/22/2014
252. Characteristics Remarks
Countries which have - Chile - New Zealand - EI Salvadir
known Geothermal - Philippines -Hungary - Indonesia
Resources. - Iceland -Turkey - Italy
- U.S.A. -Japan - U.S.5.R.
- Mexico
Application of - Hot water for baths, therapy
Geothermal Energy - District heating, space heating
- Hot water irrigation in cold countries
- Air conditioning
- Green house healing
- Process heat
- Minerals in geothermal fluid
- electrical power generation.
252 Geothermal Energy 9/22/2014
253. Engineering
criteria
for applications of
Geothermal hot
water.
Application
Temperature
(more than)
·C
Depth
(less than)
km
Discharge
(more
Than)
m3/day
Electrical power
generation by
steam water cycle
100·C 3km 10000
Electrical power
generation by
binary cycle
70°C 2.5 km 25000
District healing 70·C 2.5 km 1000
253 Geothermal Energy 9/22/2014
254. Range of Geothermal Power plant installed
capacity
- 5MW - 400MW
Average geothermal gradient - 30°C / 1000 m depth
Geothermal energy Released through
earth's crust
- 0.06W/m2
About 1/1000th of solar energy on earth's
surface
Total geothermal reserves in the earth - 4 x 1012 EJ
Renewable energy deposits available for
use in upper 3 km zone
- 4000 EJ
Rate at which the renewable can be tapped for
production of electricity
- 2 to 10 EJ/Yr.
Types of Geothermal energy deposits
- hydrothermal Hot water and steam, hot brine
- petrothermal Hot dry rock (HDR)
254 Geothermal Energy 9/22/2014
257. Until 1904, the use of naturally available geothermal
energy had been limited for the use of warm water
baths, therapeutic treatments etc. After 1904 the
geothermal energy is being used for many
electrical power generation and non-electrical
applications. The non-electrical applications
include
Space heating
Air-conditioning
Greenhouse heating
Process heat
Medical therapy
Mineral extraction
desalination plants
heating houses,
agricultural water,
aquaculture water
257 Geothermal Energy 9/22/2014
258. Applications of Geothermal Energy for Various Purposes
Utilization
Countries
Electrical Power
Production
Non-electrical
Applications
Chile
El Salvadore
Hungary
Iceland
Italy
Japan
Mexico
New Zealand
Philippines
Turkey
USA
USSR
France
258 Geothermal Energy 9/22/2014
259. Important criteria for engineering applications of
geothermal water are
Temperature of geothermal fluid, °C
Discharge rate, m3/day
Useful life of production well, years.
Depth of Aquifer (m)
Mineral Contents gram/m3
259 Geothermal Energy 9/22/2014
260. Engg. Criteria for resources for geothermal power
Type of power
Avg. Temp. of
geothermal fluid,
oC
Discharge of
production
well m3/day
Depth of drill
hole (m)
Mineral
content g/kg
Electrical power plant
with steam-water cycle
185 to 255 10,000 650 to 3000 3 to 20
Electrical power
generation with binary
fluid cycle
(Ammonia/water or
Hydrocarbon/water,
Freon/water)
70 to 150 25,000 500 to 2500 6 to40
260 Geothermal Energy 9/22/2014
261. Geothermal Energy Resources
Depth
increases
Temperature
increases
30°C per 1000 m (Geothermal
Gradient)
300°C geothermal fluid is available at
10 km depth
A few favorable geothermal deposits at relatively less depths (300 m to
3000 m)
There are two types of geothermal energy deposits
1. Hydro-geothermal energy resources hot
water and steam at relatively lesser depths (3000 m). Hot water,
hot brine and steam can be extracted from such deposits
261 Geothermal Energy 9/22/2014
262. 2. Petro-geothermal energy deposits (HDR)
The hot dry rocks at temperature around 200°C and depth about 2000
m form important deposits of geothermal energy.
Two types of wells are drilled in HDR sites. These are called
production wells and injection wells.
Water is pumped in through the injection well into the Hot
Dry Rock fracture. The injected water collects heat from the hot
dry rock and forms a deposit of hot water and steam in the
fracture within the rock.
Production well extracts the hot water and steam from the
geothermal deposits in the hot dry rock.
Petro Geothermal Energy Deposits may deliver mixture of hot
water and steam of temperatures up to about 200°C for several
decades
262 Geothermal Energy 9/22/2014
263. Cross section of the earth with geothermal energy deposits, various
types of rocks, volcanoes. furmoroles, hot springs etc.
263 Geothermal Energy 9/22/2014
265. When hot water and steam reach the surface, they can
form fumaroles, hot springs, mud pots and other
interesting phenomena.
265 Geothermal Energy 9/22/2014
266. When the rising hot water
and steam is trapped in
permeable and porous
rocks under a layer of
impermeable rock, it can
form a geothermal reservoir.
266 Geothermal Energy 9/22/2014
268. Origin of Geothermal Resources
The earth was originally a mass of hot liquids, gases and steam. As the
fluids cooled by loosing heat to the ,atmosphere, the outer solid
crust, oceans, lakes were formed. The average thickness of cooler
outer crust is about 30 km. Hot dry rocks, hot gases and liquids are
deposited in the region below average depth of 2800 km. The
magma (molten mass) in the temperature range of 1250°C to
1500°C. The centre of the earth is at temperature about 4500°C.
The earth is loosing heat slowly through the outer crust with average
energy loss of about 0.025 W/m2.
The earth's outer crust and internal rock formation is nonuniform. The
liquid magma in the upper mantle approaches earth's surface at
some points resulting in higher thermal gradients and higher heat
flows through surface of the earth.
268 Geothermal Energy 9/22/2014
269. 1. Average geothermal
gradient app. 30°C/IOOO m.
2. Theoretical increase in
boiling point of water with
increase in depth allowing
for decrease in density of
water at higher temperature.
3. Temperature of water in
vigorous upflowing spring.
4. Effect of impermeable rock.
5. Leaky spring which
discharge large quantities of
hot water.
269 Geothermal Energy 9/22/2014
270. Hydro-geothermal energy resources
The earth's surface have potential hydro geothermal resources in the form of
hot water, wet steam and mixture of hot water and steam of medium
temperatures (below 200°C).
The water gets heated and rises through defects in the solid impermeable
rocks and gets collected in the fractures within the permeable rocks. The
upper impermeable rock provides insulating covering to the hot water
deposits.
The hot water deposits without much steam content are called liquid
dominated hydro geothermal deposits. The temperature of water in such
deposits is usually in the range of IOO°C to 310°C.
When wells are drilled in the ground over such deposits, there are three
possibilities:
-The hot water and steam rises naturally through the production well (Geo-pressure
system).
- The hot water should be pumped up through the production well.
-Geothermal brine rises through the production well. The geothermal liquid having
270 Geothermal Energy 9/22/2014
high mineral content (calcium chloride, boron. clay, etc.) is called geothermal brine.
273. Reference data of a Geopressure hydrothermal aquifer and well
Aquifer,
Depth of reservoir(deposit) 3660 m
Radius of reservoir (deposit) 16 km
Initial pore pressure 680 kg/cm2
Thickness of stratrom 60 m
Rock porosity 20 %
Well diameter (I. D. of pipe ) 23 cm
Production Well
Well diameter (ID of pipe) 23 cm
Temperature of discharge 37 oC
Temperature at reservoir at surface 125 oC
273 Geothermal Energy 9/22/2014
276. 9/22/2014
Hot Dry Rock Geothermal Resources (Petro Geothermal
Resources)
The hard rock (igneous and crystalline rock)
surrounding the magma is at high
temperature. Water does not exist in the
surroundings and the heat exists in hot dry
rock (HDR). The known temperatures .of hot
rocks at useful depths up to 3000 m are
between 150°C and 290°C. The HDRs are
impermeable. HDR resources represents
highest (about 85%) of total extractable
geothermal energy deposits in the world.
Technique employed for thermal energy
extraction:
- To produce a large fracture (F) in the hot dry
crystalline rock.
- To drill production wells and injection wells
up to the fracture cavity.
- To pump in (inject) cold heat transport fluid
(generally water) into the cavity of the fracture
by means of injection wells.
- To pump up hot water and steam from
276 prodGuecotitohne rwmealll. Energy
277. The petro geothermal energy is extracted from Hot-Dry Rock (HRD) at
relatively medium depths (2500 m). Fracture cavity is produced inside
the rock by one of the following means.
- Fracture produced by high pressure water injected in existing fracture.
- Fracture produced by underground nuclear explosion or underground
chemical explosion.
- The fracture cavity created in the dry hard rock is typically of
-Conical chimney shape produced by explosive techniques, or
- Cylindrical disc shaped produced by high pressure hydraulic
techniques.
277 Geothermal Energy 9/22/2014
278. Reference data of Petro Geothermal (HDR) Fracture and Well
Depth of production well 2300 m
Depth of injection well 1450 m
Shape of fracture Vertical dish
Depth at bottom of fracture 2400 m
Depth at top of fracture 3300m
Diameter of fracture 900
Volume off fractured cavity 1.27 x 108 m3
Injection fluid pressure 110 kg/cm2
Injection fluid temperature 20 oC
Production fluid pressure 136 kg/cm2
Production fluid temperature 262oC
278 Geothermal Energy 9/22/2014
279. Merits and Demerits of Petro-Geothermal Energy
Power Plants
Merits
Operational flexibility
Water flow rate and temperature
may be selected by different
depths of production wells.
Large heat resources can be
tapped.
Several wells can be drilled in the
geothermal field to obtain high flow
rate essential for large power
plants,
Very long life of production wells
10 to 30 years or even more
Demerits
Leakage of injected water from the
artificial fracture cavities into
underground layers or rock.
High cost of fracture, drill wells etc.
Several mechanical,
thermodynamic, metallurgical,
economic
Studies are necessary before
finalizing the location of plant.
Wells are deep.
279 Geothermal Energy 9/22/2014
280. Types of Geothermal Fluids
Geothermal Fluid Type of Turbine, Cycle
Dry steam Steam- turbine cycle
Hot water temperature > 180°C Steam- turbine cycle
Hot water, temperature< 150°C Binary cycle
Hot brine (pressurised) Binary cycle
Hot brine (Flashed) Special Turbine:
- Impact turbine
- Screw expander
- Bladeless turbine
280 Geothermal Energy 9/22/2014
281. Geothermal Fluids for Electrical Power
Plants
The classification of Geothermal
Electrical Power Plant is based
on
- Type of Geothermal
Energy Resource
- Geothermal steam
- Geothermal brine
- Geothermal hot water
- Hot rock.
- Type of Thermodynamic
cycle
- Steam Turbine ... Cycle.
- Binary cycle
- Total flow concept.
Dry steam geothermal sources
are very rare. So far only three
such sources have been
located.
-The Geysers, USA
-Laderello, Italy
-Matusukawa. Japan.
281 Geothermal Energy 9/22/2014
286. Development of primary energy consumption in Iceland since 1940. The
impact of rising oil prices in the 1970s can be seen clearly
286 Geothermal Energy 9/22/2014
287. Sectoral share of utilization of geothermal energy in Iceland in 2005.
Direct application
287 Geothermal Energy 9/22/2014
291. The first modern geothermal power
plants were also built in Lardello,
Italy The first geothermal power
plants in the U.S. were built in
1962 at The Geysers dry steam
field, in northern California. It is
still the largest producing
geothermal field in the world.
291 Geothermal Energy 9/22/2014
292. Flash technology was invented
in New Zealand. Flash steam
plants are the most common,
since most reservoirs are hot
water reservoirs. This flash
steam plant is in East Mesa,
California.
292 Geothermal Energy 9/22/2014
300. Power Technology Expected Capacity
Factor (%)*
Nuclear 90
Geothermal 86 – 95
Biomass 83
Coal 71
Hydropower 30 – 35
Natural Gas Combustion
Turbine
30 – 35
Wind 25 – 40
Solar 25 – 33
(~60 with heat storage
capability)^
300 Geothermal Energy 9/22/2014
301. A short glimpse at geothermal power
Principle of EGS
system for
geothermal
power production
Drilling rig at the
European R&D
site Soultz-sous-
Forêts (F)
301 Geothermal Energy 9/22/2014
303. Geothermal Electric Power
Plants
Introduction - Historical Background - Classification and Types of
Geothermal Power Plants - Vapour Dominated (Steam)
Geothermal Electrical Power Plant - Schematic Diagram -
Thermodynamic cycle on T.S. Diagram - Number of
Geothermal Production Wells and Unit Rating - Liquid
Dominated (Hot Water) Geothermal Electric Power Plants:
Types and Choice - Liquid Dominated Flashed Steam
Geothermal Electric Power Plant - Schematic Diagram -
Thermodynamic Cycle, T.S. Diagram - Mass Flow and Power
per Well: Flashed Steam Geothermal Power Plant - Double
Flashed System: Liquid Dominated Geothermal Plant -
Thermodynamic Cycle on T.S. Diagram - Binary Cycle Liquid
Dominated Geothermal Power Plants - Working Fluids for
Binary Cycle Systems - Merits of Binary Cycle Geothermal
Power Plant Description of Heber Binary Project in California.
USA - Description of East Mesa Binary Cycle Geothermal
Power Plant - Liquid Dominated Total Flow Geothermal Power
Plant – Petro-thermal (Hot Dry Rock) Geothermal Energy
Power Plant - Hybrid Conventional and Geothermal Power
303 Geothermal Electric Power Plants 9/22/2014
304. Basic Aspects Regarding Various Types of Geothermal Power Plants
304 Geothermal Electric Power Plants 9/22/2014
306. The following aspects have decisive influence on
the rating and configuration of Geothermal Power
Plants.
Geothermal Fluid. Steam, hot water, brine.
Temperature and Pressure of the geothermal
fluid at the discharge point of the production well.
Total dissolved minerals and solids in the
geothermal fluid (g/kg).
Rate of discharge by production wells (mass flow
per well kg/hr).
306 Geothermal Electric Power Plants 9/22/2014
307. Growth of geothermal power plant installed capacity in the world.
307 Geothermal Electric Power Plants 9/22/2014