On Some Issues of Assessing the Efficiency of Renewable Energy Power Plants and the Share of Renewables in the World s Electricity Generation

Transcription

1 Journal of Elecrical Engineering 6 (2018) doi: / / D DAVID PUBLISHING On Some Issues of Assessing he Efficiency of Renewable Energy Power Plans and he Share of Renewables in he World s Elecriciy Generaion Pavel Pavlovih Bezrukikh Hydropower and Renewable Energy Sources Deparmen, he Naional Research Universiy Moscow Power Engineering Insiue, Russia Absrac: The paper considers some issues relaed o he evaluaion of power plans using renewable energy sources: energy efficiency, economic efficiency, he share of renewable energy in he world s elecriciy generaion. A one ime in he world here was a myh ha more energy is expended on he consrucion of wind and phooelecric power saions, han hey produce for he service life. Adherens of his myh are sill found in Russia. In response o his myh, numerous sudies have been carried ou for he manufacurers of wind urbines and phoovolaic modules. I was proved ha hese power plans spen energy on hem are produced wihin a period of less han a year and he energy consumed by hem canno be aken ino accoun, since i is renewable. The auhor showed ha power plans on organic fuel and exising nuclear plans using depleed fuel wih a coefficien less han uniy fundamenally canno compensae for he energy used during heir consrucion. In he world, he concep of he LEC (Levelized Energy Cos) produced by any power plan is widely used o esimae economic efficiency. However, he formula for deermining i, in he auhor s opinion, conains an inaccuracy, which is proposed o be eliminaed. A presen, here are differen opinions on he role of RES (Renewable Energy Sources) in he producion of elecriciy. A summary indicaor is he share of renewable energy in he world s elecriciy generaion. The deerminaion of he acual share of RES and he forecas of is growh is of significan imporance for he developmen of he world economy. The auhor shows he differences in he esimaes and suggess an approach for esablishing agreed esimaes. Key words: Energy efficiency, EPBT (energy payback ime), LEC, growh rae, weighed capaciy facor, share of RES in elecriciy producion. 1. Inroducion The paper offers a new look a he assessmen of he EPBT (energy payback ime), power plans on organic fuels. This indicaor means he ime period when he energy used o creae hem reurns. I is shown ha for fuel power saions and nuclear power plans, unlike wind, solar and hydraulic power saions, he generally acceped concep of he energy payback period is no applicable because in he process of work hey consume fossil fuels. While solar, wind and hydraulic saions and saions use an inexhausible (renewable) resource he energy of he sun. Corresponding auhor: Pavel Pavlovih Bezrukikh, professor, research fields: renewable energy sources and elecriciy. The formula for deermining he LCOE (levelized cos of elecriciy) producion a power plans, or LCOE, in he auhor s opinion, conains an inaccuracy ha significanly affecs he final resul. I is shown ha a presen here are significan differences in he esimaion of he share of RES in he producion of elecriciy in he world. To subsaniae his saemen, he auhor presens he resuls of calculaions performed by he auhor, he weighed average capaciy facor for insalled capaciy in wind, phoovolaic, bio and geohermal power plans and he producion of elecriciy by hese saions in he world, as well as he share of RES. According o calculaions, he share of RES in 2016 in he producion of elecriciy was 10.3%, and

2 86 On Some Issues of Assessing he Efficiency of Renewable Energy Power Plans and according o REN21, %. The greaes discrepancy was obained by he share of he wind farm 288. The approach mehodology proposed by he auhor allows o esablish an agreed esimae of he share of RES. 2. Energy Efficiency As is known [1, 2], he EPBT is a generalized indicaor of energy efficiency for wind, sun, waer flows, ides and waves power plans. This is he raio of he energy expended on he consrucion of he saion [E exp ], including he exracion and ransporaion of raw maerials, he producion of maerials, componens and equipmen, and hen hroughou he enire work cycle, including he decommissioning of he power plan o he average annual (over lifeime) elecriciy producion (E py ) minus he expense for own needs (E oper ). Raio of he energy is expanded for he sake of consrucion. EPBT = E eхр / (E py - E oper ) (1) or, if you neglec spending on your own needs EPBT = E exp / E py Many works have shown in paricular [1, 2] ha for EPBT wind urbines i is less han one year, and for phoovolaic saions from 0.7 o 2 years. However, his approach o he evaluaion of fuel power plans, as well as nuclear hermal neurons, canno be exended, because in he producion process, hey consume fuel, he reserves of which are depleed. For hese power plans, he formula for deermining he energy payback period will be: E Fus EPBT exp Tlife (2) E py E py where F us is he annual energy equivalen of resource used coal, oil, gas, ec. Since F us / E py = 1 / CFU > 1, hen EPBT >> T life, where CFU coefficien of fuel using T life ime life of plan. For example, aking he fuel uilizaion facor for a condensaion plan equal o 50%, we find ha he energy payback period is a leas wice longer han he service life of he saion. In oher words, a hermal and nuclear power plan wih hermal neurons will never come up heir EPBT. Hence he ineviabiliy of he gradual ransiion of world energy o use renewable energy sources. In his conex, we do no consider power saions on biomass and geohermal energy. The problem is ha, in general, hese are renewable energy resources, and for specific power plans, he resource can be depleed. 3. Economic Efficiency In he world, bu, unforunaely, no in Russia, i is quie fair o deermine he cos of produced energy for he enire lifeime [3]. There are hree varians of he name of his indicaor: LCOE (Levelized Cos of Energy), LCOE (Levelized Cos of Elecriciy), LEC (Levelized Energy Cos). Formulas for deermining LEC in differen sources differ in some nuances, bu he essence is he same. The mos common formula is given below. LEC where: n I 1 n 1 M F (1 r) E (1 r) [$/МWh] (3) I invesmen expenses in he year, M operaing and mainenance expenses in he year, F fuel expenses in year (for solar, wind, hydraulic plans, i is zero), E elecriciy generaion in he year, r he discoun rae, n he lifeime of he plan. The correcness of he above formula raises doubs, despie he fac ha i is generally acceped. The fac is ha in he numeraor he cos indicaors (I, M, F ) are divided ino (1 + r) and his is quie rue, since he subsequen coss mus be brough o he beginning of consrucion. Bu in he denominaor he generaed

3 On Some Issues of Assessing he Efficiency of Renewable Energy Power Plans and 87 elecric energy E, independen of he cos of capial, divided by (1 + r), seems compleely inexplicable. The energy produced by he power plan does no change is value depending on he ime of is measuremen. A he risk of incurring he wrah of he mighy organizaions involved in LEC calculaions, I would neverheless like o hear heir argumens. Bu he quesion arises: how o ake ino accoun in he cos of elecriciy he fac ha burning fuel disappears irrevocably, and he sun, wind, waercourses i is an eernal resource. Those circumsances should be refleced in he cos of elecriciy from fuel power saions, in addiion o cos. And even if he sociey agreed o increase he elecriciy ariff, his would no be he answer o he quesion posed below. How do we ake ino accoun he exhausion of fuel resources in he cos of elecriciy from hermal power plans? In oher words: how o esablish a correc comparison of power plans on depleed fuel and power plans on renewable energy sources? 4. Esimaion of he Share of RES in he Producion of Elecriciy in he World I is well known ha in he evaluaion of he share of RES in he producion of elecriciy in he presen and fuure, here are differen approaches o ineresed organizaions. On he one hand, we have opimisic views of various associaions for cerain ypes of renewable energy. So associaions on he sudy of wind and solar energy almos every year announce he records of inpu capaciy. On he oher hand, we have very pessimisic assessmens of a number of inernaional energy organizaions, oil and gas energy companies, alhough many of hem successfully implemen he consrucion and operaion of power plans based on RES. However, hey are exremely cauious in forecasing he share of RES. Le us consider he proposed esimaion mehod based on daa for The proposed approach o he assessmen of he exising share of renewable energy in he producion of elecriciy based on RES is as follows: a concered assessmen of elecriciy producion in he world in he reporing year or recogniion of he leading role in his maer of an organizaion in he world; deermining in each counry he insalled capaciy, he volume of elecriciy producion based on RES and for each ype of RES and forms of a weighed average capaciy facor of insalled capaciy; deerminaion of he weighed average capaciy facor of he insalled capaciy for each ype of renewable energy in he world as a whole, and elecriciy generaion based on RES in general and separae ypes; deerminaion of he share of RES and cerain species in he global elecriciy producion. So, wha are he resuls of implemening he above approaches? For elecriciy producion in he world, he auhor relies on BP daa [4], according o which he producion of elecriciy by all power plans in he world in 2016 was 24, According o REN21 [5], he share of elecriciy producion based on RES was: 4% on wind power plans or, if based on he above-menioned oal producion volume, 992 ; in biomass power plans 2% or 496, a phoovolaic saions 1.5% or 372 ; on hermodynamic, idal and geohermal REN21 0.4% or 92, and oal RES only 7.9% or 1,959. Le s consider wha happens when implemening he mehodology proposed above. In Ref. [5], daa are given on he average weighed capaciy facor for he use of insalled capaciy by coninens and regions (Africa, Asia, Cenral America and he Caribbean, Eurasia, Europe, Middle Eas, Norh America) and counries (China, India, Unied Saes) for power plans a base of he above-menioned power plans.

4 88 On Some Issues of Assessing he Efficiency of Renewable Energy Power Plans and Table 1 Tape of power Wind Solar PV Biomass Ocean, SCP, Geohermal Toal Evaluaion of RES share in elecriciy generaion in he world. Renewable power capaciy (oal) in 2016, GW 487 Elecriciy producion, Esimaion of REN21 Share of global elecriciy producion, % K hc Esimaion of auhor Elecriciy producion, Share of global elecriciy producion, % , GeoES GeoES 95 1, , Difference in esimaes For he same coninens, regions and counries, daa on he insalled capaciy are given in Ref. [6]. On he basis of hese daa, he capaciy facor of using he insalled capaciy (K hc ) in he world for cerain ypes of RES was deermined. Wih one excepion in Ref. [6] for he Unied Saes on solar PV he weighed average capaciy facor is equal o 0.19, which, apparenly, is a ypo. The auhor, according o he daa [7], where he power and he generaion of elecriciy were indicaed by he monhs of 2015 and 2016 a phoovolaic saions, deermined he weighed average capaciy facor of 0.327, which was adoped o deermine he oal K hc for he world s PV saions. The following resuls were obained for K hc : wind farms 0.3, phoovolaic saions 0.17, saions on biomass 0.75, geohermal saions 0.8. Calculaion of annual elecriciy producion (E) was carried ou according o he known formula. E = P T K hc (4) where P is he insalled capaciy, T = 8,760 hours per year. Insalled capaciy for cerain ypes of renewable energy in 2016 was adoped in accordance wih Ref. [5]: P w = 487 GW, P pv = 303 GW, P Bio = 112 GW, P Geo = 13.5 GW. The resuls of he calculaions and heir comparison wih he REN21 daa are placed in Table 1. Elecriciy producion in he world in 2016 was 24,816.4 [4]. 4. Conclusion As we see, if we ake as a basis he producion of elecriciy in he world in he amoun of 24,816.4 and he share of renewable energy in 7.9%, according o REN21, he oal producion of elecriciy based on RES in he world will be 1,959. And if, wih he same in he esimaes of he insalled capaciy by ypes of renewable energy, he average weighed capaciy facor of he insalled capaciy usage is recognized as valid, hen i urns ou ha in 2016 year 2,562 were produced on he basis of renewable energy sources and he share of RES in oal elecriciy producion exceeded 10%. And his is he milesone, which many analyss expeced o achieve in References [1] Ghenai, C Life Cycle Analysis of Wind Turbine. In Susainable Developmen: Energy, Engineering and Technologies Manufacuring and Environmen. Croaia: InTech Europe. [2] Phoovolaic Power Sysems Program Life Cycle Invenories and Life Cycle Assessmen of Phoovolaic Sysems. Inernaional Energy Agency Phoovolaic Power Sysems Programme, Task 12, Repor T [3] Levelized Cos of Elecriciy Lieraure Review. a: hp:// y_lieraure_review. [4] BP Saisical Review of he World Energy June 2017.

5 On Some Issues of Assessing he Efficiency of Renewable Energy Power Plans and 89 [Full Repor]. a: hps:// rgy-economics/saisical-review-2017/bp-saisical-revie w-of-world-energy-2017-full-repor.pdf. [5] REN Renewables Global Saus Repor. a: hp:// 99_GSR_2017_Full_Repor_0621_Op.pdf. [6] IRENA Renewable Capaciy Saisics a: hp:// Capaciy-Saisics [7] US Energy Informaion Adminisraion Elecric Power Monhly wih Daa for July a: hp://large.sanford.edu/courses/2017/ph240/enriques1/d ocs/sepember2017.pdf.