effects of climate characteristics on wind power potential ... · eight-year meteorological data...

22
International Journal of Applied Environmental Sciences ISSN 0973-6077 Volume 13, Number 3 (2018), pp. 287-307 © Research India Publications http://www.ripublication.com Effects of Climate Characteristics on Wind Power Potential and Economic Evaluation in Salamis Region, Northern Cyprus Youssef Kassem 1,2 , Hüseyin Gökçekuş 1 , Hüseyin Çamur 2 1 , 2 Department of Civil Engineering, Civil and Environmental Engineering Faculty, Near East University, Nicosia, via Mersin 10, Turkey. 2 Department of Mechanical Engineering, Engineering Faculty, Near East University, Nicosia, via Mersin 10, Turkey. Abstract Eight-year meteorological data observed at Salamis region, Northern Cyprus, from 2009 to 2016 at 10m height, are studied to analyze the wind characteristics and wind energy potential by the assistance of Weibull distribution model. Therefore, the annual values of the Weibull parameters k and c are 9.008 and 3.127m/s, respectively, and the power density is16.724W/m2. Power law model is used to calculate the yearly and monthly mean wind speed at various heights. Based on the result, it can be concluded that the wind power density value in the region is considerable and can be exploited using small-scale wind turbines. Additionally, the economic analysis of 10 wind turbines model was estimated using present value cost method (PVC). Based on the results, the highest annual capacity factor was 51.1% using Finn Wind Tuule C 200 wind turbine, whereas, the minimum was found as 11.7% using the Enercon E53 wind turbine. Moreover, the lowest and highest values of annual electricity cost are obtained in the region as 0.00011$/kWh and 0.082 $/kWh using Enercon E82 and EolSenegal 500, respectively. Furthermore, wavelet transform of the time series is applied to study the relationship between wind speed, air temperature, and humidity. Keyword: Cross wavelet transform; economic evaluation; Salamis; Weibull distribution model; wind potential; wavelet transform; wavelet coherence

Upload: others

Post on 11-Jul-2020

3 views

Category:

Documents


0 download

TRANSCRIPT

Page 1: Effects of Climate Characteristics on Wind Power Potential ... · Eight-year meteorological data observed at Salamis region, Northern Cyprus, from 2009 to 2016 at 10m height, are

International Journal of Applied Environmental Sciences

ISSN 0973-6077 Volume 13, Number 3 (2018), pp. 287-307

© Research India Publications

http://www.ripublication.com

Effects of Climate Characteristics on Wind Power

Potential and Economic Evaluation in Salamis

Region, Northern Cyprus

Youssef Kassem1,2, Hüseyin Gökçekuş1, Hüseyin Çamur2

1,2 Department of Civil Engineering, Civil and Environmental Engineering Faculty, Near East University, Nicosia, via Mersin 10, Turkey.

2 Department of Mechanical Engineering, Engineering Faculty, Near East University, Nicosia, via Mersin 10, Turkey.

Abstract

Eight-year meteorological data observed at Salamis region, Northern Cyprus,

from 2009 to 2016 at 10m height, are studied to analyze the wind

characteristics and wind energy potential by the assistance of Weibull

distribution model. Therefore, the annual values of the Weibull parameters k

and c are 9.008 and 3.127m/s, respectively, and the power density

is16.724W/m2. Power law model is used to calculate the yearly and monthly

mean wind speed at various heights. Based on the result, it can be concluded

that the wind power density value in the region is considerable and can be

exploited using small-scale wind turbines. Additionally, the economic analysis

of 10 wind turbines model was estimated using present value cost method

(PVC). Based on the results, the highest annual capacity factor was 51.1%

using Finn Wind Tuule C 200 wind turbine, whereas, the minimum was found

as 11.7% using the Enercon E53 wind turbine. Moreover, the lowest and

highest values of annual electricity cost are obtained in the region as

0.00011$/kWh and 0.082 $/kWh using Enercon E82 and EolSenegal 500,

respectively. Furthermore, wavelet transform of the time series is applied to

study the relationship between wind speed, air temperature, and humidity.

Keyword: Cross wavelet transform; economic evaluation; Salamis; Weibull

distribution model; wind potential; wavelet transform; wavelet coherence

Page 2: Effects of Climate Characteristics on Wind Power Potential ... · Eight-year meteorological data observed at Salamis region, Northern Cyprus, from 2009 to 2016 at 10m height, are

288 Youssef Kassem, Hüseyin Gökçekuş, Hüseyin Çamur

INTRODUCTION

Climate variability and wind speed are completely interconnected. Although much

attention is given to the potential effects of climate change on surface temperatures,

humidity, and precipitation, there has been a comparatively minor discussion or

analysis of changes in wind speeds.

Wind energy is one of the most efficient renewable energy sources available but it

also requires a very detailed analysis of the wind characteristics of the selected region

[1]. Global wind speed is used to evaluate power generation of wind power plant over

a lifetime of the project [2]. Wind potential is a critical factor for the viability of wind

power generation, which is mainly affected by the cost of wind power generation in a

particular location. Many studies on wind characteristics and wind power potentials

over an extended period of time have been conducted worldwide recently [3–7].

Weibull statistical distribution is a common method for analyzing wind speed

measurements and determining wind energy potential [6, 8, 9]. Weibull probability

density function can be used to forecast wind speed, wind density and wind energy

potential [6].

In recent years, the growth of population and other factors in Northern Cyprus have

led to an increase in energy source demand such as fossil fuels. The environmental

problems associated with the use of fossil fuels have necessitated the development of

alternative energy sources such as wind energy for electricity generation. Therefore,

the need for a new clean source of energy that increases electricity production from a

renewable source is crucial.

The objectives of the study are: (1) to investigate the wind characteristics in Salamis

region, Northern Cyprus using Weibull function, (2) study the economic evaluation of

selected site using the method of present value of costs (PVC) and (3) examine the

climate characteristics (humidity, temperature and wind speed) of the region using

wavelet transform analysis to show the relationship between power density, economic

evolution and climate characteristics. The data used are collected from Meteorological

Department for eight-year period between January 2009 and December 2016.

Furthermore, power law model is used to calculate the yearly and monthly mean wind

speed at various heights.

METHODOLOGY

Weibull distribution function

In order to characterize the wind speed of any region, the model distribution function

is required. The two-parameter Weibull distribution function is widely used to

characterize the wind speed and to estimate wind energy potential in a region.

Weibull distribution of wind speed is represented as a probability distribution function

(PDF) and cumulative distribution function (CDF). Table 1 presents the probability

density function (PDF) and cumulative distribution function (CDF) of two parameters

Weibull distribution function. The method used for probability density function and

cumulative distribution function is the maximum likelihood method (MLM) was used.

Page 3: Effects of Climate Characteristics on Wind Power Potential ... · Eight-year meteorological data observed at Salamis region, Northern Cyprus, from 2009 to 2016 at 10m height, are

Effects of Climate Characteristics on Wind Power Potential and Economic Evaluation… 289

Table 1. Weibull distribution function for wind characteristic

Distribution function Equation References

PDF 𝑃𝐷𝐹 = (

𝑘

𝑐) (𝑣

𝑐)𝑘−1

𝑒−(𝑣𝑐)𝑘

[10-14]

CPF 𝐶𝑃𝐹 = 1 − 𝑒𝑥𝑝 [−(

𝑣

𝑐)𝑘

]

Parameters

Weibull shape parameter (k) 𝑘 = (

∑ 𝑣𝑖𝑘𝑙𝑛(𝑣𝑖)

𝑛𝑖=1

∑ 𝑣𝑖𝑘𝑛

𝑖=1

−∑ 𝑙𝑛(𝑣𝑖)𝑛𝑖=1

𝑛)

[10-14]

Weibull scale (c) [m/s]

𝑐 = (1

𝑛∑𝑣𝑖

𝑘

𝑛

𝑖=1

)

1𝑘

𝒗 wind speed value

The power of the wind (𝑃𝑣) that flows at speed v through a blade sweep area A

increases with the cube of its velocity and is given by [15]

𝑃𝑣 =1

2𝜌𝐴�̅�3 (1)

where �̅� is velocity in m/s, A is swept area in m2 and ρ is the density of air.

Monthly or annual wind power density (𝑃𝑤) per unit area of a site based on a Weibull

probability density function can be expressed as follows [15]:

𝑃𝑤 =1

2𝜌𝑐3Γ (1 +

3

𝑘) (2)

Where ρ = air density at the site. The air density is calculated using the following

expression [16]

𝜌 =353.049

𝑇𝑒(−0.034

𝑧𝑇) (3)

Where z is the elevation and T is the temperature at a considered site in [K].

Wind speed data extrapolation

For any wind project, it is very important to estimate the wind speed at the wind

turbine hub height. Therefore, The power law method is most commonly used to

estimate the wind speeds at various heights [17, 18]. It is expressed as:

𝑣

𝑣10= (

𝑧

𝑧10)𝛼

(4)

Page 4: Effects of Climate Characteristics on Wind Power Potential ... · Eight-year meteorological data observed at Salamis region, Northern Cyprus, from 2009 to 2016 at 10m height, are

290 Youssef Kassem, Hüseyin Gökçekuş, Hüseyin Çamur

where v is the wind speed at the wind turbine hub height z, 𝑣10 is the wind speed at

original height 𝑧10, and α is the surface roughness coefficient, which is depends on the

characteristics of the region [6]. The value of α can be obtained from the following

expressions [19, 20]

𝛼 =0.37 − 0.088𝑙𝑛(𝑣10)

1 − 0.088𝑙𝑛(𝑧10 10⁄ ) (5)

In most cases, the accurate value of the surface roughness coefficient is not readily

available or ascertained. Therefore, the Weibull parameters with height can be

estimated using Eqs. (6) and (7) according to Belabes et al. [4].

𝑐(𝑧) = c0 (𝑧

𝑧10)𝑛

(6)

𝑘(𝑧) =k0 [1 − 0.088ln (

𝑧1010)]

[1 − 0.088ln (𝑧1010)]

(7)

where c0 and k0 are the scale and shape factors, respectively, at the measurement

height 𝑧10, while z is the hub height. The exponent n is defined as [4]:

𝑛 =[0.37 − 0.088𝑙𝑛(c0)]

1 − 0.088ln (𝑧10)

(8)

Energy output of wind turbines

Power curve of the wind turbines and wind speed characteristics are the mean

parameters to estimate the wind energy of the turbine, Ewt, [21]. The total power

output of the wind turbine can be expressed by Eq. (9)

𝐸𝑤𝑡 =∑𝑃𝑤𝑡(𝑖)

𝑛

𝑖=1

𝑡 (9)

where t is the number of hours in the period under consideration.

The power curve of wind turbines can be approximated with a parabolic law as given

by [22]

𝑃𝑤𝑡(𝑖) =

{

𝑃𝑟

𝑣𝑖2 − 𝑣𝑐𝑖

2

𝑣𝑟2 − 𝑣𝑐𝑖2 (𝑣𝑐𝑖 ≤ 𝑣𝑖 ≤ 𝑣𝑟)

1

2𝜌𝐴𝐶𝑝𝑣𝑟

2 (𝑣𝑟 ≤ 𝑣𝑖 ≤ 𝑣𝑐𝑜)

0 (𝑣𝑖 ≤ 𝑣𝑐𝑖 𝑎𝑛𝑑 𝑣𝑖 ≥ 𝑣𝑐𝑜)

(10)

where 𝑣𝑖 is the vector of possible wind speed at a given site, 𝑃𝑤𝑡(𝑖) is the vector of

corresponding wind turbine output power (W), 𝑃𝑟 is the rated power of the turbine

(W), 𝑣𝑐𝑖 is the cut-in wind speed (m/s), 𝑣𝑟 is the rated wind speed (m/s) and 𝑣𝑐𝑜 is the

Page 5: Effects of Climate Characteristics on Wind Power Potential ... · Eight-year meteorological data observed at Salamis region, Northern Cyprus, from 2009 to 2016 at 10m height, are

Effects of Climate Characteristics on Wind Power Potential and Economic Evaluation… 291

cut-out wind speed (m/s) of the wind turbine. 𝐶𝑝 is the coefficient of performance of

the turbine, it is a function of the tip speed ratio and the pitch angle. The coefficient of

performance is considered to be constant for the entire range of wind speed [23] and

can be calculated as

𝐶𝑝 = 2𝑃𝑟

𝜌𝐴𝑣𝑟3 (11)

The capacity factor (CF) of a wind turbine is the fraction of the total energy generated

by the wind turbine over a period of time to its potential output if it had operated at a

rated capacity during entire time. The capacity factor of a wind turbine based on the

local wind regime of a given site can be estimated as

𝐶𝐹 =𝐸𝑤𝑡𝑃𝑟 . 𝑡

(12)

Economic analysis of wind turbines

The main parameters that govern wind power costs [24, 25] are

1. Capital costs, including wind turbines, foundations, road construction and grid

connection

2. Operation and maintenance costs.

3. Electricity produced, which depends on region and wind turbine

characteristics.

4. Discount rate and economic lifetime of the investment.

These factors may vary from country to country and region to region [25]. Table 2

tabulates the cost of wind turbine based on the rated power of the turbine [24, 25].

Table 2. Cost of wind turbines based on the rated power [25]

Wind turbine size [kW] Specific cost [US$/kW] Average specific cost

[US$/kW]

10 to 20 2200 to 2900 2550

20 to 200 1500 to 2300 1900

200 > 1000 to 1600 1300

Several methods have been used to estimate the wind energy cost such as PVC

methods [26]. The present value of costs (PVC) is given in [26] as the following

equation:

𝑃𝑉𝐶 = [𝐼 + 𝐶𝑜𝑚𝑟 (1 + 𝑖

𝑟 − 𝑖) × [1 − (

1 + 𝑖

1 + 𝑟)𝑛

] − 𝑆 (1 + 𝑖

1 + 𝑟)𝑛

] (13)

Page 6: Effects of Climate Characteristics on Wind Power Potential ... · Eight-year meteorological data observed at Salamis region, Northern Cyprus, from 2009 to 2016 at 10m height, are

292 Youssef Kassem, Hüseyin Gökçekuş, Hüseyin Çamur

where, r is the discount rate, i is the inflation rate, n is the machine life as designed by

the manufacturer, the 𝐶𝑜𝑚𝑟 is the cost of operation and maintenance, I is the

investment summation of turbine price and other initial costs, including provisions for

civil work, land, infra-structure, installation and grid integration and S is the scrap

value of the turbine price and civil work (see Table 3).

Table 3. Parameters of PVC

Parameter Value Parameter Value

r [%] 8 I [%] 68

i [%] 6 S [%] 10

n [year] 20 𝑪𝒐𝒎𝒓 [%] 7

The cost per kW h of electricity generated (UCE) can be determined by the following

expression [26]:

𝑈𝐶𝐸 =𝑃𝑉𝐶

𝑡 × 𝑃𝑟 × 𝐶𝑓 (14)

Measurement data

Cyprus is situated at latitude 35° North and longitude 33° East, surrounded by the

Eastern Mediterranean Sea. The surface winds over Cyprus are controlled by local

surface effects, such as the temperature contrast between land and open sea (land and

sea breezes), the differential heating of land (anabatic and catabatic winds) and the

constraints imposed by topography.

Air temperature, humidity and wind speed values at 10 m heights were measured

using thermometers, hygrometers and anemometers, respectively. Data were

measured continuously during the period from 2009 to 2016. The detailed geographic

information of the selected site is illustrated in Figure 1 and Table 4.

Table 4. Details of each station used in the analysis

Site Coordinates Height

[m]

Period Characteristics

of the site Latitude

[°N]

Longitude

[°E]

Salamis 35º07'52.2" 33º55'33.42" 10 2009-2016 coastal

Page 7: Effects of Climate Characteristics on Wind Power Potential ... · Eight-year meteorological data observed at Salamis region, Northern Cyprus, from 2009 to 2016 at 10m height, are

Effects of Climate Characteristics on Wind Power Potential and Economic Evaluation… 293

Figure 1. Location of the site used in this study

RESULTS AND DISCUSSIONS

Wind speed variation at 10 m height

Mean Hourly wind speed

The mean hourly wind speeds at different seasons: winter (December, January and

February), spring (March, April and May), summer (June, July and August) and

autumn (September, October and November) are presented in Figure 2. In winter, a

great deviation can be identified between the morning and the afternoon periods. A

steady wind speed is observed before 8am and increases sharply to reach the

maximum speed at 2pm. Also, the wind speed varies between 2 and 6 m/s. During the

spring, the daily variation in Salamis has a maximum which occurs at noon time (12

pm) and a minimum which occurs between 4 and 5 am. In summer, the maximum

mean daily variation speed values are recorded between 10 and 11am. In addition, the

mean wind speeds range between 0.5 and 7 m/s during spring and summer seasons.

Moreover, it is noticed that during autumn, the minimum and maximum wind speed

are obtained at morning time which occurs at 8 and 12am, respectively. In general,

the mean wind speed increases sharply after 6 am and reaches the peak-point around

12pm.

Page 8: Effects of Climate Characteristics on Wind Power Potential ... · Eight-year meteorological data observed at Salamis region, Northern Cyprus, from 2009 to 2016 at 10m height, are

294 Youssef Kassem, Hüseyin Gökçekuş, Hüseyin Çamur

Figure 2. Mean hourly wind speed (2009-2016)

Mean monthly wind speed

Mean monthly wind speed during the studied period from 2009 to 2016 is shown in

Figure 3. The highest monthly mean wind speed of 5.5 m/s occurred in February

2010, while the lowest mean wind speed of 2.1 m/s occurred in September 2015.

Generally, it is found that the mean monthly wind speed in the period from 2009 to

2016 was in the range of 2.1 to 5.5 m/s.

Page 9: Effects of Climate Characteristics on Wind Power Potential ... · Eight-year meteorological data observed at Salamis region, Northern Cyprus, from 2009 to 2016 at 10m height, are

Effects of Climate Characteristics on Wind Power Potential and Economic Evaluation… 295

Figure 3. Monthly mean wind speeds (2009-2016)

Mean yearly wind speeds

Mean yearly wind speeds for different seasons of the year 2009-2016 are plotted in

Figure 4. It is observed that the highest values of mean seasonal wind speed of the

area occurred during winter and autumn seasons. During these seasons, the wind

speed values are ranged between 2.24 and 3.74 m/s. Furthermore, it is noticed that the

minimum value of wind speeds occurred during summer.

Figure 4. Seasonal and annual wind speeds (2009-2016)

Average air density of the site

The air temperature values were collected during the investigated period (Figure 5).

Assuming that air is an ideal gas, average yearly air density values were calculated

using Eq. (7). The mean monthly air density values are shown in Figure 6. Also, mean

0.0

1.0

2.0

3.0

4.0

5.0

6.0M

ean

mo

nth

ly w

ind

sp

ee

d [

m/s

]

2009

2010

2011

2012

2013

2014

2015

2016

Average

2.0

2.5

3.0

3.5

4.0

2009 2010 2011 2012 2013 2014 2015 2016

Me

an m

on

thly

win

d s

pe

ed

[m

/s]

Winter

Spring

Summer

Autumn

Annual

Page 10: Effects of Climate Characteristics on Wind Power Potential ... · Eight-year meteorological data observed at Salamis region, Northern Cyprus, from 2009 to 2016 at 10m height, are

296 Youssef Kassem, Hüseyin Gökçekuş, Hüseyin Çamur

yearly air density values for the years 2009-2016 are tabulated in Table 5. The

average density values for 10 m were assumed to be constant for the other heights as

there will be no significant difference.

Figure 5. Average monthly air temperature in Salamis (2009–2016)

Figure 6. Monthly variation in air density (2009–2016)

0

5

10

15

20

25

30

35

Air

te

mp

era

ture

[℃] 2009

2010

2011

2012

2013

2014

2015

2016

1.14

1.15

1.16

1.17

1.18

1.19

1.20

1.21

1.22

1.23

1.24

De

nsi

ty [

kg/m

^3]

2009

2010

2011

2012

2013

2014

2015

2016

Page 11: Effects of Climate Characteristics on Wind Power Potential ... · Eight-year meteorological data observed at Salamis region, Northern Cyprus, from 2009 to 2016 at 10m height, are

Effects of Climate Characteristics on Wind Power Potential and Economic Evaluation… 297

Table 5. Mean yearly air density values (2009-2016) for Salamis

Year Average

Temperature [K]

Humidity

[%]

Average density

[kg/m3]

2009 295.81 68.2 1.192

2010 296.38 69.2 1.190

2011 295.52 68.0 1.193

2012 295.69 68.4 1.193

2013 295.78 66.2 1.192

2014 296.03 68.8 1.191

2015 295.67 67.9 1.193

2016 296.08 65.6 1.191

Frequency distribution of wind speeds at 10m height

The most important part of the measured wind speed data is its characteristics. An

evaluation of the data is needed to understand its characteristics. The characteristics

can be evaluated from the hourly wind speed, the daily wind speed, the monthly wind

speed, the annual wind speed, the wind speed distribution function, the mean wind

power and the energy density. The parameter estimates, shape (k) and scale (c), for

Weibull function have been performed using the maximum likelihood method are

tabulated in Table 6. Moreover, Figure 7 shows the Weibull distribution function,

described by its PDF and CPF, versus the mean wind speed, for data collected on an

annual basis from 2009 to 2016, based on parameters calculated using the maximum

likelihood method.

Table 6. Weibull parameters at height 10m

Parameters 2009 2010 2011 2012 2013 R2

k 12.50 8.03 5.82 4.63 3.75

0.987

c [m/s] 2.83 2.84 2.85 3.13 3.26

Mean [m/s] 2.77 2.62 2.62 2.80 2.92

WPD [W/m2] 12.59 12.49 12.52 16.95 19.73

Actual mean [m/s] 2.72 2.69 2.65 2.87 2.96

Observed WPD

[W/m2] 12.36 11.88 11.41 14.45 15.92

Page 12: Effects of Climate Characteristics on Wind Power Potential ... · Eight-year meteorological data observed at Salamis region, Northern Cyprus, from 2009 to 2016 at 10m height, are

298 Youssef Kassem, Hüseyin Gökçekuş, Hüseyin Çamur

Parameters 2014 2015 2016 Whole R2

k 7.692 5.316 4.555 9.008

0.987

c [m/s] 2.874 2.978 2.872 3.127

Mean [m/s] 2.701 2.734 2.560 3.079

WPD [W/m2] 12.909 14.397 13.078 16.724

Actual mean [m/s] 2.700 2.741 2.644 2.965

Observed WPD

[W/m2] 12.056 12.612 11.320 15.962

Figure 7. Wind speed probability frequency at height 10m

Shear profile and surface roughness of Salamis

The best wind speed for installing the wind turbine is 6.7 m/s and more, but it should

be mentioned that it is not safe to install wind turbines in areas with wind speed of

more than 11 m/s, because of the possibility of damage to the system [6]. The

exponent α is the roughness coefficient which depends on land surface characteristic

[6]. The value of α is between the range of 0.05 and 0.5 [6]. The surface roughness

values (α) determined by using Eq.(9) for different years are shown in Table 7.

In this paper, annual mean wind speeds have been calculated using the value of α at

the various heights. The variation in the wind speed with height above ground is

called the wind shear profile. Figure 8 presents the vertical wind shear profile at six

studied sites for various heights.

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

0

0.2

0.4

0.6

0.8

1

1.2

2 2.5 3 3.5 4O

bse

rve

d m

ean

win

d s

pe

ed

[m

/s]

PD

F/C

DF

Mean wind speed [m/s]

Observed PDF CDF

Page 13: Effects of Climate Characteristics on Wind Power Potential ... · Eight-year meteorological data observed at Salamis region, Northern Cyprus, from 2009 to 2016 at 10m height, are

Effects of Climate Characteristics on Wind Power Potential and Economic Evaluation… 299

Table 7. Roughness values for different years (2009-2016)

Year Mean [m/s] at 10m height roughness coefficient

2009 2.722 0.282

2010 2.690 0.283

2011 2.651 0.284

2012 2.868 0.277

2013 2.962 0.274

2014 2.700 0.283

2015 2.741 0.281

2016 2.644 0.284

Whole 2.965 0.274

Figure 8. Vertical wind shear profile at Salamis

Table 8 tabulates the resultant parameters of Weibull at various heights. As shown,

the maximum observed power density values are 131.81 W/m2 at 130m height, while

the minimum power was observed at 20m for a value of 28.24 W/m2. The wind

energy generation potential of a site is classified according to average power density

values given in [6]. Hence, this site can be considered as of power class 1, poor, [6],

which indicates poor wind energy potential. Commercial wind turbines with high

capacities (MWs) are not suitable to be used in this area. However, the available wind

energy potential of the area can be exploited using small scale wind turbines.

0102030405060708090

100110120130

2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0

He

igh

t ab

ove

th

e g

rou

nd

[m

]

Mean wind speed [m/s]

Page 14: Effects of Climate Characteristics on Wind Power Potential ... · Eight-year meteorological data observed at Salamis region, Northern Cyprus, from 2009 to 2016 at 10m height, are

300 Youssef Kassem, Hüseyin Gökçekuş, Hüseyin Çamur

Table 8. Weibull parameters and power density at various heights for year 2009-2016

Parameters 20 30 50 70 80 90 130 R2

k 8.362 8.362 8.362 8.362 8.362 8.362 8.362

0.983 c [m/s] 3.515 4.018 4.52 4.957 5.142 5.311 5.875

Mean [m/s] 3.32 3.71 4.27 4.68 4.86 5.02 5.55

WPD [W/m2] 23.75 35.48 50.51 66.62 74.36 81.94 110.91

Actual mean [m/s] 3.59 4.01 4.61 5.06 5.25 5.42 5.99

Observed WPD [W/m2] 28.24 39.43 60.03 79.19 88.39 97.39 131.81

Economic analysis of electricity generation potential

The characteristic properties of the three selected wind turbines are presented in Table

9. In this study, the annual output energy and the capacity factor of large and small

different wind turbines for the studied site were calculated using Eqs. (15) and (16).

Table 9. Characteristics of the selected wind energy turbines

Characteristics Aircon10 EolSenegal

500

Finn Wind

Tuule C

200

P10-20 EWT

DW

Hub height [m] 12 18 27 36.6 50

Rated power [kW] 10 0.5 3 20 250

Cut in speed [m/s] 2.5 2 1.9 2.5 2.5

Rated speed [m/s] 11 9 10 10 10

Cut out speed

[m/s] 32 12 - 25 25

Characteristics Enercon

E33 P-15-50

DW61-900

kW

Enercon

E53

Enercon

E82

Hub height [m] 50 50 61 70 130

Rated power [kW] 330 50 900 800 2000

Cut in speed [m/s] 2.5 2.5 2.5 2.5 2.5

Rated speed [m/s] 13 10 11.5 13 12.5

Cut out speed

[m/s] 25 25 25 25 25

Page 15: Effects of Climate Characteristics on Wind Power Potential ... · Eight-year meteorological data observed at Salamis region, Northern Cyprus, from 2009 to 2016 at 10m height, are

Effects of Climate Characteristics on Wind Power Potential and Economic Evaluation… 301

Table 10 is tabulated with the annual energy power (AEP) and capacity factors (CF)

of the wind turbines. It can be noted that the highest capacity factor is obtained in the

site with EolSenegal 500. This may be attributed to the rated wind speed of 9m/s and

time generation of 22h, which is lower than the other turbine models. In addition,

Enercon E82 wind turbine model produces the highest annual energy compared to

other models and it has the lowest capacity factor of 13%. This may be attributed to

the high turbine hub height and time generation of 10h. In general the capacity factor

is greater for the wind turbines for which the nominal speed is lower. This remark was

observed for both the large wind turbines and for the small wind turbines.

Moreover, Table 10 shows the cost of unit energy per kW h based on the PVC

method. This cost is computed using Eqs. (17) and (18). The lowest and highest

values during the studied period (2009-2016) of electricity cost are obtained in site as

0.00011$/kWh and 0.082 $/kWh using Enercon E82 and EolSenegal 500,

respectively.

Based on the capacity factor, it can be concluded that the EolSenegal 500 turbine is

cost-effective for the Salamis region and could be strongly recommended for

installation.

Table 10. Electricity production and financial indices at site

Turbine 2009 2010 2011 2012 2013 2014 2015 2016

Aircon10 Generation time [h] 10.0 9.0 9.0 11.0 17.0 10.0 10.0 10.0

AEP [MWh] 47.7 36.2 46.7 117.5 212.9 58.4 85.0 59.6

CF% 13.3 11.2 14.4 29.7 34.8 16.2 23.6 16.6

Average cost analysis [$/kWh] 3.6E-02 4.7E-02 3.6E-02 1.4E-02 8.0E-03 2.9E-02 2.0E-02 2.9E-02

EolSenegal 500 Generation time [h] 22.0 22.0 22.0 22.0 24.0 22.0 24.0 22.0

AEP [MWh] 21.4 20.5 19.9 28.7 36.0 21.3 25.8 20.3

CF% 53.9 51.7 50.2 72.4 83.3 53.7 59.8 51.1

Average cost analysis [$/kWh] 8.0E-02 8.3E-02 8.6E-02 5.9E-02 4.7E-02 8.0E-02 6.6E-02 8.4E-02

Finn Wind

Tuule C 200

Generation time [h] 24.0 24.0 24.0 24.0 24.0 24.0 24.0 24.0

AEP [MWh] 124.3 119.7 116.5 162.4 185.0 123.8 136.5 118.5

CF% 47.9 46.2 44.9 62.7 71.4 47.8 52.6 45.7

Average cost analysis [$/kWh] 1.4E-02 1.4E-02 1.5E-02 1.0E-02 9.2E-03 1.4E-02 1.2E-02 1.4E-02

P10-20 Generation time [h] 10.0 9.0 9.0 11.0 17.0 10.0 10.0 10.0

AEP [MWh] 116.8 88.6 114.2 284.3 521.3 142.9 193.9 145.9

CF% 16.2 13.7 17.6 35.9 42.6 19.9 26.9 20.3

Average cost analysis [$/kWh] 1.5E-02 1.9E-02 1.5E-02 6.0E-03 3.3E-03 1.2E-02 8.8E-03 1.2E-02

Page 16: Effects of Climate Characteristics on Wind Power Potential ... · Eight-year meteorological data observed at Salamis region, Northern Cyprus, from 2009 to 2016 at 10m height, are

302 Youssef Kassem, Hüseyin Gökçekuş, Hüseyin Çamur

Turbine 2009 2010 2011 2012 2013 2014 2015 2016

EWT DW Generation time [h] 10.0 9.0 9.0 11.0 17.0 10.0 10.0 10.0

AEP [MWh] 1460.1 1108.1 1427.9 3594.4 6515.9 1786.6 2600.6 1823.8

CF% 16.2 13.7 17.6 36.3 42.6 19.9 28.9 20.3

Average cost analysis [$/kWh] 6.7E-04 8.9E-04 6.9E-04 2.7E-04 1.5E-04 5.5E-04 3.8E-04 5.4E-04

Enercon E33 Generation time [h] 10.0 9.0 9.0 11.0 17.0 10.0 10.0 10.0

AEP [MWh] 1927.4 1462.7 1884.9 4744.5 8601.0 2358.3 3432.8 2407.4

CF% 16.2 13.7 17.6 36.3 42.6 19.9 28.9 20.3

Average cost analysis [$/kWh] 5.1E-04 6.7E-04 5.2E-04 2.1E-04 1.1E-04 4.2E-04 2.9E-04 4.1E-04

P-15-50 Generation time [h] 10.0 9.0 9.0 11.0 17.0 10.0 10.0 10.0

AEP [MWh] 292.0 221.6 285.6 718.9 1303.2 275.7 471.8 237.6

CF% 16.2 13.7 17.6 36.3 42.6 15.3 26.2 13.2

Average cost analysis [$/kWh] 4.9E-03 6.5E-03 5.0E-03 2.0E-03 1.1E-03 5.2E-03 3.0E-03 6.0E-03

DW61-900 kW Generation time [h] 10.0 9.0 9.0 11.0 17.0 10.0 10.0 10.0

AEP [MWh] 3911.1 2968.2 3700.3 9627.7 17453.4 4785.4 6965.9 4885.2

CF% 12.1 10.2 12.7 27.0 31.7 14.8 21.5 15.1

Average cost analysis [$/kWh] 2.5E-04 3.3E-04 2.7E-04 1.0E-04 5.6E-05 2.1E-04 1.4E-04 2.0E-04

Enercon E53 Generation time [h] 10.0 9.0 9.0 11.0 17.0 10.0 10.0 10.0

AEP [MWh] 2691.5 2042.6 2632.1 6278.5 12011.0 3293.2 4793.8 3361.8

CF% 9.3 7.9 10.2 19.8 24.5 11.4 16.6 11.7

Average cost analysis [$/kWh] 3.6E-04 4.8E-04 3.7E-04 1.6E-04 8.2E-05 3.0E-04 2.0E-04 2.9E-04

Enercon E82 Generation time [h] 10.0 9.0 9.0 11.0 17.0 10.0 10.0 10.0

AEP [MWh] 7300.7 5540.6 7139.6 17971.8 32579.7 8697.6 12119.8 9119.0

CF% 10.1 8.6 11.0 22.7 26.6 12.1 16.8 12.7

Average cost analysis [$/kWh] 1.3E-04 1.8E-04 1.4E-04 5.5E-05 3.0E-05 1.1E-04 8.1E-05 1.1E-04

Time frequency space using Cross wavelet transform (XWT) and Wavelet

Coherence (WTC)

The wavelet transform analysis method has been widely used in the study of climate

characteristics of different areas to investigate the meteorological variations of

variables such as temperature and wind speed [27].

Page 17: Effects of Climate Characteristics on Wind Power Potential ... · Eight-year meteorological data observed at Salamis region, Northern Cyprus, from 2009 to 2016 at 10m height, are

Effects of Climate Characteristics on Wind Power Potential and Economic Evaluation… 303

Figures 9-11 show the cross and coherence wavelet spectrum for time series of wind

speed, temperature and humidity, respectively.

It is obvious from Figure 9 that there is a high zone for the period between 8 and 16

months, implying that the two series have significant correlation for the annual period

at which the phase arrows mostly point northwest.

Figure 9. Wavelet spectrum for time series of average wind speed and temperature

Figure 10 shows the XWT and CWT for wind speed and humidity temperature (the

colour bar, scale, is the same as in Figure 9). It can be seen that the two series have

significant correlation during the annual period. However, most of the arrows point to

the west, implying that they are in phase. The change in wind speed during the year

coincides with that in wind potential power cost and electricity demand cost.

Figure 10. Wavelet spectrum for time series of average monthly wind speed and

humidity

Page 18: Effects of Climate Characteristics on Wind Power Potential ... · Eight-year meteorological data observed at Salamis region, Northern Cyprus, from 2009 to 2016 at 10m height, are

304 Youssef Kassem, Hüseyin Gökçekuş, Hüseyin Çamur

Figure 11 shows the XWT and CWT for wind speed and solar radiation. The two

series have higher correlation at the annual period with the phase arrows pointing

northwest and west.

Figure 11. Wavelet spectrum for time series of average monthly temperature and

humidity

Moreover, it is found that the coherence spectrum presents a higher zone at some

areas, similar to the case of the cross wavelet spectrum for the same data pair.

CONCLUSIONS

In the contents of this study; wind speed and wind direction data from 2009 to 2016

have been analyzed for the Salamis region in Northern Cyprus. Wind speed frequency

distributions, mean wind speed, and four distribution function parameters have been

calculated. Observed values were compared with the calculated Weibull probability

distribution results. Wind direction trends were analyzed and summarized in the form

of a wind rose graph. Also, in this study, wind turbine performance assessment and

economic analysis of selected wind turbines were examined. Moreover, a

performance study of all the wind turbines was achieved in all sites by determining

the capacity factor and the cost of unit energy (UCE) per kW h based on the PVC

method. Analysis has yielded the following conclusions;

The annual mean wind speeds for Salamis region at 10 m height were found to

be t in the range of 2 – 4 m/s.

The wind data of Salamis showed that the maximum monthly wind speed

occurs in the winter while summer season has the lowest mean wind speed. In

addition, the highest mean wind speed value with 3.74 m/s is determined in

the winter season (in 2013), while the lowest value is in the summer season (in

2016) with 2.24 m/s.

Page 19: Effects of Climate Characteristics on Wind Power Potential ... · Eight-year meteorological data observed at Salamis region, Northern Cyprus, from 2009 to 2016 at 10m height, are

Effects of Climate Characteristics on Wind Power Potential and Economic Evaluation… 305

From the results, it can be said that Salamis has poor wind characteristics.

This is shown by the low hourly, monthly and yearly mean wind speed for the

whole year.

Among all analyzed wind turbine, the highest capacity factor was found in

2013, which was 83.3% using Finn Wind Tuule C 200 wind turbine. Whereas,

the minimum is found in 2010 as 7.9% using the Enercon E53 wind turbine.

The lowest and highest values of electricity cost during the studied period

(2009-2016) are obtained in site as 0.00011$/kWh and 0.082 $/kWh using

Enercon E82 and EolSenegal 500, respectively

Wind speed, temperature and humidity are near anti-phase, implying that wind

energy and air temperature can act complementary to each other with regards

to electricity generation in the area under study.

ACKNOWLEDGMENTS

The authors would like to thank the Faculty of Engineering especially the Civil

Engineering Department and Mechanical Engineering Department of the Near East

University for their support and encouragement.

REFERENCES

[1] Baniyounes, A. M. (2017). Renewable energy potential in Jordan.

International Journal of Applied Engineering Research, 12(19), 8323-8331

[2] Azad, A., Rasul, M., Islam, R., & Shishir, I. R. (2015). Analysis of Wind

Energy Prospect for Power Generation by Three Weibull Distribution

Methods. Energy Procedia, 75, 722-727. doi:10.1016/j.egypro.2015.07.499

[3] Solyali, D., Altunç, M., Tolun, S., & Aslan, Z. (2016). Wind resource

assessment of Northern Cyprus. Renewable and Sustainable Energy Reviews,

55, 180-187. doi:10.1016/j.rser.2015.10.123

[4] Belabes, B., Youcefi, A., Guerri, O., Djamai, M., & Kaabeche, A. (2015).

Evaluation of wind energy potential and estimation of cost using wind energy

turbines for electricity generation in north of Algeria. Renewable and

Sustainable Energy Reviews, 51, 1245-1255. doi:10.1016/j.rser.2015.07.043

[5] Balamurugan, P., Muthukannan, P., & Subramanian, R. (2017). Stability

enhancement in grid integrated real time wind energy conversion system with

compensating devices. International Journal of Applied Engineering

Research, 12(14), 4571-457

[6] Ozay, C., & Celiktas, M. S. (2016). Statistical analysis of wind speed using

two-parameter Weibull distribution in Alaçatı region. Energy Conversion and

Management, 121, 49-54. doi:10.1016/j.enconman.2016.05.026

Page 20: Effects of Climate Characteristics on Wind Power Potential ... · Eight-year meteorological data observed at Salamis region, Northern Cyprus, from 2009 to 2016 at 10m height, are

306 Youssef Kassem, Hüseyin Gökçekuş, Hüseyin Çamur

[7] Mostafaeipour, A. (2013). Economic evaluation of small wind turbine

utilization in Kerman, Iran. Energy Conversion and Management, 73, 214-

225. doi:10.1016/j.enconman.2013.04.018

[8] Soulouknga, M., Doka, S., N., N., & T. (2018). Analysis of wind speed data

and wind energy potential in Faya-Largeau, Chad, using Weibull distribution.

Renewable Energy, 121, 1-8. doi:10.1016/j.renene.2018.01.002

[9] Parajuli, A. (2016). A Statistical Analysis of Wind Speed and Power Density

Based on Weibull and Rayleigh Models of Jumla, Nepal. Energy and Power

Engineering, 08(07), 271-282. doi:10.4236/epe.2016.87026

[10] Hennessey, J. P. (1977). Some Aspects of Wind Power Statistics. Journal of Applied Meteorology, 16(2), 119-128. doi:10.1175/1520-

0450(1977)016<0119:saowps>2.0.co;2

[11] Chang, T. P. (2011). Estimation of wind energy potential using different

probability density functions. Applied Energy, 88(5), 1848-1856.

doi:10.1016/j.apenergy.2010.11.010

[12] Shu, Z., Li, Q., & Chan, P. (2015). Statistical analysis of wind characteristics

and wind energy potential in Hong Kong. Energy Conversion and Management, 101, 644-657. doi:10.1016/j.enconman.2015.05.070

[13] Justus, C. G., Hargraves, W. R., Mikhail, A., & Graber, D. (1978). Methods

for Estimating Wind Speed Frequency Distributions. Journal of Applied Meteorology, 17(3), 350-353. doi:10.1175/1520-

0450(1978)017<0350:mfewsf>2.0.co;2

[14] Ouarda, T., Charron, C., Shin, J., Marpu, P., Al-Mandoos, A., Al-

Tamimi, M., … Al Hosary, T. (2015). Probability distributions of wind speed

in the UAE. Energy Conversion and Management, 93, 414-434.

doi:10.1016/j.enconman.2015.01.036

[15] Chang, T. P. (2011). Performance comparison of six numerical methods in

estimating Weibull parameters for wind energy application. Applied Energy, 88(1), 272-282. doi:10.1016/j.apenergy.2010.06.018

[16] Sathyajith, M. (2014). Wind Energy Fundamentals, Resource Analysis and

Economics. Berlin: Springer Berlin.

[17] Kaabeche, A., Belhamel, M., & Ibtiouen, R. (2011). Techno-economic

valuation and optimization of integrated photovoltaic/wind energy conversion

system. Solar Energy, 85(10), 2407-2420. doi:10.1016/j.solener.2011.06.032

[18] Ucar, A., & Balo, F. (2008). A Seasonal Analysis of Wind Turbine

Characteristics and Wind Power Potential in Manisa, Turkey. International Journal of Green Energy, 5(6), 466-479. doi:10.1080/15435070802498101

[19] Irwanto, M., Gomesh, N., Mamat, M., & Yusoff, Y. (2014). Assessment of

wind power generation potential in Perlis, Malaysia. Renewable and

Page 21: Effects of Climate Characteristics on Wind Power Potential ... · Eight-year meteorological data observed at Salamis region, Northern Cyprus, from 2009 to 2016 at 10m height, are

Effects of Climate Characteristics on Wind Power Potential and Economic Evaluation… 307

Sustainable Energy Reviews, 38, 296-308. doi:10.1016/j.rser.2014.05.075

[20] Mostafaeipour, A. (2010). Feasibility study of harnessing wind energy for

turbine installation in province of Yazd in Iran. Renewable and Sustainable Energy Reviews, 14(1), 93-111. doi:10.1016/j.rser.2009.05.009

[21] Gökçek, M., & Genç, M. S. (2009). Evaluation of electricity generation and

energy cost of wind energy conversion systems (WECSs) in Central Turkey.

Applied Energy, 86(12), 2731-2739. doi:10.1016/j.apenergy.2009.03.025

[22] Pallabazzer, R. (2003). Parametric analysis of wind siting efficiency. Journal

of Wind Engineering and Industrial Aerodynamics, 91(11), 1329-1352.

doi:10.1016/j.jweia.2003.08.002

[23] Nouni, M., Mullick, S., & Kandpal, T. (2007). Techno-economics of small

wind electric generator projects for decentralized power supply in India.

Energy Policy, 35(4), 2491-2506. doi:10.1016/j.enpol.2006.08.011

[24] Gölçek, M., Erdem, H. H., & Bayülken, A. (2007). A Techno-Economical

Evaluation for Installation of Suitable Wind Energy Plants in Western

Marmara, Turkey. Energy Exploration & Exploitation, 25(6), 407-427.

doi:10.1260/014459807783791791

[25] Gökçek, M., & Genç, M. S. (2009). Evaluation of electricity generation and

energy cost of wind energy conversion systems (WECSs) in Central

Turkey. Applied Energy, 86(12), 2731-2739.

doi:10.1016/j.apenergy.2009.03.025

[26] Adaramola, M., Paul, S., & Oyedepo, S. (2011). Assessment of electricity

generation and energy cost of wind energy conversion systems in north-

central Nigeria. Energy Conversion and Management, 52(12), 3363-3368.

doi:10.1016/j.enconman.2011.07.007

[27] Chang, T., Liu, F., Ko, H., & Huang, M. (2017). Oscillation characteristic

study of wind speed, global solar radiation and air temperature using wavelet

analysis. Applied Energy, 190, 650-657. doi:10.1016/j.apenergy.2016.12.149

Page 22: Effects of Climate Characteristics on Wind Power Potential ... · Eight-year meteorological data observed at Salamis region, Northern Cyprus, from 2009 to 2016 at 10m height, are

308 Youssef Kassem, Hüseyin Gökçekuş, Hüseyin Çamur