energy resources

1. NON-CONVENTIONAL ENERGY
RESOURCES
DEPARTMENT OF MECHANICAL ENGINEERING

2. CHAPTER 1
OVERVIEW OF POWER GENERATION
Energy is a key element of interaction between nature and
society and is crucial in achieving a high standard of living
This makes energy resources extremely significant for every
country in the world and is considered a key input for
economic development
Twin means of Ozone and global warming posed an
enormous challenge to mankind in realizing a transition to
fully sustainable energy systems
Past examples of transitions to a newly developed energy
system e.g. the change from wood to coal, and the
subsequent change from coal to oil and gas have shown that
such transition require many decades

3. Transitions do not occur by themselves are need to follow
strategies and formulate visions of the desired end result
One could adopt the three major energy strategies
1. Reduce the use of energy through efficiency improvement
2. Supply energy via renewable sources and
3. Cleaver use of remaining fossil fuel
According to the 2007 BP statistical review, oil constituted
around 37 percent of global energy consumption in 2006
followed by Coal (27 percent) and natural gas (24 percent)
Furthermore the transport and aviation sectors, the lifetime of
any modern economy, are still totally depending on oil where
no other fuels have been able to make progress
Around 98 percent of the energy used for road and air
transport is based on fuels derived from oil

4. Given the essential role of energy to world economic growth
and indeed to contemporary civilization, from transportation
to health care delivery and food production, and the huge
financial cost required to sustain timely provision of energy,
it is understandable why there is so much concern about
energy security
The energy literature and numerous statements by officials of
oil-producing and oil-consuming countries indicate that the
concept of energy security is elusive
Definitions of energy security range from uninterrupted oil
supplies to the physical security of energy facilities to
support for bio-fuels and renewable energy resources
Historically, experts and politicians referred to “Security of
oil supplies” as “energy security”

5. Only recently policy makers started worrying about the
security of natural gas
The current global energy security system has emerged
largely in response to the 1973 oil embargo
Since then, it has evolved slowly and is based on:
Coordination on sharing oil supplies and oil stocks in cases
of emergency and disruption, pursuing policies of energy
conservation and promoting efficiency measures, monitoring
and analyzing the oil market, increased transparency in the
oil market data and more recently, engaging in constructive
dialogue with oil producers
Unlike the 1970s when oil dominated the energy policy
debate, the concept of energy security has broadened to
include the security of other sources of energy such as gas
and electricity

6. In this respect, oil is by far the most tradable fuel and
therefore presents fewer problems in forms of security when
compared to other less tradable fuels
Energy security has also become intertwined with
environmental concerns which place restrictions on the
choice of future fuels
Despite these new aspects of energy society, oil still occupies
a central location in the policy debate
This is expected, although the importance of oil as a
percentage of GDP has declined in most developed countries
in the last thirty years but it still constitutes the worlds’ most
important source of energy

7. PROJECTED ENERGY DEMAND
Worldwide energy demand over the next 300 years is a
function of global population and average energy
consumption per capital
By projecting these two factors, it is possible to develop an
estimate of future total global energy consumption
Conventional notions of development strongly link
increasing economic development, increases standard of
living, and higher population densities
A modern trend in the developed world, however, is the
stabilization, or even reduction in population growth

8. Less developed nations have not yet experienced this slowing
of population growth and have generated national growth
rates as high as 4.5% annually from 2000-2005
In the medium scenario, the population in the developing
world increased from 4.9 billion to 7.7 billion by 2300, while
the developed world sees a population increase of only 1.2 to
1.3 billion
The United States’ told energy consumption is currently
among the highest in the world
As economies in China, India, South East Asia, Brazil,
Eastern Europe and Africa continue to grow, the world-wide
average energy consumption per capital will increase as
people seek to emulate energy intensive life styles, such as
that in the United States

9. Energy use increases fastest in the emerging economies,
including China and India
This is a function of both high population growth and an
increase in energy consumption per capita as the standard of
living improves

10. What are Fossil Fuels:
The term “fossil fuels” encompasses a spectrum of mineral
organic compounds extracted from the earth
They include coal, petroleum, shale soil, tar sands and natural
gas
Coal is always a solid, it can be hard or soft and high or low
in ash or sulfur
Petroleum is always a liquid and its appearance ranges from
a straw colored fluid similar to motor oil to a black tar like
material that must be heated before it will flow
Gas has various amounts of methane, ethane, ethylene,
propane, propylene, butane, I-butane, 2-butane, isobutene,
carbon dioxide, hydrogen sulfide, helium and nitrogen

11. The common thread is all fossil fuels contain hydrogen and
carbon that react with oxygen from the air to release energy
All fossil fuels produce carbon dioxide, a green house gas,
when burned and when there is insufficient air all fossil fuels
produces highly toxic carbon monoxide

12. Renewable Energy
 Energy is the key for economic growth of every nation moreover life blood for
civilization. Due to larger increase in population, the demand of energy is also increasing
day by day. To meet out this increasing demand of energy a rapid combustion of fossil
fuels is taking place
 This rapid combustion of fossil fuels causes fast depletion of natural energy reserves and
environmental degradation like acid rain, photo chemical smog, ozone depletion and
global warming
 In order to overcome this energy crisis and environmental pollution, a great need arises to
search new alternative sources of renewable energy
 There are many alternate renewable sources of energy which can be used in place of fossil
fuels like; solar energy, wind energy, geothermal energy, hydropower energy, biomass
energy

13. Solar Energy
 Solar energy is the most abundant source of energy on earth,
however, the abundance of solar irradiation is not equally
distributed over the earthy; the sunniest regions are located
around the equator, receiving some 300W/m2 on average
annually, which translates into about 7KW/m2 /day (NASA
Atmospheric Science Data centre 2005)
 Regions further away from the equator still receive enough solar
irradiation for applications exploiting solar thermal and photo
voltaic conversion techniques

14. One generally distinguishes three forms of solar conversion
technologies to produce the following:
1. Electricity (Photo voltaic)
2. Low temperature heat (Solar thermal)
3. High thermal heat (Solar thermal power plant)
The sun radiates energy in the form of electromagnetic wave
It is a clean, inexhaustible, universally available source of
renewable energy
The output of the sun is 2.8 × 1023 kw/year

15.  The energy reaching the earth is1.5 × 1018
kw/year
 Peak solar insolation (radiation) often coincides with peak day time
demand
 Radiation received on earth at noon 1 𝑘𝑤/𝑚2
 Solar power 178 billion Mw
 10,000 times the world demand
 Cost 20 crore/Mw where as coal 4 crore/Mw
Solar energy can be utilized directly in two ways:
 By collecting the radiation heat and using it in thermal system
 By collecting and converting it directly to electrical energy using a
photovoltaic system (solar photovoltaic)

16. Wind Energy
 The amount of energy available in wind energy is smaller than
available from direct solar energy, only part of the solar energy
reaching the atmosphere is converted into wind energy as a result of
solar – induced temperature difference on earth
 The rotation of the earth also contributes to wind speed and direction
 The global theoretical wind energy potential has been estimated to be
some 2% of the solar energy reaching the atmosphere (Hubbert, 1971)
 Mankind has used wind power for over 25 centuries. The oil crises in
the 1970s prompted large scale development of wind turbines for the
generation of electricity

17.  At that time, typical turbine size was about 30 KW, with a rotor
diameter of 10m
 The rapid growth in technology has led to present turbine size of
2-5 MW with rotor diameters and hub heights in excess of 100m
 The most common configuration now is the vertical axis, three-
bladed rotor turbine, with the rotor in the upwind position
 The continuous development of turbines has been going hand in
hand with improvements in control and power regulation systems
and conversion efficiencies that now are typically around 50%,
i.e. 85% of the Betz limit (European Wind Energy Association,
2003). Since the 1990s, Offshore wind power has been developed,
motivated by the higher and more predictable wind speeds at sea

18.  cumulative installed capacity in 2003 was about 40 GW with a growth of 30%
annually over the past five years (ibid)
 Turbine costs are around 750 $/KW leading to electricity price between 0.03 –
0.08 US $/KWL depending on the location-dependent wind speed (ibid)
 For determination of the technical potential, average monthly wind speeds are
used (New et al. 1999; Image team, 2001), the technical potential is the product
of the amount of full-load hours, i.e., the number of hours a wind turbine operates
at its rated power, and the wind turbine power density (MW/Km2 ) in suitable
areas
 For suitable areas a value of 4 MW/Km2 is taken, somewhat lower than current
practice in wind forms (Hoogwijk et al, 2004)
 High values are found in Canada, the USA, the former USSR, and Oceania,
totaling more than 70% of the global potential

20. Geothermal Energy
 Geothermal energy is obtained by extracting heat from water or rocks deep
under the ground
 It requires facilities located in a suitable geological setting
 The optimum sites are usually in mountainous country that is difficult to
develop and often far from the main energy market
 It is flexible in its output capability and can be turned up and down, or off and
on, with little difficulty
 The technology exists to drill geothermal wells a number of Kilometers deep,
but the cost of the well increases with depth
 As a result, practical geothermal sites require that there be high temperature
rocks and/or water within approximately 300 meters of the surface

21.  If the temperature of the site is high, the thermal energy can be used
for heating or generating electric
 Many sites have low temperatures suitable only for heating
buildings
 In most places the soil reaches a constant temperature between 18
and 20 degree at a depth of 5 to 10 meters
 If a large heat exchanger is buried at this depth than a heat pump can
use the thermal mass of the ground as an energy storage device
 In the winter heat is pumped out of the ground to heat the house
 This cools the soil, in summer heat is pumped back into the ground

22.  This cools the house in the hot weather
 In heat from pumped from the house for cooling is put back into the ground to warm
it for the next winter cycle
 The technique works but has not been shown to be useful for home heating under
most circumstances
 At number sites, the hot water produced by the well contains a high concentration of
dissolved mineral salts (brine) that cause operational and corrosion problems with the
equipment
 Disposal of the brine can present a difficult environmental protection challenge
 Despite these short comings, modest geothermal electric power plants are in operation
in New Zealand, Italy and in California, Iceland satisfies much of their domestic heat
requirements with hot water from low temperature geothermal sources

23.  Geothermal energy is currently produced in places where the geological conditions
are suitable
 Calpine Energy Inc. San Jose California currently operates 850 mega watts of
geothermal sources
 Italy and New Zealand has been successful in drilling a productive well, the 1500
meter deep well was drilled in the sulfur springs area of the Island
 This well produces a mixture of water and steam super heated to 300 degrees Celsius
 It has the potential for the generation of about 10 mega watts of electric power
 Unlike many other renewable energy sources, geothermal is very reliable and will
continue to be harvested at suitable sites

24. Hydropower Energy
 Hydropower is obtained by allowing water to fall through a turbine to turn a
shaft
 Hydropower and geothermal energy sources have a number of characteristic
in common
 Both require facilities located in a suitable geological setting
 Both are flexible in output capability and can be turned up and down or off
and can with little difficulty
 For hydropower, optimum sites are usually in mountainous country
 These sites are difficult to develop and often far from the main energy market
 On a worldwide basis, hydropower installations produce more energy than do
geothermal sources

25.  The United States hydropower facilities produce about 10 times more energy
than do geothermal facilities
 The requirements for a hydropower site are: a river with a reliable flow of
water, in a Canyon with high walls and a narrow spot at which a dam can be
built
 This site should be selected to provide a maximum difference in the height of
the water above and below the dam
 The Canyons walls must have sufficient strength to support a dam
 Large river flow produces more potential energy, higher the dam the less
water required to produce a specific amount of energy
 This leads to the ideal dam site for the production of hydropower as a
vigorous river flowing in a narrow Canyon with high rock walls

26.  In hydroelectric power plants the energy of water is utilized to drive the
turbine which, in turn, runs the generator to produce electricity
 Rain falling upon the earth’s surface has potential energy relative to the
oceans towards which it flows
 This energy is converted to the shaft work where the water falls
through an appreciable vertical distance
 Hydro or water power is important only next to thermal power
 Nearly 20 percent of the total power of the world is met by hydropower
stations
 There are some countries like Norway and Switzerland where the
hydropower forms almost the total installed capacity

27. Biomass Energy
 Out of above renewable source of energy biomass looks as one of the
most promising and viable alternatives because use of biomass provides
substantial benefits as for as the environment is concerned and it rank
4th as an energy resource, providing approximately 14% of the worlds
energy need
 Since a huge amount of agriculture waste is available in country like
India is creates problem of waste disposal
Utilization of biomass like agriculture waste, municipal waste, hospital
waste, etc. results in the following advantages
 Minimization of waste
 Additional power generation which reduces a considerable load on
fossil fuels power grade

28.  Reduced of pollution level in the atmosphere
 Biomass absorbs CO2 during growth and emits it during combustion hence it
is a CO2 neutral fuel
There are two approaches of utilization of biomass for power generation
 Direct combustion of biomass
 Biomass gasification
 The direct combustion of biomass provides a lower efficiency and a high
environmental impact, due to the increase of particulate matter and various,
unburned hydrocarbons
 A promising way to use biomass for power generation is through biomass
gasification which enhanced the overall efficiency of power production from
biomass from (15%-20%) to (35%-40%) at reduced environmental impact

29.  In the last few years, many researchers have focused on biomass gasification
using a gas turbine, steam turbine combined cycle plant with integral biomass
gasifier
Biomass Gasification
 Gasification is a waste to energy technology seems to be one of the best
options available because it requires minimum fuel processing provides power
at higher efficiency and emit least harmful pollutions after combustion of
syngas turbine
 Gasification is a thermo-chemical conversion technology that converts solid
biomass materials into a combustible gas called a producer gas or syngas
Syngas is a mixture of CO, H2, CH4, CO2, H2O and N2 and tars. Combustion, of
syngas depends on

30.  Fuel composition
 Gasifying medium
 Operating pressure and temperature
 Moisture contents of the fuel
Several types of gasifiers have been developed, most important types are
 Fixed bed gasifiers
 Fluidized bed gasifiers
 Entrained flow gasifiers
 Fluidized bed gasifiers are a more recent developed and takes the advantages
of excellent mixing characteristics and high reaction rates at temperature of
(800 0C- 1000 0C) and at pressure of 15-25 bars, depending on the operating
pressure ratio of the gas turbine

31. Fluidized bed gasifiers are named because the bed material
(biomass) moves like a fluid due to the levitation of biomass
by the air flow
The fluidization occurs when the pressure drop across the
gasification bed multiplied with the area of the bed