traditional energy systems

7/28/2019 Traditional energy systems

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Chapter - 2

1. Traditional energy systems (2 hours)a. Sourcesb. Applications

i. Transport bullock cart, horse carriage, camelsii. Agriculture ox plough, water lifting devices

iii.

Human power bicycle, cycle rickshaw etc.iv. House hold cooking (bio mass), lighting etc

Module Sub-Modules Hours

per topic

Total

Hours

2. Traditional

energy systems

a. Sourcesb. Applications 11 2


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Chapter Objective1. To understand the relevance of muscle power2. To enable students to contemplate system designs that includes muscle power as

one of the hybrid energy components.

Chapter MotivationApplications for pumping up water and mass transport.

Sample Questions1. What is muscle power?2. Describe the energy capital and its comparative values for muscle power based

system.

3. What is draught power?4.

What are the draught animals?5. Give a comparative table of the power delivering capability of the various draughtanimals.


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Indian Institute of Science CEDT

1.Traditional Energy Systems

Introduction

For any activity involving other than muscle power a base energy and capital energy are

required. This can be illustrated considering following two examples:

Consider a person walking between 2 points A B. the energy required will be

Fd(=m*a*d) joules.

Now if the person uses a car the total energy will be Etranslational+Ecapital

Where Ecapital is the energy invested in making car.

A d B

Considering the example of energy required for ploughing a field:

When a tractor is used there energy spent on Ecapital. The various relative values can be

tabulated as follows:

Eplough KWh Ecapital KWh Energy efficiency

Traditional farming 6000 60 90%

Modern farming 6000 60000 10%

From above it is clear that though the energy efficiency for traditional farming is high

the time required for modern farming is less.

Sources

The working speed for most draught animals is about 1 metre/second (3.6 km/h, 2 mph).

A bull consumes about 3.3 Joules for each Joule of work. There are limitations on the


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Horse

4.0

(400) 0.13

500

(50) 1.0 500 10 18

Donkey1.5

(150)0.13

200(20)

1.0 200 4 3

Mule3.0

(300)0.13

400(40)

1.0 400 6 8.5

Camel5.0

(500)0.13

650(65)

1.0 650 6 14

Note: For animals of different weight the power output and energyoutput per day may be adjusted proportionatelySource: Tools for Agriculture, 1992http://www.fao.org/sd/EGdirect/EGan0006.htm

AnimalForceExerted(lbs.)

Velocity(ft/sec)

Power(ft-lbs/sec)

StandardHorsepower

ForceExerted(N.)

Velocity(m/s)

Power(W)

draft horse 120 3.6 432 0.864 535 1.1 587

ox 120 2.4 288 0.576 535 0.7 391

mule 60 3.6 216 0.432 267 1.1 293

donkey 30 3.6 108 0.216 134 1.1 147

man 18 2.5 45 0.090 80 0.8 61

http://www2.sjsu.edu/faculty/watkins/animalpower.htmMetric conversion by Tim Lovett

For a hard day's work the horse reigns supreme, delivering 500W for 10 hours. The ox is knownfor its compliance and is less fussy about food - a good choice for the less demandingapplications. The camel has the highest power output. Forget the donkey.http://geoimages.berkeley.edu/GeoImages/Powell/Afghan/100.htmlCamel powered pump in Afghanistan: For millenia waterwheels have been used to lift water forirrigation and domestic use.

This camel keeps walking in a tight circle to turn an axle which powers the waterwheel.

http://private.addcom.de/asiaphoto/burma/bdia085.htmAn ox crushes peanuts on a tiny mill in Thailand. Note the two arms - one steering the animal atthe neck, while the other takes the power from behind the animal.

Power for common activities


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plane with coefficient of friction =0.2 Whr/kg/m

Lifting a body of unit mass by unit height 2722x10-6

Whr/kg/m

Energy required for rotating a disc of J=2kg-m2 with an angular

acceleration =2 rad/sec2 per unit radian

1111x10-6 Whr

Energy required to raise the temperature of unit mass of water from

250 to 75058.05 Whr/kg

Energy required to deliver water from a horizontal pipe with a

delivery rate of 0.1lt/sec at a pressure of 20N/m2555.56x 10-6

Whr/kg/m

Energy required to move a body up an inclined plane inclined at an

angle 45

o

with an acceleration of 2m/s

2

with a frictional coefficient of=0.2

2863x10-6

Whr/kg/m

Energy required for physical activities of human being (M=68kg)

Walking at a speed of 7 km/hr for a time of 1hr 464x10-3 Whr

Running at a speed of 10 km/hr for a time of 1hr 812.7x10-3 Whr

Cycling at a speed of 16 km/hr for a time of 1hr 510.8x10-3 Whr

Swimming at a speed of 2.4 km/hr for a time of 1hr 557.33x10-3 Whr

Energy Storage

Typical rechargeable batteries 40-100 Wh/kg

Electrochemical capacitor 5-15 Whr/kg

Spring 0.1-0.3 Whr/kg


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Applications ofApplications oftraditional powertraditional power

NPTELNPTEL


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TransportationTransportation -- walkingwalking

Women carrying water by walkWomen carrying water by walk


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TransportationTransportation ox powerox power

Bull cart to transport people from oneBull cart to transport people from one

village to anothervillage to another


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TransportationTransportation human powerhuman power

Rickshaw to transport peopleRickshaw to transport people


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TransportationTransportation animal poweranimal power

Camel cart and elephant as a means ofCamel cart and elephant as a means of

transporttransport


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Some more examples of muscle powerSome more examples of muscle power


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Some more examples of muscle powerSome more examples of muscle power


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TransportationTransportation bicyclebicycle

Human power along with wheelsHuman power along with wheels


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TransportationTransportation bullock cartbullock cart


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OX powerOX power


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OX powerOX power

Lifting water for irrigation

ploughing

Flour mill


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Muscle power to lift waterMuscle power to lift water


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Muscle power to lift waterMuscle power to lift water

Traditional well with pulley


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Bicycle powerBicycle power

Bicycle for loads otherthan for human transportation


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Candle power for lightingCandle power for lighting


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Firewood powerFirewood power

Heating/ cooking Heating/ lighting


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Traditional Energy Systems

Introduction

For any activity involving other than muscle power a base

energy and capital energy are required.

This can be illustrated considering following two examples:Consider a person walking between 2 points A B. the energy

required will be Fd(=m*a*d) joules.

Now if the person uses a car the total energy will be

Etranslational+Ecapital

Where Ecapital is the energy invested in making car.


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Traditional Energy Systems-1

A d B

Considering the example of energy required for ploughing a field:

When a tractor is used there energy spent on Ecapital. The

various relative values can be tabulated as follows:

Eplough

KWh

Ecapital

KWh

Energy

efficiency

Traditional

farming

6000 60 90%

Modernfarming 6000 60000 10%


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Traditional Energy Systems-2

From above it is clear that though the energy efficiency for

traditional farming is high the time required for modern farmingis less.

Sources:

The working speed for most draught animals is about 1

metre/second (3.6 km/h, 2 mph).

A bull consumes about 3.3 Joules for each Joule of work.

There are limitations on the performance of animals, such as

sensitivity to food supply, getting sick etc.

S t i bl f i di id l i l i


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Sustainable power of individual animals in

good condition

Animal Typical

weight

kN

(kgf)

Pull-

weight

ratio

Typical

pull N

(kgf)

Typical

working

speed

m/s

Power

output

W

Work

ing

hours

per

day

Energy

output

per day

MJ

Ox 4.5(450) 0.11 500(50) 0.9 450 6 10

Buffalo 5.5 (50) 0.12 650 (65) 0.8 520 5 9.5

Horse 4.0(400)

0.13 500 (50) 1.0 500 10 18

Donkey 1.5(150)

0.13 200 (20) 1.0 200 4 3

Mule 3.0(300)

0.13 400 (40) 1.0 400 6 8.5

Camel 5.0(500)

0.13 650 (65) 1.0 650 6 14



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good condition-2

Animal Force

Exert

ed

(lbs.)

Velocit

y

(ft/sec)

Power

(ft-

lbs/sec)

Standa

rd

Horsep

ower

Force

Exerted

(N.)

Velocit

y

(m/s)

Power

(W)

draft

horse

120 3.6 432 0.864 535 1.1 587

ox 120 2.4 288 0.576 535 0.7 391

mule 60 3.6 216 0.432 267 1.1 293

donkey 30 3.6 108 0.216 134 1.1 147

man 18 2.5 45 0.090 80 0.8 61



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good condition-3

For a hard day's work the horse reigns supreme, delivering

500W for 10 hours. The ox is known for its compliance and is

less fussy about food - a good choice for the less demandingapplications. The camel has the highest power output. Forget

the donkey.

http://geoimages.berkeley.edu/GeoImages/Powell/Afghan/100.html

Camel powered pump in Afghanistan: For millenia

waterwheels have been used to lift water for irrigation anddomestic use.

This camel keeps walking in a tight circle to turn an axle which

powers the waterwheel. http://private.addcom.de/asiaphoto/burma/bdia085.htm

P f ti iti


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Power for common activities

Activities Energy

Consumed

Moving a body of unit mass with anacceleration 2m/s2 on a smooth

horizontal plane

555.56x 10-6

Whr/kg/m

Moving a body of unit mass with anacceleration 2m/s2 on a horizontal plane

with coefficient of friction =0.2

1100x10-6

Whr/kg/m

Moving a body of unit mass withuniform velocity on a horizontal plane

with coefficient of friction =0.2

544x10-6

Whr/kg/m

Lifting a body of unit mass by unitheight

2722x10-6

Whr/kg/m

P f ti iti 1


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Power for common activities-1

Energy required for rotating a disc of J=2kg-

m2 with an angular acceleration =2 rad/sec2

per unit radian

1111x10-6 Whr

Energy required to raise the temperature of

unit mass of water from 250 to 75058.05 Whr/kg

Energy required to deliver water from a

horizontal pipe with a delivery rate of

0.1lt/sec at a pressure of 20N/m2

555.56x 10-6

Whr/kg/m

Energy required to move a body up an

inclined plane inclined at an angle 45o with

an acceleration of 2m/s2 with a frictional

coefficient of=0.2

2863x10-6

Whr/kg/m


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Energy required for physical activities of human being (M=68kg)

Walking at a speed of 7 km/hr for a

time of 1hr

464x10-3 Whr

Running at a speed of 10 km/hr for a

time of 1hr

812.7x10-3

Whr

Cycling at a speed of 16 km/hr for atime of 1hr 510.8x10

-3

Whr

Swimming at a speed of 2.4 km/hr

for a time of 1hr

557.33x10-3

Whr


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Energy Storage

Typical rechargeable batteries 40-100 Wh/kg

Electrochemical capacitor 5-15 Whr/kg

Spring 0.1-0.3 Whr/kg

traditional energy systems

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