8/16/2019 Design and Economy of Renewable Energy Sources to Supply

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20

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International

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Prague 8 11 June

2009

Paper 0404

DESIGN AND ECONOMY OF RENEWABLE ENERGY SOURCES TO SUPPLY

ISOLATED LOADS AT RURAL AND REMOTE AREAS OF EGYPT

(2)

(3)

and the

AblaGADO

Rural Electrification Authority, Ministry of

Electricity

&

Energy, Shebin El-kom, Egypt

dr aagado@yahoo.com

ABSTRACT

Meteorological conditions in many sites of the world

countries as well as in Egypt are well adapted to install

more than one

of

renewable energy sources (RESs) to

supply electrical loads. Solar and wind energies are the

most convenient and economic types of RESs pertaining

the Meteorological conditions

of

Egypt. Also, the main

type

of

isolated loads at rural and remote areas

of

Egypt is

pumping loads for irrigation purposes. So, three

alternatives

of

solar photovoltaic and wind energy

systems can be used to supply these loads. In this work, a

proposed model has been introduced to evaluate the

design and economy

of

these alternatives to supply

isolated loads in a remote area. This model is used also

for optimizing these alternatives

of

RESs from

economical point

of

view. The proposed model depends

on the Meteorological data at the installation site, the

performance

of

solar photovoltaic and wind energy

systems used, the type and capacity of energy storage

facility employed, the economical parameters of these

resources and load.

The proposed model is applied numerically to design

three alternative sources

of

solar photovoltaic and wind

energy systems to supply an isolated load in a remote area

of

Egypt. The economy

of

these sources are determined

and compared to develop the most economical one of

these RESs.

Introduction

More than small villages in remote areas ofEgypt have no

reliable source and had no local transmission grid. These

areas extend from 22° N up to 31.5° N and enjoyed with

3000 to 4000 hours

of

sunrise per year [1]. Most of these

areas have yearly average wind speed of 10meters per

second [ 2]. So, the actual energy needed for these

villages

of

Egypt offer a rewarding opportunity for the

utilization solar and wind energy system can be used to

supply electrical loads in such areas. But, the

intermittency

of

solar radiation and wind speed is the

main problem

of

these sources . The solution of this

problem is in general employing energy storage facilities

or small diesel-generator to supply loads at the time of

unavailability output

of

these RESs. On the other hand,

diesel generator is unreliable and costly [3]. Also, the

storage battery is the major cost element of RESs, have a

limit life-time and require regular maintenance [4].

Therefore, the design and economy

of

solar photovoltaic

(PVS) and wind energy (WES) systems depends on many

variables, namely; the meteorological data at the

Atef EL-ZEFTAWY

Dept ofElec. Engineering, Faculty

of

Engineering,

Menoufiya University, Shebin El-kom, Egypt

AtetElzeftawy@yahoo.com

installation site, the performance

of

PVS and WES used,

the type and capacity of energy storage facility employed

, the economic parameters of these resources and load.

In previous publications [5], a proposed generation

model has been introduced to develop the availability of

PVS and WES to meet an isolated load. Also, a proposed

technique has been given to find correlation between the

outputs of wind energy system and load demand in order

to decrease the whole power cost [6]. In other references

[7,8] , load management techniques are suggested to

minimize the capacity

of

storage battery with power

suppliers in remote areas.

In this work, a proposed generation and cost model has

been introduced to develop the economical source of three

options of RES to supply an isolated load. These options

are solar photovoltaic or/ and wind energy systems

accompanied with energy storage facility.

2. PROPOSED APPROACH:

The model aims to develop the economical source of

three options

of

renewable energy sources to supply an

isolated load in remote areas. This load comprises several

individual loads such as residential and water pumping

loads. The study options ofRESs are shown in Fig

.l

and

the specification

of

these options are given below:

l-Solar photovoltaic power system accompanied with an

energy storage facility (ESF).

2-Wind energy system accompanied with ESF.

3- Solar photovoltaic and wind energy system

accompanied with ESF

The design and cost of each option are modeled here as

followings:

Option 0):

The generation system in this option is PVS and two of

energy storage facilities. These facilities are battery and

water storage (basin) for irrigation, Fig. l-a, The hourly

insolation and the average monthly temperature through

the year months at the installation site may be used for

designing PVS as follows:

a- The hourly generation

of

a standard PVS has a peak

power of IkW and number

of

modules m through the

year months (Pe(i

j»)

is given as follows [9]:

  PC i,})) = m * VC i.}) * f c i,})  l )

Where the hourly voltage (Ve(ij») and current

(le(ij»)

of one

PVS module through the i th hour

of

the month j of the

year are:

VC i,})

=

24 -2.1

*

1 0 3  TcO)

-

25)

f c i,})=

1.35

H i.}) +

O.5*1O 3 Tcor

25

Where and T

e

G

are solar insolation

CIRED2009

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Prague, 8 11 June

2009

Paper

0404

Fig-la- Option (1); solar photovoltaic system and ESF.

Option (2):

A wind energy system (WES) accompanied with

storage battery and water storage (basin) is used here to

supply the load demand as shown in Fig. l-b. The hourly

output of WES through the year months (Pw ij» is

deduced as a function

of

the installat ion site and WES

characteristics as in reference [5].

The annual energy output of this WES (Ec) is given as:

Irrigation

 

Plant

;,

Pump1

' Water

basin

Residential

:;

load  

~

- . : -    

....-=;...-

CI C Storage AC/DCcn erter

convert battery

Fig-lb- Option (2); wind energy system and ESF.

t; =LL PW i

,} )

 13

Consequently, the

number

ofwind-generator of rated

power, P

wg

required to meet the load demand is obtained

from equations 7 and 13.

The mass balance equation between the generation

and load in this option is given as:

P

) ~ P I

= P  W i,j) +PS i,j) + P sp i,j)

 14

Where;

P w i,j)

is the direct wind generation used.

Computer package in reference [10] is used to assess the

capacities of the storage battery and water basin required

for this option ofRESs.

The cost function

of

this option   f

02

) is given as:

£; 2

=

f

w

+ fs (15)

Where f

s

is given as in equation

11

and f

w

is cost function

of the WES and given by:

f

w

= N

w'

D

w'

cw'Pwg (16)

where N

w

D;

and

Cw

are the number of wind generator

(WG) used, the annual discount rate and the capital cost

per

1

kW

of

the WG have rated power

ofP

wG

•

WESn , -.... , - - - - . . / . { r igation

  7'; - r  , Water r an.t,

  pu p\

 

-' basin

P : i , ~ P S i,J +

P P

i,J (17)

Where; v  i.j)

+ w

i,}) - PL i ,}) (18)

Thus, the rated and peak power of WES and PVS, and

capacities

of

the storage battery and basin are determined

for this option. The cost function of this option of RESs

  o3) is given as:

1 3=Iv +Iw +Is  19

Where  v Iwand

Is

are determined from equations 10, 16

and 11 respectively.

WES: ·I..

- r - ,

PVS

 > : ··.• )

,.. -' ..

I

/ DClAC

/- '-,/ - / - / ' cd ivertt

, f . ,I . / .... ;...../

l -

  ' I Residential

 

:

,.

load

Fig-lc. Option (3) Solar photovoltaic & wind energy

system and ESF.

3. APPLICATION:

The proposed model in section 2 is applied to supply

an isolated load at EL-kharga oasis (25

0

27

N) in the

western desert

of

Egypt. Fig -2 gives the average daily

Option (3):

Solar photovoltaic and wind energy systems

accompanied with storage battery and water storage

(basin) are used here to feed the load demand, Fig .

l-c

.

The mass balance equation between the hourly

generation P1 ij) for this option

ofRES

s

is given by :

Irrigation

plant

.

Residential

---- +

  load

-----,..-.

Pump

Water

C;

  > basin

/ : ~ > :

:-

·1

;

'.'

.L

battery

temperature through i th hour of the month

j

respectively.

The annual DC energy, EJ:DC) and AC energy EJ:AC)

outputs

of

this PVS are given as:

Ev DC) =

L L ~ i  4

Ev AC)

= 1 J ~

>Ii

Ev DC)  5

Where

1]pc

is the efficiency

of

inverter.

b- The power and energy requirements for load comprises

residential and pumping loads can be stated as:

PI

i,})

= Pr

i,j)

+

P p i,})

 6

s,

=L L r.;

  7)

Where

P . i ~

Pr(J) and Pp(ij) are the total hourly, residential

and pumping loads through the j th month and E. is the

total annual load.

E q u ~ t i o n s 5 and 7 reveal the peak power of PVS, P

vp,

required for meeting the load demand,

c- The mass balance equation between PVS generation

and load is given by:

PV i

,} ) = = P : i ,} ) + +

P SP

,} )  8

Where; p  \{iJ), P

s(ij)

and Psp ij) are the direct and storage

powers for residential and pumping loads through the i th

hour of the j th month .

This model can be used with a published computer

package [10] to find correlation between PVS generation

and load, and estimate the capacities of storage battery,

CBs, and water basin, Qs

p

be used for supplying

residential and pumping loads at non- powering

ofPVS

.

The cost function ofthis option ofRESs is:

 o

= Iv

+

Is  9

Where f

v

and

fs

are the cost functions

of

PVS and storage

facilities used which are given as:

Iv =

o,

*c

v

* r; (10)

f s=D

sCB

s+

o,*c

p

*Ep+D

sp

*c

sp

*Qsp (11)

where D ; D; D

sp

and D

p

are the annual discount rate

of

PVS CBs: Qs

p

and the annual energy required for pumps,

E

p'

and given by

[11] :

D

=

r 1+rl / [ 1+rl-l]  12

Where, r,n are the interest rate and life time of the

considered system.

PVS

CIRED2009 Session 4

Paper No

0404

8/16/2019 Design and Economy of Renewable Energy Sources to Supply

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IRE

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20

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International Conference

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Electricity Distribution

Prague

,

8 11 June

2009

Paper

0404

load curve through a year. This figure illustrates the

categories

of

the load at the considered site [5].

Fig-2 average yearly daily load curve

at El-kharga oasis [5].

Solar radiation, temperature, wind speed and its

direction, humidity and air pressure have been measured

by the Meteorological Authority of Egypt at the

considered site [1,2]. These data are utilized with the

previous published models [9,12] to estimate the solar

radiation received on PVS array, and wind speeds

through the year seasons (months). Fig. 3 gives the daily

solar radiation received on unit area

of

the PVS array

through the year seasons. While, Fig. 4 depicts the hourly

wind speed at the study site. Results

of

these figures are

used with the proposed model in section 2 to determine

the design and economy

of

the suggested RES options to

supply the load demand in Fig. 2. This load curve can be

modified to generate water pumps through the hours of

high insolation [6].

carrying out this application:

l-Wind-generators

of200

kW rated power are used.

2- A storage source battery is used to supply residential

loads, while a basin is used for irrigation at non

powering ofRESs.

3- The charge source for the pumping storage is restricted

by the permitted loading in PVS and WES, while the

storage battery is charged from PVS in option 3.

4- Water- pumps are driven by a 5 HP, 220 v induction

motor.

5- When the feeder pump is operating it can delivers 40

% of the basin capacity in one hour . While, the

irrigation plant's operation requires 20

%

of the basin

capacity each hour.

6- The economical parameters of PVS, WES and storage

facilities are taken from references [11,13].

7- life- time of PVS and WES is taken as 20 and 30

years, while the life- time

of

the storage battery, water

pump-set , and water basin are 2.5 and 50 years

respectively.

The computer pakage in reference [10] is applied to

estimate the peak power ofPVS, the number

ofWES

, the

capacity

of

the two storage facilities used and the cost

function of the suggested three options to supply the

given load. The results

ofthis application are summarized

as follows:

Option 1 Option2 Option 3

Peak power ofPVS, kW 2664.5 21

Number ofwind-generator 2 1

Capacity

of

the storage 664 473 440

battery, Ah

Capacity

of

the reservoir, m'

2475 3150 400

Cost function,

1.

E.lyr

226465 206769 125401

The above summarized results concluded that opion (3)

has small capacity

of

storage battery and storage water

(basin) compared with other options. So, this option is the

economical source

of

RESs to supply the load demand at

the considered site

of

Egypt. Also, it should be declare

that the utilization

of

PVS with energy storage facilities,

option (1), is costly due to the high cost

of

PVS elements

and big capacity of the energy storage facilities require

for this source.

a) Spring season

Dayllours

-

_

March

_· · -April

-

Mo

,

0000

 00

i

c

600

500

400

.iii

300

S  00

'00

,

I-,

-,   ~   -,,-.

- ,,

->

, - ,- -,,

i

  2O: l-,_ _, - -, _,_

t:

_ ~ , , , _

 

- . .. .  Decerrtl&r

·· ·

.· ·

·January

- february

6 8 10 12 14 16 18 20

DrI, llours

a) Winterseason

90  

A.Jlping load

80

  .Residential load

70

60

.....

.

-

50

., j

40

30

20

10

0

0 2 4 6 8

1Bay

16 18 20 22 24

N •• _ _• Jul)t

8)() . - A..gust

eoo

..

.

.

i ..

D> '

o

800

600

•

'DO

e

200

0

  -

----.-----,.-----.-------.- .------.----.- -.-------.- .-----.-------,

o 2 4 6 8 10 12 14 16 18 20 22 24

Day h

our

s .

Fig. 4 the average hourly wind speed at the study site

through a day

of

different year seasons.

The following assumptions are considered through

a) Summer season a) Autumn season

Figure 3. The hourly solar radiation at

El-kharga

site

throygh a day

of

different year months.

4-CONCLUSION:

A proposed model is presented in this paper to design

three alternative sources

of

solar photovoltaic and wind

energy accompanied with energy storage facilities to

supply isolated loads. Also, an economical model for

optimizing these renewable energy source alternatives

has been introduced. The proposed model is applied

numerically to design the suggested RES alternatives in

order to supply an isolated load in a remote area of Egypt.

Moreover, the economies

of

these alternatives are

deduced. The remarkable results

of

this application may

summarize as given below:

1- Option (3), solar photovoltaic and wind energy

systems accompanied with energy storage facilities, is the

most economical source of the study RES alternatives

(125,401 L.E./yr). While, option (1), solar photovoltaic

 

Spring

  S

UrTTT

r

  Autunm

- - - - IMnter

10

1:

6

14 .......

 E

~ 2

CIRED2009

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AblaGado

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2009

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Atef El-zeftawy

power system accompanied with energy storage

facilities, is very high cost (226465 L.E./yr). The annual

cost of option (2) is 206769 L.E ( 1.0 = L-E 5.5).

2- Utilization of different type of RESs to supply

electrical loads in remote areas decrease the capacity of

energy storage facilities and the corresponding costs.

REFERENCES

[1] The European Commission and United Nation

Development Programming; Energy as a Tool for

Sustainable Development Programming; forAfrican,

Caribbean and Pacific Countries E and Coweb site,

www.Energy house.com, 1999.

[2] New and Renewable Energy Authority; Egyptian

Solar Radiation Atlas Cairo, Egypt, 1998.

[3] Photovoltaic(http://

en.wikipedia.org/w/index.php?title- photovoltaic&

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[4] AL-Ibrahim,

AM

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Mitchell,

lW

.; Design Proceedure for Selecting on

Optimum Photovoltaic Pumping System in a Solar

Domestic Hot Water System Solar Energy, Vol. 64,

Issues 4.6, December 1998, pp. 227-239.

[5] Ahmed, G.E.; Photovoltaic- Powered Rural Zone

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[6] Large-Scale, Cheap Solar Electricity

(http: //www

.technologyreview

.com/red-artide

aspex?id=17025&ch=biztech).

[7] Building integrated photovoltaic

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[8] Eraky, S.A.; Assessment of Operating Photovoltaic

Power System for Residential Loads Ph. D. Thesis,

Faculty of Engineering, Menoufiya University,

Egypt, 2000.

[9] Aly,G.e.M, El-zeftawy, A

A,

Eraky, S. A and

Abou-Elazm.A . M.; Modelling of Alternative PV

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Proceedings of 9 th International Middle East Power

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December 16-18

,2003,

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[10] Abou-Elazm, A.M., Aly, G. E. M., El-zeftawy, A

A , Eraky, S. A.; Optimizing of Alternative PV

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[11] Edin, R. ,Ponser, M., Bending, R., Couch, E. and

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[12] Salameh, Z.M.; Photovoltaic Module- Site

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[13] Alsema, E.A, Wild Scholten, M.J.de; Fthenkis,

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[14] Ministry of Electricity and Energy of Egypt,

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CIRED2009 Session 4

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