International Journal of Engineering & Technology Sciences Volume 03, Issue 06, Pages , 2015

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1 Internatonal Journal of Engneerng & Technology Scences Volume 03, Issue 06, Pages , 2015 ISSN: Evaluaton of Intensty and Structural Effects on Energy Consumpton Trend n Ngera Usng the 3-D Decomposton Model Fdels I. Abam a, Samuel O. Effom b a Department of Mechancal Engneerng, Mchael Okpara Unversty of Agrculture, P. M. B 7276, Umuaha, Ngera b Department of Mechancal Engneerng, Cross Rver Unversty of Technology, P.M.B 1122, Calabar, Ngera * Correspondng author. Tel.: ; E-mal address: olver.lytleton@yahoo.com A b s t r a c t Keywords: Structural effect, Intensty effect, Decomposton, Energy consumpton, Rebound effect. Accepted:10 December2015 The optmal utlzaton of energy resources s a hallmark of sustanable growth n both developed and developng economes of the world. Equally, the level of nteractons between the economc ndcators and how they affect energy consumpton (EC) need to be aptly understood. The latter wll create an effectve structure to balance EC and ts attendant ecologcal consequences. For ths reason, the nfluence of economc ndcators: ntensty, structural and the energy rebound effect on EC pattern n Ngera s studed. Ths ncludes the agrcultural, transportaton, and the ndustral sectors. The 3-D decomposton technque was adopted usng data from 1991 to Results obtaned shows slght energy savngs n the agrcultural sector, however, the transportaton sector wtnessed surplus n EC clmaxed by the ntensty effect. Lkewse, the rebound effect, n the agrcultural and transportaton sectors ncreased by and fold respectvely, whle the ndustral sector decreased by 41 fold. Hence, energy conservaton measures and techncal mprovements were most apparent. The study thus suggests, changes arsng from the ndustral and product structure should be lnked wth strategc modfcaton of the economc structure. Sector-wse applcaton of these changes wll enhance energy effcency, soco-economc development as well as a reducton n envronmental polluton. Academc Research Onlne Publsher. All rghts reserved. 1. Introducton The subjects of energy effcency and securty are mportant to a country lke Ngera wth fastdepletng energy resources. Ths wll enhance a sustaned economc growth especally n the constraned global eco-frendly agreement condton [1]. Optmal utlzaton of energy resources through a sustanable energy mx structure s vewed as an effectve measure to ensure energy securty [1]. At the moment, Ngera seems to have fallen nto the whrlpool of energy and power crss. A condton that has created economc mbalance and consequently slowed ndustralzaton [2]. In confrontng the country s energy challenges of producton, demand, consumpton, and assocated envronmental problems, the government n the last decades has put n place structural and fscal polces across the sectors of the economy. The polces were envsoned at provdng sustanable energy conservaton frameworks to mprove effcency n all the sectors [3-5]. The specfc objectves of the 372 P a g e

2 framework nclude (a) decrease n energy ntensty n ndustres, through applcable energy conservaton system, and (b) the ntegraton of greener energy resources lke bomass, solar and the wnd nto the overall energy mx. Studes regardng sectoral performance and EC based on economc characterstcs n Ngera are lmted n the open lterature. The avalable studes were that of [6-9] whch consdered one-dmensonal effect (actvty) on energy consumpton trend only. Addtonally, Ngera wth a complcated energy development structure needs a wder analyss n ths respect. It s apparent f the current energy trend s protracted, the country s energy settngs for long-term scenaro wll be crtcal. Gven ths stuaton, a methodcal breakdown of the structural changes n the economc sectors, as well as the energy consumpton (EC) n the past years, needs to be adequately understood. The objectves of ths study, therefore, are to evaluate the mpact of structural and ntensty changes as well as the energy rebound effect on EC n three economc sectors of Ngera (Agrcultural, Industral, and the Transportaton). Moreover, to acheve all these objectves, the study was consdered under the followng subheadngs. Frst a revew of Ngera economy (secton 1.1), methodology and model formulaton (secton 2) and fnally the results and dscusson n secton The Ngera Economy The economy of Ngera depends manly on ol that contrbutes about 98 and 80 % of the country s export earnngs and government ncome respectvely. The country wtnessed a GDP growth rate of 6.9 % between 2005 and 2012, rsng to 8.6 % n However, the GDP declned to 4.5 % n the frst quarter of 2009 due to revew n the economc polces. In 2011, the GDP was estmated at $US bllon equvalent to 0.38 % of the global economy [10]. The share of the ndustral, agrcultural and transportaton sector to the overall GDP was %, 2.64% and % n 1991, respectvely whle n 2011 the share stood at % ndustral, 1.99 % agrcultural and % transportaton. The GDPs for the three economc sectors at the 2005 current prces s presented n Fgure1 [10]. Fg.1: GDP by sector based on 2005 Current Basc Prces from [10-12] Furthermore, the analyss of the probable energy reserve n 2011 was: coal 2.7 bllon tons, crude ol 37.2 bllon barrels and natural gas 5.1 trllon cubc meters. The total energy consumpton (EC) n 2011 was calculated at 3.6 % over that n 2010 brngng the value of the aggregate consumpton to approxmately 4.4 quadrllons [11-12]. The energy consumpton profle for the three economc sectors of Ngera, ndustral, agrcultural and transportaton s presented n Fgure 2. The ndustral sector wtnessed an ncrease n energy usage from 2002 to 2008 and declned n 2009 and then ncreased slghtly by The transportaton sector fared to drop ts share to the naton s EC from % n 2008 to 9.76 % n Lastly, energy usage n the agrcultural sector dd not exceed 2.5 % n 2000, 7.5 % n 2006 but ncrease to 10.0 % n P a g e

3 Fg. 2: Energy consumpton by sector from [10], [11], [12] Also, the energy ntensty (EI) from ( ) Fgure 3 show that all the sectors experenced fluctuaton n EI over the years. EI s the amount of energy unts needed to yeld one dollar unt of economc output. The EI of the ndustral sector mproved from ktoe/us$-1000 n 1990 to ktoe/us$-1000 n Representng a growth of 8.7 % and contrbutng nearly 27.8 % to the overall EI. The EI dropped by about 30 % from 2006 to The EI values for the transportaton and the agrcultural sector decreased by % and %, respectvely from 2009 to Nonetheless, the contrbuton of the sectors to the overall EI was 3.7 %, %, and % for agrcultural, transportaton and the ndustral sectors respectvely. [10-12], for the perod between 1991 and Also, the trend of the EC n each year was modeled based on the GDP effect wth the EC at the base year. Values of the GDP and the energy consumpton of 1990 were used as the base year nputs. The complete decomposton technque was appled whch entals the decomposton of the energy consumpton (EC) nto three terms of actvty (GDP), energy ntensty, and economc structure. The decomposton of EC for economc sector as retreved from [13-14] s presented n Eq. (1). EC = GDP I S (1) Where, I and S are the energy ntensty and economc structure for sector, respectvely. From Eq. (1) the change n EC for y years can be expressed as, EC = EC y EC 0 = I y y S GDP y I 0 0 S GDP 0 (2) Where, EC 0 and EC y are the energy consumpton for the base year and y year respectvely. The EC s dvded nto the followng nfluencng ndcators: S effect, GDP effect and I effect and rewrtten as n Eq. (3) EC = I effect + S effect + GDP effect (3) Where,S effect, GDP effect, I effect denotes structural effect, actvty effect (GDP) and the ntensty effect. The three effects are further decomposed nto expressons (4) to (6) followng the method n (Sun 2001). I effect = 0 I S GDP I 2 (I GDP 0 + S 0 GDP) + 1 I 3 S GDP (4) Fg. 3: Energy ntenstes by sector from (Authors calculaton) 2.0. Methodology and Model Formulaton The net data used for the three sectors (ndustral, agrcultural and transportaton) were obtaned from S effect = I 0 S GDP S ( I GDP 0 + I 0 GDP) + 1 I 3 S GDP (5) GDP effect = I 0 S GDP GDP( I S + I 0 S ) I S GDP (6) 374 P a g e

4 2.1. Real and Trend Energy Consumpton The real EC n each sector at any gven year y expressed n Eq. (7). The trend of the EC n y year s modeled based on GDP effect wth the EC at the base year just before the year, y Eq. (8). The dfference exstng between the real and trend of EC s energy savng ψ [16] expressed n Eq. (9). A negatve value of ψ connotes less EC whle a postve value ndcates surplus n EC EC real = EC + EC 0 (7) EC trend = GDP effect + EC 0 (8) ψ = Real Trend = ΔEC GDP effect = I effect + S effect (9) In addton, energy savng (ES) and reducton n EC exst for ψ < 0 whle for ψ > 0, ES s not acheved and denotes ncrease n EC. Consequently Eq. (9) can be expressed n the expanded form by substtutng Eqs. (4) and (5) nto Eq. (9) as follows, = I S 0 GDP I 2 (S GDP 0 + S 0 GDP) + I 0 S GDP S ( I GDP 0 + S 0 GDP) + 2 I 3 S GDP (10) 2.2. Rebound Energy Effect The rebound energy effect (RE) predcts the growth that occurs f the technologcal modfcaton s not ncluded drectly. RE also evaluates the response of the sectors regardng EC to the progress of value addton and the structural effect. The decomposton breakdown has been related to sustanablty, where demateralzaton of the energy producton, the materalzaton of the energy consumpton and the rebound energy effect are consdered sgnfcant n determnng energy sustanablty. The equaton descrbng energy sustanablty [15] s expressed n Eq. (11). E De E s = ( E Sa ) = ( E Re (11) I effect ) ( S effect ) GDP effect Where, E De represents demateralzaton,e Sa s energy savng (mmateralzaton) and E Re s the rebound energy effect. Solvng Eq. (11) yelds the soluton of the matrx as, E De E s = ( E Sa ) = ( E Re 3. Results and dscusson I effect I effect S effect S effect + GDP effect 3.1. The Agrcultural Sector ) (12) Table 1 shows the yearly breakdown of the calculated economc ndcators, trend and the real EC from 1991 to 2011 for the agrcultural sector. Durng ths perod, the overall ntensty and structural effects were and ktoe respectvely. Between the years 1991 and 1992 the ntensty effect was responsble for the surplus n EC whle the structural effect was the reason for reducton EC. A careful study of Table 1 ndcates that durng 1993 to 1997 the sector conserved energy clmaxed by the ntensty effect. Smlarly, between these years the structural effect had caused the over-consumpton of energy. The changes n I effect and s effect were responsble for about 40 % of the energy conserved durng ths perod (1994 to 1998) wth values ranged between 363 I effect 900 ktoe and 159 S effect 1260 ktoe, respectvely. Consequently, n 2004 and 2005 the sector observed a margnal decrease of 0.3 % n EC. Ths reducton n EC s attrbuted to the polcy change n The varatons n EC observed between years n the agrcultural sector ndcates ncongruty n polcy mplementaton. Nonetheless, the agrcultural sector s characterzed by hgh energy expendture snce producton 375 P a g e

5 methods are subsstent descrbed by hgh human nput ntensty wth lttle-mechanzed practce. Table 1: Changes n energy and structural effects on energy consumpton n the Agrcultural Sector of Ngera ( ) (ktoe) Year Ieffect Seffect Real Change Trend The Industral Sector The effects of the structural and ntensty ndcators, as well as the trend and real EC for the ndustral sector, s presented n Table 2 from 1991 to The values exst at ktoe for I effect and for S effect. The EC trend durng these years are greater than the real EC values n some years ndcatng less EC. In addton, from 2002 to 2008 the sector wtnessed an over consumpton whch accounted for over 20 % of the total energy consumpton n ths perod. The surplus EC was trggered by the structural effect whle the ntensty effect has led to reducton n EC. The fluctuatons n the sector performance are attrbuted to 376 P a g e

6 unfavorable fscal polces, whch has strred ncreased mportaton of goods at the detrment of local producton. Also, the collapsed n most energy consumng ndustres lke cement, steel and paper ndustres, was the major factor responsble for decrease n EC. In 2004 and 2005 some economc measures were ntroduced by government ntended at mprovng the sector performance. These measures are presumed for the margnal success n the economc structure and the ntensty between 2005 and Table 2: Changes n energy and structural effects on energy consumpton n the Industral Sector of Ngera ( ) (ktoe) Year Ieffect Seffect Real Change Trend P a g e

7 3.3. The Transportaton Sector The varatons n the economc ndcators for the transportaton sector between 1991 and 2011 are depcted n Table 3. The sector wtnessed an ncrease n EC n between years. However, about % of the extra EC was due to ntensty effect whle % was due to the structural effect. From 1996 to 2000 and 2005 to 2010, the sector wtnessed a constant mprovement stmulated by the I effect. Smlarly, the S effect was responsble for the mprovement n 1993, 1994, 1997, 1998, 2001, 2002, 2007 and Smlarly, between 2005 and 2010, the trend EC > the real EC, a condton satsfactory for energy savng. The latter s ascrbed to polcy change, whch comprse the reducton n the age of farly used mported vehcles. Also, the declned n EC n the sector s assocated to the botch n the ralway structure, reducton n local ar flghts and car possesson level. Table 3: Changes n energy and structural effects on energy consumpton n the Transportaton Sector of Ngera ( ) (ktoe) Year Ieffect Seffect Real Change Trend P a g e

8 3.4. The Overall Energy Rebound Effect The total energy rebound effect (TRE) from 1991 to 2011 s presented n Fg. 4 for all the consdered sectors. The overall economy wthn ths perod wtnessed a reducton n EC of about ktoe. Moreover, the contrbutons of the ndcators, I effect, and S effect to the overall economy was % and % respectvely. The results also show that the rebound effect n agrcultural (REA) and the rebound effect n transportaton (RET) ncreased by and fold, respectvely n 2011 compared to that n 1991whle the rebound effect n the ndustral sector decreased by 41 fold. Addtonally, the contrbutons of the ndcators between 1991 and 2011 to the overall economy were 7, ktoe for S effect, and 34, ktoe for I effect. A further breakdown of the rebound effect shows that technologcal upgradng s more n the transportaton and agrcultural sectors than the ndustral sector. Snce the ndustral sector from the study was found to be the largest consumer of energy, technologcal mprovements regardng producton methods are necessary to reduce EC and ncrease effcency. Fg. 4: Overall energy rebound effect ( ) 4. Recommendatons Snce economc progresson stmulates energy consumpton, ascertanng specfc measures to cut down energy consumpton n an economy s sgnfcant. Acheved by regulatng the energy ntensty and the structural dmenson of the economy wthout compromsng the economc actvty. Adjustment arsng from the ndustral and product structure should be concomtant wth planned adjustment of the economc structure. Technologcal change wth hgh local content addressng ssues of long-term progress plannng of research and development should be a top precedence. Ths should nclude energy converson methods and end-use applcatons that requre hgh energy consumpton. Adequate dstrbuton of techncal nnovatons that enhances energy effcency should be encouraged by the government, through the provson of credt 379 P a g e

9 facltes to producton or manufacturng frms for upgradng. 5. Concluson The study presents the effect of the structural and ntensty change ndcators on three economc sectors of Ngera (Agrcultural, Industral, and Transportaton). For the transportaton sector, the structural change was responsble for the surplus n EC durng the study perod. The two ndcators I effect and the S effect has culmnated the surplus n EC observed n the agrcultural sector. Smlarly, the EC n the ndustral sector durng the study perod accounted for about 70 % of the overall EC and contrbuted prncpally to the economc progresson. Therefore, energy effcency measures are vtal n ths sector. The energy rebound effect shows that technologcal mprovement s more n the transportaton and agrcultural sector than the ndustral sector. For effectve economc growth and sustanablty, the economc ndcators must be balanced through effectve polcy and technologcal upgradng. References [1] Punyong, K, Taweekun, J, Prasertsan, S. Evaluaton of energy savng n Tha ndustry by 3- D decomposton method. The 2 nd Internatonal Conference on sustanable energy and envronment November 2006, Bangkok, Thaland. [2] Abam, F. I, Nwankwojke, B. N, Ohunakn, O. S, Ojomu, S. A. Energy Resource Structure and On-gong Sustanable Development Polcy n Ngera: A Revew. Internatonal Journal of Energy and Envronmental Engneerng 2014; 5(2):2-16. do: /s [3] ECN-UNDP. Energy Commsson of Ngera and Unted Natons Development Programme. Renewable Energy Master Plan (REMP): Fnal Draft Report, Avalable at: s/2014/08/renewable-energy-master- Plan2005.pdf. Accessed 20 February [4] FGNTP. Federal Government of Ngera Draft Natonal Transport Polcy, Avalable at: nzaton/act/262_draft%20natonal%20transport %20Polcy.pdf. Accessed 4 Aprl 2015 [5] IPON. Industral Polcy of Ngera: Targets, Polces, Incentves, Gudelnes and Insttutonal Framework, Avalable at: Accessed 18 December [6] Adegbem, B. O, Adegbem, O. O, Olalekan, A. J, Babatunde, O. O. Energy consumpton and Ngeran economc growth: an emprcal analyss. European Scentfc Journal 2013; (9)4: [7] Orhewere, B, Machame, H. Energy Consumpton and Economc Growth n Ngera. JORIND. 2011; (9)1: [8] Odularu, G. O, Okonkwo, C. Does energy consumpton contrbute to economc performance? Emprcal evdence from Ngera. Journal of Economcs and Internatonal Fnance 2009; 1: [9] Olusegun, O. A. Energy Consumpton and Economc Growth n Ngera: A Bounds Testng Contegraton Approach. Journal of Economc Theory 2008; 2 (4); [10] USEIA. US Energy nformaton Admnstraton country analyss brefs Ngera Accessed 15 June [11] NBS. Natonal Bureau of Statstcs (NBS) Annual abstract of statstcs Avalable at: Accessed 05 February P a g e

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