Wind energy potential in Karnataka, India. Ramachandra T.V.* and Shruthi B.V.+. *Energy Research Group, Centre for Ecological Sciences, Indian Institute of ...
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Cut-in note Wind energy potential in Karnataka, India Ramachandra T.V.* and Shruthi B.V.+ *Energy Research Group, Centre for Ecological Sciences, Indian Institute of Science, Bangalore 560 0 12, India E-mail: ; +Centre for Sustainable Technologies (ASTRA), Indian Institute of Science
ABSTRACT F or securing maximum output of power using a given ty pe of wind electric g enerator, an assessm ent of the wind resource available at any prospective site is essential. E stim ation of wind pow er potential is based on data of the wind frequency distribution at the site, are collected from official meteorological data. T he analy ses show that coastal and dry arid zones in K arnatak a have g ood wind potential.
1. INTRODUCTION W ind energy comm erce is one of the fastest-grow ing and economic energy sectors in the w orld [1, 2]. H owever, the w ind resource is g overned by the clima tology of the region concerned a nd has larg e va riability in location and season. H ence, the need to conduct w ind resource survey s for ex ploiting w ind energy, as below for K arnatak a, India.
2. METHODOLOGY The State of K arnatak a in w estern central India is approxima tely w ithin latitudes 11` 31’ and 18` 45’ North and longitudes 74` 12’ and 78` 40’ East; see. Figure 1 w ith the different ag roclimatic zones. K arnatak a is situated on a tableland w here the Western and Eastern G hat ranges converge into the Nilgiri hill complex . K arnatak a ’s total land area is 191,791 sq. k m. It accounts for 5.35% of the total a rea of the country and rank s eighth in size am ong m ajor States. F or administrative purpose the State is divided into 27 districts, w hich are sub divided into 175 taluks. K arnatak a is divided into 10 agroclimatic zones, considering tex ture, depth and physiochemical properties of soil, rainfall, elevation, topography, major crops a nd ty pe of vegetation. The zones a re (1) Northeastern Transition, (2) Northeastern D ry, (3) Northern D ry, (4) Central D ry, (5) Eastern D ry, (6) Southern D ry, (7) Southern Tra nsition, (8) Northern Tra nsition, (9) Hilly zone, and (10) Coastal. It is customa ry to avera ge the w ind speeds during each hour a nd use the hourly mean w ind speed a s the basic param eter in calculations of w ind power. The relationships between annual m ean wind speed (at anemom eter height of 10 m ) a nd potential value of the w ind energ y resource as considered in India are listed in table 1.
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Figure 1.
C U T- I N N O T E : W I ND E NE R G Y P O T E N T I A L
Study area with A gro climatic Zones
IN
K A R N A TA K A , I ND I A
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Table 1. Relationship between annual mean wind speed and wind energy potential Annual mean wind speed @ 10 m Height Indicated value of wind resource < 4.5 m/s Poor 4.5 – 5.4 m/s Marginal 5.4 – 6.7 m/s Good to Very Good > 6.7 m/s Exceptional In locations w here data are not available, a qualitative indication of a high annual mean w ind speed can be inferred from g eographical location, topographical features, w ind-induced soil erosion, and deformation of v egetation. H owever, accurate determination of the mean annual w ind speed requires anemom eter data for at least 12 months. Availability of wind energy and its characteristics have been studied for 45 locations in K a rna tak a based on prim ary data a t selected locations and data collected from the m eteorological observatories of the India Meteorological D epartment (IMD), w here 3-cup anemom eters with 127 m m diameter conical cups, in conformity w ith international pra ctice, are used. A nemom eters at different meteorological stations are normally at 10 m height, but if at a different height the data are adjusted to 10 m by the IMD a ccording to methods of .the World Meteorological Org anization. Since m odern w ind turbines have hub heights g reater than 10 m, w e ex trapolate to 30 m above g round using equation 1. k
v = vo [h/h o ]
(1)
W here, v : w ind speed at height h (m/ s), v o: wind speed a t anemometer height ho (m/ s), h = height at w hich w ind speed is m easured m), h o: anemometer height (10 m ), k = height ex ponent (0.14) W ind energy conversion sy stems w ould be m ost effective in these locations during May to A ugust. The Energy Pattern F actor (EPF ) and Power densities a t 30 m a re computed for sites w ith hourly wind data. W ith the k nowledge of EPF and mean w ind speed, m ean power density is computed for the locations w ith only hourly m onthly data. W ind power density of a stream of air w ith density d moving with a v elocity v m is given by, 3
P= KEm d vm / 2
(2)
W here, K Em is the energ y Pattern factor. 3
KEm = (åvi / Nm ) / vm
3
(3)
W here, v i : Hourly wind speed during the m onth, Nm : number of hourly w ind speed values during the month, and v m : monthly m ean w ind speed. F or a R ayleigh distribution of w ind speed, K Em = 1.91. Values of K Em varies from 1.05 (Jogimatti), 1.33 (Chik k odi) to 1.44 (G okak , K hamk a rtti)
3. RESULTS AND DISCUSSION W ind potential a naly sis a cross a g ro-clim a tic zone confirm s the role of g eogra phic, topographic a nd meteorological characteristics of a location to w ind speed variability. Table 2 lists locations in the respective ag ro-climatic zones with m ean w ind speed greater than 18 k m
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C U T- I N N O T E : W I ND E NE R G Y P O T E N T I A L
IN
K A R N A TA K A , I ND I A
per hour (i.e. > 5 m/ s) [4]. A m ong these sites, w ind energy g enerators totaling a capacity of 3.5 MW have been functional since 1998-99 at Chik odi. Figure 2 depicts m onthly variations a cross Northern dry zone
Table 2. Wind monitoring stations with annual mean wind power density Location Latitude Longitude Wind speed at 30m, m/s Arasinagundi 14°29’N 76°50’E 7.5 B.B. Hills 13°26’N 75°45’E 7.7 Chikkodi 16°20’N 74°30’E 6.5 Godekere 13°20’N 76°40’E 5.5 Gokak 16°07’N 74°47’E 5.9 Gujannur 14°58’N 75°54’E 6.5 Hanamsagar 15°54’N 76°02’E 6.1 Hanumanhatti 15°55’N 74°43’E 6.1 Horti 17°05’N 75°40’E 5.6 Jogimatti 14°10’N 76°22’E 8.7 Jogimatti 14°11’N 76°25’E 8.6 Khamkartti 15°45’N 74°35’E 5.8 Kahanderayanahalli 14°30’N 75°45’E 5.6 Madekeripura 14°13’N 76°27’E 7.5 Malgatti 15°52’N 75°55’E 6.1 Sangundi 16°15’N 75°44’E 5.7 Sogi A 14°55’N 75°59’E 7.4 Sogi B 14°54’N 75°59’E 6.8
Figure 2.
(> 150 W/m2) Power Density, W/m2 458 468 264 155 168 184 173 165 173 498 493 159 183 244 156 153 200 184
Monthly variation of wind velocity in Northern Dry Zone
4. CONCLUSIONS Initial analy ses of w ind speed across the ag roclimatic zones show that Northern dry zone in K arnatak a has g ood w ind potential, w hich if ex ploited w ould help local industries and ag riculture. These initial tabulations can be used for preliminary stra tegic w ind power planning, to be followed by detailed study at proposed sites.
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Cheremisinoff N.P., (2003) Fu ndam ental s of wind energy , in: A l-Moham ad, A ., K arm eh, H , W ind energy potential in Sy ria , R enewable Energ y, Vol. 28, No. 7, pp. 1039-1046.
2.
Milborrow, D ., Tishler, C., Harrison and L., O’Bryant, M., (2003) T he Windicator, in: Junginger, M., F a aij, A ., Turk enburg, W.C, Global ex perience curves for w ind farm s, Energy Policy. http:/ / w w w.sciencedirect.com (In Press).
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R am achandran A ., (2002) Teri Energ y Data Directory & Year book – 2001-2002, TER I, New D elhi, India.
