Lecture 2 Resources Power

8/12/2019 Lecture 2 Resources Power

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Energy Resources and

Electric PowerWeek 2

Copyright Faraz Hasan, FHNG, SKKU, 2014

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Energy Resources

Courtesy: Conserve Energy Future

Wood Coal Oil

Natural Gas

Nuclear Fuel

Renewables(Wind/Geothermal)

Evolution of energy resources.

We tend to fulfill our

energy needs by burning

fuel.

Trends are changing, we

are (gradually) moving

towards renewable energy.


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Petroleum


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Coal

Coal is sedimentary rock formed due to thedecomposition of plant tissues, and exudates that

have been buried over a long period of time.

Sedimentary: Due to deposition of material (flow

of fluid accumulates layers of different material)Exudates: Fluids originating from plants or

animals that accumulate in an area

Coal is classified with its TYPE and RANK.

Type: Plant sources from which it is derived

Rank: Measure of the age of coal(Degree of metamorphosis/growth)


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Energy in CoalFrom the viewpoint of energy, coal is classified in terms

of its gross calorific value (energy per unit mass).

The amount of heat produced by combusting a

certain quantity of fuel.

GCV can be estimated using the following in KJ/kg:

Where C, H, O, S are percentage compositions of Carbon,

Hydrogen, Oxygen and Sulphur obtained after fuel analysis.

Before calculating GCV of the given coal, its chemical

composition is determined.

SOHCQ 22)]8/([1427339


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Why is it calorific value when its expressed in Joules!

Calorie was an old unit, which has now been replaced by

Joules in ISU.

1 (small) calorie is approx. 4.2J

Calorie by definition is:The amount of energy that raises the temperature of

1gm of water by 1oC.

Replace 1gm with 1kg in the above definition and you

have 1 large calorie.


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Exercise:

Calculate the gross and net calorific value of coal which

has C 74%, H 6%, N 1% O 9% S 0.8% and moisture 2.2%.

SOHCQg 22)]8/([1427339

GCV can be estimated using the following in KJ/kg:

Using all values, Q=32060.2KJ/kg.

The net calorific value subtracts the heat of vaporization

of water vapour from the gross value.

NCV is given by:

Hence, NCV comes out to be: 30686.67KJ/kg.

)9(44.24 MHQQ gn

Courtesy: Prof. S. C. Koria, IIT Madras


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Coal Reserves & Environment

Coal is one of the most abundant fossil fuel contributingsignificantly to the world energy needs.

Exact amount cannot be determined because new coal

mines continue to be discovered, old ones get depleted.

Combustion of coal releases NO2 and Sulphur that may

cause acid rain.

Rain with a low pH value, harmful for plantation.

Biggest concern with coal fired stations is environment.

Can you think of another one?Coal reserves shall finish one day!

http://www.youtube.com/watch?v=TfIfxmni_Eg


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http://www.youtube.com/watch?v=TfIfxmni_Eghttp://www.youtube.com/watch?v=TfIfxmni_Eg


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Oil

Oil is a highly flammable, naturally occurring liquidthat is a mixture of various hydrocarbons.

It is formed when dead organisms (algae) bear intense

pressure and temperature beneath the Earths crust.

Oil is usually discovered buried under the sedimentary

rock reserves.

With advances in drilling technologies, oil is also beingextracted from the deep ocean sea bed.


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Ancient HistoryAristotle believed that oil and other

fossils are formed deep beneath the

Earths crust.

Two theories emerged in 1500s:

- Agricola (1546) agreed with Aristotle

and suggested that bitumen (oil)

comes from sulphur inside Earths

crust.

- Libavius (1599) suggested bitumen came from the

remains of dead trees.

http://www.sjvgeology.org/oil/oil.html


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http://www.sjvgeology.org/oil/oil.htmlhttp://www.sjvgeology.org/oil/oil.html


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Environmental Impact

Oil is taken out from deep sea bedsusing pipeline assembly.

If something wrong happens

to the pipe, the phenomenon

of oil spill takes place.

Oil spill introduces hydrocarbon into

the environment.

http://www.youtube.com/watch?v=XLiqvZOP8TY

A recent accident in the gulf of Mexico had tremendousaffects on the environment.


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http://www.youtube.com/watch?v=XLiqvZOP8TYhttp://www.youtube.com/watch?v=XLiqvZOP8TY


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Natural GasNG accounts for over 20% of world energy needs.

This kind of fuel is most environment friendly because

it releases fewer hydrocarbon.

Trade of Liquified Natural Gas (LNG) has seen massivegrowth over the past few years.

Super-cooled to -120 to -170oC

Energy density is comparable to oil!

Compressed Natural Gas (CNG) is compressed to a

pressure of 20-25MPa.

Lighter than air so leaks away and prevents fire.


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Chemical Formulae

Oil: It is a complex mixture of alkanes (CnH2n+2),cycloalkanes or napthenes (CnH2n) and benzene (CnHn)

Cycloalkanes have similar properties as alkenes but

have higher boiling points.

Composition of oil and its properties may also vary.

Natural Gas: Methane CH4

Coal: The chemical formula of coal has been estimated

as C135H96O9NS


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Fuel Consumption and ProductionFigures recorded for period 2000-2009:

Increase in

consumption by

Increase in

production by

Oil 10% 6.85%

Natural Gas 23.3% 24.14%

Coal 40.24% 51.71%

http://gtadailythoughts.wordpress.com/2011/01/12/energy-consumption-comparison-oil-gas-and-coal/

All these sources of energy are termed as Fossil fuels

because they are formed beneath the Earth surface by

dead plant and animal decomposition.


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http://gtadailythoughts.wordpress.com/2011/01/12/energy-consumption-comparison-oil-gas-and-coal/http://gtadailythoughts.wordpress.com/2011/01/12/energy-consumption-comparison-oil-gas-and-coal/http://gtadailythoughts.wordpress.com/2011/01/12/energy-consumption-comparison-oil-gas-and-coal/http://gtadailythoughts.wordpress.com/2011/01/12/energy-consumption-comparison-oil-gas-and-coal/http://gtadailythoughts.wordpress.com/2011/01/12/energy-consumption-comparison-oil-gas-and-coal/http://gtadailythoughts.wordpress.com/2011/01/12/energy-consumption-comparison-oil-gas-and-coal/http://gtadailythoughts.wordpress.com/2011/01/12/energy-consumption-comparison-oil-gas-and-coal/http://gtadailythoughts.wordpress.com/2011/01/12/energy-consumption-comparison-oil-gas-and-coal/http://gtadailythoughts.wordpress.com/2011/01/12/energy-consumption-comparison-oil-gas-and-coal/http://gtadailythoughts.wordpress.com/2011/01/12/energy-consumption-comparison-oil-gas-and-coal/http://gtadailythoughts.wordpress.com/2011/01/12/energy-consumption-comparison-oil-gas-and-coal/http://gtadailythoughts.wordpress.com/2011/01/12/energy-consumption-comparison-oil-gas-and-coal/http://gtadailythoughts.wordpress.com/2011/01/12/energy-consumption-comparison-oil-gas-and-coal/http://gtadailythoughts.wordpress.com/2011/01/12/energy-consumption-comparison-oil-gas-and-coal/


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Oil/Gas-fired Power plant

Turbines used in such plants can operate on both naturalgas and low-sulphur oil.

Two fuels increase reliability of power generation.

Courtesy: Tennessee Valley Authority


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i h


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Nuclear FuelUses Uranium and Thorium as source of fission energy.

Uranium is a natural nuclear fuel.

Thorium is converted into fissionable material.

Thorium reserves are 4 times as large as Uranium.

Fission process of Uranium atom releases 200 million

eV of energy.

Note that burning one carbon atom releases 4eV.

Nuclear energy, consumed at the current rate, can

provide world energy needs for the next 1000 years.


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C i h F H FHNG SKKU 2014


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Nuclear Fuel: UraniumIn 1789, Uranium was discovered as a new naturally

occurring element.

Named after the newly discovered planet Uranus.

Radioactive nature was discovered in 1896.

Composition of Natural Uranium:

99.2175% U238 (fissionable)

0.72% U235 (fissile)

A low energy neutron can start the chain reaction,if fissile material is used.

U238 half-life is about 4.5 billion years.


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C i ht F H FHNG SKKU 2014


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Nuclear Fuel Cycle

1000kg ore contains 1-2kg

of Uranium.

U3O8 (yellowcake) is found

naturally with 80% purity. It is

converted into UF6 by removing

20% impurities.

Reactors house 5000kg of

Uranium that supplies

160GWh of electricityIncreasing the percentageamount of U235 is called

enrichment. U235 is naturally

fissile (sustains chain reaction

for nuclear fission).


[email protected]: US Nuclear Regulatory Commission.

C i ht F H FHNG SKKU 2014


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Nuclear Hazards

Chernobyl Accident 1986(Worlds worst nuclear accident)http://www.youtube.com/watch?v=vnjzVNG18jo&feature=related

Fukushima Nuclear Disaster 2011(Second worst nuclear accident)http://www.youtube.com/watch?v=6Cy-PHxt2u8

Radiation leaks were discovered again at Fukushima facility.

- September 2013


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Cop right Fara Hasan FHNG SKKU 2014
http://www.youtube.com/watch?v=vnjzVNG18jo&feature=relatedhttp://www.youtube.com/watch?v=6Cy-PHxt2u8http://www.youtube.com/watch?v=6Cy-PHxt2u8http://www.youtube.com/watch?v=6Cy-PHxt2u8http://www.youtube.com/watch?v=6Cy-PHxt2u8http://www.youtube.com/watch?v=vnjzVNG18jo&feature=related


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Renewable Resources

Renewable resources do not burn any fuel. The energycomes directly from nature.

The biggest problem is that the supply of energy is

irregular or intermittent.

It has been recently pointed out that:With large-scale connectivity, averaging effects come into play

and uncorrelated regional intermittencies can partially cancel

each other out.

Work is in progress to develop an Asian grid comprising

of countries having considerable renewable potential.

Taggart, James, Dong, RussellThe Future of Renewables Linked by a Transnational Asian Grid,Proceedings of the IEEE, 2012.


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Copyright Faraz Hasan FHNG SKKU 2014


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DESERTEC Industrial InitiativeThe EU countries are also working on similar ideas.

The solar power plants in the Middle East and North

Africa (MENA) can satisfy 70% of MENAs electricity needs

and 17% of the EU electricity needs.

The solar energy may be transmitted via high-voltage

direct current (HVDC) lines across North Africa and

connected to Europe across the Mediterranean Sea.

North Sea wind and Icelandic geothermal energy feeding

into European grid via HVDC cables is being considered.


[email protected], James, Dong, RussellThe Future of Renewables Linked by a Transnational Asian Grid,Proceedings of the IEEE, 2012.



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Transnational Asian GridWhy Asia?

Most Asian countries are rich in

renewables.

China and Mongolia have wind,

Australia has solar energy.

Countries included in the grid:China, Japan, South Korea,

ten Association of Southeast AsianNation (ASEAN) states, and Australia


[email protected], James, Dong, RussellThe Future of Renewables Linked by a Transnational Asian Grid,Proceedings of the IEEE, 2012.



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Wind and Solar ResourcesWind power over a

period of 1-week in 2010.

The y-axis in both figures is

relative to the total installed

capacity of each region.

Solar power over a

period of 1-week in 2010.


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Generating electricity:Rotate a conductor within a

magnetic field to generate

electricity.

- Loose form of Faradays law

Courtesy: Tutor vista online

Conversion principle

Where to provide rotation?

Find an intelligent way to extract

rotational energy!

Using hydraulic turbines:http://www.youtube.com/watch?v=cEL7yc8R42k


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http://www.youtube.com/watch?v=cEL7yc8R42khttp://www.youtube.com/watch?v=cEL7yc8R42k


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Generator OutputA generator converts mechanical energy (using rotating

devices) into electrical energy.

Recall that we defined power as an ability to do work.

Hence generators are rated in terms of their output

power (not energy).

Power P is expressed as the product of voltage Vand

current I.

The total electric power produced by a generator can be

classified into two types.

Total power

Useless (Reactive) power

Useful (Active) power


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Reactive PowerReactive power is consumed in electric machines to

energize different components.

- It does not contribute to the main output.

- Also called wattless, useless or imaginary power.

When voltage is applied across an inductor, the currentdoes not build up straight away.

Some of the power only energizes the inductor.

Joe Duncanson, Electrical Basics Part 2 (available online)


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Reactive PowerAny machine using a magnet, consumes some portion of

input energy to align the domains of magnetic material.- Domain alignment theory

Courtesy: processmodeling.org.

The amount of power required to energize a device (align

its domains) is called reactive power.


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Active and Total PowerActive power is the component of total power that is

the useful output of a machine.

Also called wattful, useful or real power.

Total power (or complex/apparent power) S, is the

vector sum of active power P and reactive power Q.

Courtesy: PowerStar


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Types of Electric Power Units

Active power is expressed in WattsMathematically, it is VICos.

Reactive power is expressed in VAR (volt-amperes reactive)

Mathematically, it is VISin.

Total power is expressed in VA.

Mathematically, it is VI

Fundamental formula for power (voltagetimes current) that we study in junior

classes is actually for total power only.

Coke analogy

Courtesy: Minnesota Valley Electric Cooperation


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Power factorRatio of real power to the total power is power factor.

Power factor expresses the percentage usefulness of

the available power.

Power factor of 0.8 infers that 80% of the available

total power has been used in a useful manner.

The absolute value of the cosine of the angle between

voltage and current is called the power factor!


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Power factor Analogy

Courtesy: Alpha power solutions

The horse is moving on a road. The cart it is pushing is

moving on the track.

Active Power: Power applied by the horse in the

direction of the track is useful only.


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Problem:

A generator produces 100KVA, all of which is directly fed to a load

operating at power factor 0.8.(a) What is the amount of reactive power consumed by the load?

(b) By how much percent does the required reactive power

reduce, if power factor changes to 0.95?

py g , , ,

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Short video: http://www.youtube.com/watch?v=kjbsa1kHj2c&feature=related

Power factor compensationInstead of providing reactive component from the same

generator, use some other source, such as capacitors.

This way, the long transmission line from generator to

load shall not have to contain reactive power.

py g , , ,

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http://www.youtube.com/watch?v=kjbsa1kHj2c&feature=relatedhttp://www.youtube.com/watch?v=kjbsa1kHj2c&feature=related


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Transmission Lines & Reactive Power

The size of the transmission wire varies with the amount

of power it handles.

To support high power transmission, large sized wires

are required (cost increases!)

Power loss occurring in the wire is proportional to I2R.Higher the current through the transmission line, higher

the power loss.

If reactive power is supplied locally, transmission lines willnot have to carry too much power!

py g , , ,

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Seminar AnnouncementSeminars are scheduled in Week-7 and week-9.

- 3 to 4 students should form a group. Each group should select one

research paper and make a detailed presentation on it.

- Papers should be taken from IEEE-indexed conferences and should

not be older than 2012.

- Only 1 student from each group shall present but all group

members must participate in the Q/A session.

- Assessment criteria:

Clarity: 40% Depth of discussion: 30% Q/A: 30%

- Grading shall be on per-group basis (not on per-student basis)

You must email me about your group members and selected papers

by 30 March, Sunday.

py g

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Lecture 2 Resources Power