Wind Energy Assessment for Five Locations in Saudi Arabia

Transcription

1 202 International Conferene on Future Environment and Energy IPCBEE vol.28(202) (202)IACSIT Press, Singapoore Wind Energy Assessment for Five Loations in Saudi Arabia Hassan M. Farh, Ali M. Eltamaly, Mohamed A. A. Mohamed + Department of Eletrial Engineering, College of Engineering, King Saud University, P.O. Box 800, Riyadh 42, Saudi Arabia Abstrat.This paper introdues a omputer program to hoose the most suitable ind turbine for eah site aording to tehnial and eonomial assessment. The riterion for hoosing the most suitable ind turbine for eah site is aording to hih ind turbine and site give a maximum apaity fator and minimum ost of energy($/wh). This riterion is used beause the deision of mathing hih depends only on maximum apaity fator is not enough beause apaity fator is independent of rated poer of ind turbine. Therefore, to ind turbines ith the same performane parameters but different rated poer get the same apaity fator for the same site but it does not get the same ost of energy($/wh). The omputer program has been applied on five loations in Saudi Arabia. The five loations are Yanbou, Dhahran, Douhlom, Riyadh and Qaisumah. The ind turbine parameters suh as hub height, rated poer, ut-in, rated, and furling ind speeds for ten ommerial ind turbines are olleted. The Weibull parameters have been estimated numerially and graphially for these five loations. The values of Weibull parameters obtained graphially are similar to the numerial one. Three methods have been used for estimating the ost of energy. The results from these three methods have been ompared and the suitable one for Saudi Arabia eonomis has been seleted. Keyords: Weibull parameters; Cost of energy; Present value of ost; Yearly energy generated; Capaity fator.. Introdution Wind turbine generator, WTG harateristis are different from one to another. Also, the harateristis of the ind speed are different from site to site. Pairing beteen the performane parameters of WTG and the ind speed harateristis of eah site an inrease the ind energy aptured onsiderably and redue the ost of the generated energy. The main performane parameters of the WTG are, ut in, rated and furling ind speeds respetively and rated poer of the WTG. Also, the main harateristis of ind speed in a ertain site are the shape parameter, and the sale parameter, that an be obtained from Weibull distribution statistial tehnique. Different tehniques are used for pairing beteen sites and ind turbines. Some of these tehniques depend only on tehnial onstraints or on eonomi onstraints. But, the best tehnique for pairing beteen the performane parameters of WTG and the ind speed harateristis of eah site should depend on both tehnial and eonomi assessments. In these studies [-3], a simplified tehnique for pairing beteen sites and WTG depends only on apaity fator. This tehnique taes a deision depending only on tehnial onstraints. These studies [-3] omitted assessment in eonomi terms hih is very important in the evaluation proess, hih should be inluded the tehnial and eonomi aspet to beome reliable. On the other hand, a tehnial and eonomial assessment has been made of the generation of eletriity using ind turbines at some of the most promising ind sites in Egypt and Saudi Arabia. The value of money method has been used to determine the present value of osts (PVC) of eletriity produed per year. The eletrial + Corresponding author. Tel.: & ; fax: addresses: hfarh@su.edu.sa (Hassan M. Farh), eltamaly@su.edu.sa (Ali M. Eltamaly), betazezo_00@yahoo.om (Mohamed A. A. Mohamed) 48

2 energy ost of Wh produed as estimated by dividing the present value of osts by the total energy prodution of the ind turbine over its life time [4-7]. In this study, the hourly mean ind speed data are being olleted for five loations in Saudi Arabia for a omplete year. The five seleted loations are Yanbou, Dhahran, Douhlom, Riyadh and Qaisumah. Also, Matlab program is used to hoose the most suitable WTG for eah site aording to tehnial and eonomi assessment. This proposed program an be used to handle many other sites and many ind turbines. The Weibull parameters (, ) have been estimated numerially and graphially. Three methods have been used for estimating the ost of energy. The results from these three methods have been ompared and the suitable one for Saudi Arabia eonomis has been seleted. 2. Desription of the Main Program The flohart of the main program is shon in Fig., here tehnial and eonomial assessment have been done through hoosing the best WTG for eah site. The riterion for hoosing the most suitable WTG for eah site is aording to hih WTG and site give us maximum apaity fator,, and minimum ost of energy($/wh). The deision of mathing hih depends only on maximum is not enough beause is independent of P r. Therefore, to ind turbines ith the same u, u r and u f but different nominal poer, P r, get the same at the same site but not get the same ost of energy ($/Wh). The data input to the main program are: - The hourly mean values of the ind speed data hih olleted at 0 m height for five loations Yanbou, Dhahran, Douhlom, Riyadh and Qaissumah. 2- The parameters (P r, u, u r, u f, H) for ten WTG are olleted and extrated from Exel data file. The data output (results) from the main program are: - The estimation of eibull parameters numerially and graphially, apaity fator, the yearly energy output, average no. of WTG, and the ost of energy using three methods and omparing beteen them. 2- The best WTG for eah site aording to tehnial and eonomial assessment. START INPUT "No of sites''=i INPUT "No of WTGs"=j READ annual ind speed data for site i EstimateWeibull parameters (, ) at 0m height numerially and graphially READ WTGs(j) parameters Pr(j), u(j), ur(j), uf(j), H(j) EstimateWeibull parameters (, ) at Hub height Caulation of the apaity fator,cf(ij), using Eq.() Pe,av(ij)=CF(ij)*Pr(j) Eout(ij)=Pe,av(ij)*(time)=CF(ij)*Pr(j)*8760 alulate the average no. of the WTG (ij)=plav./pe,av(ij) alulate the ost of energy COE(ij) using Eq.(4), Eq.(5) and Eq.(6) CF=CF_max COE=COE_min If (CF(ij)=CF_max) && (COE(ij)=COE_min) No Yes Print the best WTG for this site is: j END 49

3 Fig.. the flo hart of the main Matlab program. 3. Mathematial Analysis 3.. Weibull Parameters Estimation The ind speed, u is distributed as the Weibull distribution if its probability density funtion is [8] u u f ( u ) = exp ( f 0, u f 0, f ) And the umulative distribution funtion an be estimated by integrating Eq. () u u F ( u) = f ( u) du = exp (2) 0 F(u) ontains an exponential as in Eq. (2) and that, in general, exponentials are linearized by taing the logarithm. In this ase, beause the exponent is itself raised to a poer, e must tae logarithms tie [4-6, 8]. ln[ ln( F ( u))] = ln u ln (3) This equation taes the form of straight line as shon: y = ax + b (4) The values of a and b an be determined as follo: a = xi y i i= i= xi yi ( xi x) ( yi y) i= i= i= a =, b = y 2 i axi = yi 2 ( xi x) i= i= xi i= 2 i= xi i= In these equations x and y are the mean values of x i and y i, and is the total number of pairs of values available. The final results for the Weibull parameters are: b = a, = exp (6) Or by plotting ln u against ln[ ln( F( u)) should yield a straight line. The slop of the line is and the interept ith the y-axis is ln.then, the Weibull parameters values an be estimated at any desired height (z h ) in meter, based on the reords at the standard anemometer height of 0m by the folloing equation [6]: zh h = 0 * 0.088* ln 0 (7) n z h 0 * (8) h = 0 n = *ln( )] (9) [ 0 Where n is the poer la exponent (oeffiient). Weibull parameters have been estimated numerially for the five sites as shon in table () and graphially for Yanbou as shon in Fig.2. The values of, obtained graphially are nearly similar to the numerial one. Table (): Estimation of the Weibull parameters (, ) at 0m height. Sites Numerially Graphially x i () (5) 50

4 Yanbou Dhahran Douhlom Riyadh Qaissumah ln[-ln(-f(u))] ln[-ln(-f(u))] = 2.249*ln(u) =2.249 =5.885 data linear ln(u) Fig. 2. Plotting ln(-ln(-f(u))) against ln(u), for Yanbou as one from these five sites, through hih, are estimated Energy Prodution and Capaity Fator The yearly energy prodution of the turbine an be estimated using the folloing equation: E = P (time) = C * P *(8760) (0) out e, ave F er Where is the apaity hih an be obtained from the folloing equation [8]: F [ ( u / ) ] exp ( ur / ) ( u / ) ( u / ) r [ ] [ ( u ) ] exp C = exp / () The average number of WTG, required is given by the folloing equation: PLav = (2) P 4. Eonomi Analysis e, ave There are several methods available for estimating the ost of energy [4-8, 0-5]. In this study, the ost of energy has been estimated using three methods as follo: In method, the simple equation for getting the prie of the hole system is [9]; Total Prie = (*P r *Prie of eah KW of WTG+ O&M prie) (3) The prie of eah Wh=Total prie*lf /(E out * Availability of WTG) (4) Where P r : the rated poer of the WT, E out : the atual yearly energy output, LF :the levelization fator. In method 2, the value of money method has been used to determine the present value of osts (PVC) of eletriity produed per year given by Lysen [0] and referred by Habali [-2], Sarar [3], Alnaser [4], Türosy [5], Rehman [7] and by Shata[4-6]. PVC method used under the folloing assumptions: The life time of the mahine (t ) as assumed to be 20 years. The interest rate ( r ) and inflation rate (i ) ere taen to be 8% and 6%, respetively. Operation maintenane and repair ost ( C ) as onsidered to be 25% of omr the annual ost of the turbine (mahine prie/life time). Srap value S as taen to be 0% of the turbine prie and ivil or. Investment ( I ) inludes the turbine prie plus its 20% for the ivil or and other onnetions. The present value of osts (PVC) is [4-6, -5]: t t + i + i + i PVC = I + C omr S r i (5) + r + r The eletrial energy ost of Wh produed in eah region as estimated by dividing the present value of osts by the total energy prodution of the ind turbine over its life time (20 years). In method 3, the ost of energy, COE, is alulated using the folloing equation [6-7]: f 5

5 FCR * ICC + LLC + O & M COE = AEP net + LRC Where COE: Cost of energy, FCR: fixed harge rate, ICC: initial apital ost, AEP net : net annual energy prodution, LLC: land lease ost, O&M:operating& maintenane ost, LRC: levelized replaement/overhaul ost. 5. Results and Disussions In this study, five sites in Saudi Arabia have been seleted. The five sites are Yanbou, Dhahran, Douhlom, Riyadh and Qaissumah. The hourly ind speeds of these sites are olleted here the annual ind speed are used for eah site. The ind site harateristis (, ) are estimated graphially and numerially using Matlab program as shon in table () and Fig.2. Ten types of the ommerially available WTGs are used from various manufaturers. The tehnial data of WTGs shon in Table (2) are obtained from [8]. The loads are assumed to be the same in eah site and have MW as a maximum value. The annual average loads are used to find the average number of WTG required. Tehnial and eonomial assessments have been done through the sequene of this program. First, the ind site harateristis (, ) at hub height and the average number of WT, have been estimated as shon in table (3). Seond, the COE ($/Wh)using three methods and the for eah site and eah WTG have been done as shon in table (4), table (5) and table (6). Finally, the WTG hih has maximum and minimum COE ($/Wh) is the best one for this site. Aording to this ondition, the best WTG for all sites is (AW3000-6). For Yanbou, the maximum and minimum COE are and 0.05($/Wh). For Dhahran, the maximum and minimum COE are 0.5 and 0.058($/Wh). For Douhlom, the maximum and minimum COE are and 0.065($/Wh). For Riyadh, the maximum and minimum COE are and ($/Wh). For Qaissumah, the maximum and minimum COE are 0.34 and ($/Wh). Fig.3 shos and COE ($/Wh) of ten WTG and five sites in Saudi Arabia. Table (2): The tehnial data of WTGs (6) No. Manufaturer Model P r () D (m) u u r u f H(m) Gamesa G28/4500 4, Nordex N00/2500 2, AW-70/500, AW-82/500, AW , AW , M4 3, M04 3, MM00, GE Energy.5xle, Table (3) The Weibull parameters at hub height of eah WTG and for eah site Yanbou Dhahran Douhlom Riyadh Qaissumah Manuf. Gamesa Nordex

6 GE Energy Table (4): The yearly energy output, apaity fator and ost of energy ($/Wh) for Yanbou and Dhahran Yanbou Dhahran Manuf. Gamesa Nordex GE Energy E out *0^ COE() COE(2) COE(3) E out *0^ COE() COE(2) COE(3) Table (5): The yearly energy output, apaity fator and the ost of energy ($/Wh) for Douhlom and Riyadh Douhlom Riyadh Manuf. Gamesa Nordex GE Energy E out *0^0 COE() COE(2) COE(3) E out *0^9 COE() COE(2) Table (6): The yearly energy output, apaity fator and the ost of energy ($/Wh) for Qaissumah COE(3) Qaissumah Manuf. Gamesa Nordex E out *0^ COE() COE(2) COE(3) GE Energy

7 Fig. 3 The apaity fator and ost of energy for ten WTG and five sites in Saudi Arabia. 6. Conlusion In this study, the Weibull parameters have been estimated numerially and graphially for five sites in Saudi Arabia. The values of, obtained graphially are similar to the numerial one. Tehnial and eonomial assessments have been done using Matlab program to hoose the most suitable WTG for eah site. It as found that the most suitable WTG for the five sites is (AW3000-6) hih has maximum and minimum COE. For Yanbou, the maximum and minimum COE are and 0.05($/Wh). For Dhahran, the maximum and minimum COE are 0.5 and 0.058($/Wh). For Douhlom, the maximum and minimum COE are and 0.065($/Wh). For Riyadh, the maximum and minimum COE are and ($/Wh). For Qaissumah, the maximum and minimum COE are 0.34 and ($/Wh). Three methods are used for estimating the COE. Both of the seond (using PVC) and third (COE) ones are preferred and more aurate beause these to methods tae into aount all parameters affet the ost of energy suh as investment ost, apital osts (interest rate and repayment of loan), land replaement/lease osts and the operation /maintenane osts. But the best method for Saudi Arabia eonomis is the seond (using PVC) beause the third method (COE) taes into aount the land replaement/lease osts hih an be negligable in Saudi arabia and beause of the vast land available in Saudi Arabia. 7. Anoledgements The authors anoledge the National Plan for sienes and Tehnology program (Projet No.: 08- ENE226-02) by King Saud University for the finanial support to arry out the researh or reported in this paper. 8. Referenes [] Ssu-yuan Hua and Jung-ho Chengb. Performane Evaluation of Pairing beteen Sites and Wind Turbines. Reneable Energy, 2007; 32: [2] Pallabazzer R. Provisional Estimation of the Energy Output of Wind Generators. Reneable Energy, 2004; 29: [3] L. C. Rodman, R. K. Meentemeyer. A Geographi Analysis of Wind Turbine Plaement in Northern California. Energy Poliy Journal, 2006; 34: [4] A.S. Ahmed Shata, R. Hanits. Evaluation of ind energy potential and eletriity generation on the oast of Mediterranean Sea in Egypt. Reneable Energy, 2006; 3: [5] A.S. Ahmed Shata, R. Hanitsh. The potential of eletriity generation on the east oast of Red Sea in Egypt. Reneable Energy, 2006; 3:

8 [6] A.S. Ahmed Shata, R. Hanits. Eletriity Generation and Wind Potential Assessment at Hurghada, Egypt. Reneable Energy, 2008; 33: [7] Rehman S, Halaani TO, Mohandes M. Wind poer ost assessment at tenty loations in the ingdom of Saudi Arabia. Reneable Energy, 2003; 28: [8] Gary L. Johnson. WIND ENERGY SYSTEMS. boo, Prentie Hall In., ENGLAND liffs, 200. [9] H. H. EL-Tamaly, M. Hamada, Ali. M. EL-Tamaly. Computer simulation of ind energy system and appliations. System analysis, Control &Designs, 995; 4: [0] Lysen H. Introdution to Wind Energy. Consultany Servies, Wind Energy, Developing Countries (CWD), 82-, May, 2nd Edition, The Netherlands, 983, p [] Habali SM, Hamdan MAS, Jubran BA, Zaid AIO. Wind speed and ind energy potential of Jordan. Solar Energy, 987; 38(): [2] Habali SM, Hamdan AS, Jubran BA, Zaid AIO. Assessment and appliations of ind energy in Jordan. Solar Energy, 988; 40(2): [3] Sarar M, Hussain M. The potential of ind eletriity generation in Bangladesh. Reneable Energy, 99; (5): [4] Alnaser WE. Assessment of the possibility of using three types of ind turbine in Bahrain. Reneable Energy, 993; 3(2-3): [5] Ferdi Türsoy. Investigation of ind poer potential at Bozaada. Turey. Reneable Energy, 995; 6(8): [6] L. Fingersh, M. Hand, and A. Laxson. Wind Turbine Design Cost and Saling Model. National Reneable Energy Laboratory, Tehnial Report, NREL/TP , Deember [7] J. F. Manell and J. G. MGoan. WIND ENERGY EXPLAINED: Theory, Design and Appliation. Boo, British, ISBN (Hb), [8] Wind turbines and ind farms database. Available from 55