Time of Day Taiff Stuctue Omka S. Pawaska and Pof. Ms. Swati. S. Moe "./ ".- - Demand - Abstact-The demand fo electicity in ndia is inceasing evey day. As pe consume demand, utility is equied to geneate, tansmit. and distibute electicity among diffeent consumes, The cost incued by utility fo this pupose is ecoveed fom diffeent consumes by applying a suitable taiff. Load cuve of ndian utility is peaky in moning and evening hous. Diffeen~al between demand and supply is inceasing day by day. Natually cost of geneation will also incease in ode to meet the peak demand. To educe this diffeence it is necessay to shift the load of cetain consume categoies to off peak hous. The majo load on utility system is industial, and hence if industies would take initiatives fo flattening the load cuve by shifting thei loads fom peak hous to off peak hous, it will be pofitable to both,",utility and industy. To motivate consumes towads this goal is a.hallenging task. Design of 'Time of the Day' (ToD)! 'Time of Use' (ToU) taiff stuctue fo industial consumes encouages consumes to shift thei enegy usage. Unde ToD taiff, consumption duing diffeent hous (peiod) of the day is chaged diffeently. 'Mahaashta electicity egulatoy conunission' has implemented this type of taiff fom yea 2000 to diffeent industial consumes. The 'Ministy of Powe' has also pointed _ out in national policy about ToU taiff, but it is obseved that all the consumes ae not awae about this type of taiff stuctue. This Pape investigates the concept, implementation, and impact of Tune of Day taiff and othe taiff based incentives / disincentives. The pape coves specifically following points 1. Detail study of ToD taiff stuctue applied to diffeent industial consumes and its effect in Mahaashta. 2. Study of diffeent incentives! disincentives given to these consumes such as powe facto incentive, load facto incentive, powe facto penalty etc. 3. Appoach of egulatoy conunission in Mahaashta as well as at national level towads this taiff stuctue..: "ndex Tems-Time of Day taiff, Demand Side Management, taiff incentives and disincentives, Mahaashta Electicity Regulatoy commission, Mahaashta.. NTRODUCTON of electicity is inceasing evey day. Also thee is lage vaiation in demand at diffeent time peiods of the day. The load cuve of ndian utility nomally has moning peak and evening peak. Diffeential between demand and supply is inceasing day by day. n this scenaio, in ode to meet peak demand, if geneation capacity is inceased, the cost of O. S. Pawaska is PG student of Bhaati Vidyapeeth Univesity College of Engg, Pune.lndia (e-mail: omka73@gmailcom). Ms. S. S. Moe is with the Depatment of Electical Engineeing, Bhaati Vidyapeeth Univesity, Pune, ndia (e-mail: ssmoe@gmailcom).. geneation will also incease. n an existing shotage situation in Mahaashta, the peak powe available is significantly costlie than off peak powe and availability of powe duing peak hous is also limited. Fo.educing the cost of geneation, it is necessay to educe buden on the system and hence steps ae to be taken fo flattening of the load cuve i.e. to distibute the load (powe demand) evenly though out the time peiod of the day. n ode to encouage the consumes to take active pat in load shifting (load cuve flattening) technique, some demand side management. DSM) pogams ae equied to be implemented. DSM involves co-opeative action by the utility and consume to modify the consume load cuve esulting.in savings to the consume, utility and society. Also load leveling would esult in impoved capacity utilization. Load leveling could. be pomoted by use of one of taiff. elated DSM options like time of day! time of use taiff (ToDlToU) in which consumption duing diffeent hous (peiod) of the day is chaged diffeently. The majo load on utility is industies and hence industies have to take majo pat fo flattening the load cuve. ToD taiff stuctue is hence implemented fo industial consumes of Mahaashta State Electicity Boad (MSEB) since yea 2000 unde diectives by the Mahaashta Electicity egulatoy commission (MERC). Switching fom flat ate taiff to ToD taiff, it is possible to have educed electicity bill povided industies take benefit of this taiff stuctue by suitably modifying thei load patten. MERC also povides them some i~centives such as powe facto incentive, load facto incentive etc. and some disincentives such as powe facto penalty. n ode to educe cost of powe and t() ceate awaeness among consumes about such taiff stuctue, it is necessay to study oveall philosophy behind ToDlToU taiff stuctue. The pape specifically coves the taiff stuctue fo HT industial consumes unde Mahaashta State Electicity Distibution Company Ltd (MSEDCL), which is the successo entity of MSElt The pape descibes the concept, implementation, and' impact of ToD taiff on utility's load cuve, appoach of egulatoy commission towads this taiff stuctue specifically in Mahaashta and at national level... TaD A KEY DSM OPTON Load cuve of the ndian utility vaies fom diffeent time peiods of the day. A typical load cuve of Mahaashta state unde MSEDCL dated 9 th Octobe 2007 (andom sample) is shown in.fig 1. [l3] ~\. E() 23d National Convention of Electical Enginees /119..
l 16000 14000 312000 :: ~10000 i,..- -g 8000 E 6000 i e! 4000 2000 0,.- i...-- 1--, ~ t- ' j; ::j i --.. i:!:' i~,- ".. - " '\ : i,,- /'- o,/ Load Cuve 3 5 7 9 11 13 15 17 19 21 23 Time of Day Fig.. Load Cuve of Mahaashta state (andom sample selection of nomal woking day) To evaluate the effect of DSM on consumes as well as on MSEB. in 1992-94 yoti K Paikh et al conducted a detailed study of HT industies and taiff stuctue in Mahaashta [1]. Based on the esults of this HT consume suvey they had pointed out that if peaking powe geneation plants ae built they emain idle fo the off peak peiods and do not. ean etuns duing those hous. Hence the cost of this option to educe the peak load should be taken in account befoe building such plants. Altenatively shifting peak load to off peak hous can poduce desied esult. This can be done by some DSM options in which one of the options is ToOl TaU taiff. The esults of the suvey shews that if DSM pogams ae implemented, utility saves money in tems of opeating costs of fuel fo powe geneation and investments ae saved though educed new capacity equiements. Out of all DSM pogams consideed in the above study, ToD was found to be the majo contibuto in savings. They also pointed out in suvey esults that the taiff needs to deal with at least eight hous duation of off-peak hous and not moe.than.thee.to fou hous of peak peiod. A suggestion was made by the goup that the maximum demand chages should eflect the cost of demand at least in peak peiod and theefoe thee should be diffeent demand ates fo diffeent time peiods [1]. As discussed late, MERC has howeve kept the demand chages same fo all the time peiods of the day. Results of the suvey also show that due to implementation of this taiff to industial consumes, industies would get educed electicity bill, Some industies could shift thee poduction in night time peiod, and shift industies who have thei poduction in two o thee shifts, could change thei shift timings in ode to get ToO taiff benefit in thei electicity bill. Results futhe show that if sufficient incentives ae povided to them, and if some awaeness pogams ae aanged then moe amount of load can be shifted fom peak to.. off peak time peiod. Load leveling would esult in impoved capacity utilization and also esults in sufficient flattening of the load cuve. Fom thei analysis, they found out that by the yea 2012, DSM pogam to consumes would save 2,235MW. of powe out of which 761MW powe can be saved due to TaD taiff which acc~nts fo one thid of the saving i.e. 34.1% of total saving. Simila to yoti K Paikh e diffeent suveys, analytical studies and epesentation ca found in liteatue to detemine the effectiveness of ToD t stuctue. National electicity policy in its section 5.4.9 section 5.9.6 also ecommends fo Time of the Use t stuctue fo HT consumes in ode to educe equiements fo capacity additions. Policy also pointed that, as the diffeence between electical powe demand du peak peiods and off-peak peiods would have to be edu suitable load management techniques should be adopted this pupose. [12] ll. TOD TARFF N MAHARASHTRA Constuction of new powe geneation plants and suppl the powe at easonable cost ae the limiting factos of Su Side Management and hence Mahaashta Elect Regulatoy Commission (MERC) had in anncip: intoduced ToD taiff stuctue fo the fist time in the cou to all HT industial consumes unde MSEB since yea 20( n this type of taiff stuctue, MERC had intoduce 5 slots of a day in which units fo diffeent time peiods 0 day will be chaged at diffeent ates. Commission intoduced some chages along with base chages in this design. t means that along with the base ate taiff fo pe powe consumption thee is some concession povide commission fo evey unit powe consumption in night peiod fom 10 pm to 6am (off peak time). and use of p duing moning and evening time peiods i.e. fom 9 am 1 pm (moning peak) and 6 pm to 10 pm (evening p industies would have to pay exta chages fo each un emaining time span, ates ae base ates. This type of stuctue would encouage the industies to shift thei fom moning and evening peaks to off peak time peiod to get them educed electicity bill and also to getn flatten-lead-cuve. {11] While implementing this type of taiff fo HT consul commission adopted following appoach: HT taiffs pio to financial yea (FY) 2000 wee h than the aveage cost of supply theefoe. in ode to bin taiff close to the aveage cost of supply; HT taiffs equied to be educed. The aveage HT taiff (compi both demand and enegy chages) was highe than the c( supply, and the demand chages do not eflect the fixed incued in supplying electicity and the enegy chages consideably highe than the vaiable cost of electicity s: hence the commission had stated diffeent taiff compo with thei espective costs. Accodingly thee was ince: demand chages while decease in enegy chages fo a consume categoies. [2] To estuctue HT taiff, the commission intended t 'ToD' taiff as a citical tool fo DSM Commission expected HT industial consumes to av this facility by shifting consumption fom peak to off peiod. This would not only be beneficial fo industie also helps the MSEDCL in flattening the load cuve. The incease in demand chages inceases the E() 23d National Convention of Electical Enginees /120
(- ~ j " ),- electicity bill of the consumes hence commission helped the industial consumes in shifting the demand and in flattening the demand cuve. Theefoe, the Commission had decided and evised the definition of billing demand. t is seen that vaious lage scale industies ae going fo captive powe geneation, as well as some consumes enteed in to open access. This ceated pessue on commission as well as on utility to lowe the taiff so as to attact moe numbe of consumes towads MSEDCL Towads the implementation of the ToD taiffs commission has inceased the diffeence in the ToD ates fom peak and off-peak times fo the HTP- and HTP- categoies. [4]. [5] The commission had initiated the pocess of levying a 'Reliability Chage', on TP- and TP- consumes who have been povided with ToD metes, fom 2004 taiff ode. [4] Along with implementation of ToD taiff to HT consumes, commission also povided them some incentives such as powe facto and load facto incentives and disincentives such as powe facto penalty. Some of them as applicable in taiff ode 2007-08 ae descibe as follows': A. Powe facto incentive Wheneve the aveage powe facto is moe than 0.95, an incentive given is at the ate of 1% of the amount of the monthly enegy pill (excluding Fuel adjustment cost, demand chage. and electicity duty) fo evey 1% impovement in the powe facto above 0.95. Fo PF of 0.99, the effective incentive amounts to 5% eduction in the enegy bill. Fo unity and leading PF effective incentive would be maximum 7% eduction in the enegy bill. [6] B. Loadfacto incentive Consumes having load facto in between 0.75 to 0.85 ae entitled to a ebate of 0.75% on the enegy chages fo evey pecentage incease in load facto fom 0.75 to 0.85. Consumes having a load facto above 0.85 ae given a ebate of 1% on the enegy. chages fo evey pecent incease in load facto fom 0.85. The total ebate fo this is subjected to a maximum of 15% of the enegy chages fo that consume. This incentive is limited to lt- categoy only. [6] C. Powe facto penalty Wheneve the aveage PF is. less than 0.9. penalty chages shall be levied at the ate of 2% of the amount of the monthly bill including enegy chages. fo the fist 1% fall in the powe facto below 0.9. beyond which the penalty chages shall be levied at the ate of % fo each pecentage point fall in the PF below 0.89. [6] Consequences of such taiff stuctue appea to eflect on consumption patten. e.g. in yea 2004 HT industies have achieved the nomative patten whee as the othe categoy co~umes show that the load needs to be flattening futhe to match nomative level. Gaphical epesentation of these obsevations is self explanatoy. '. [4] ToO Consumption Patten 45.00%,.,...,==~""",~=,...,-~".,..,...,...,~~7."1"~-:-:-' 4o.00%-..;;~~~:;,;::t..;",,:w.i::;;:"';:':';:':"';';";:...-'.;""':;;;;;;:;"~;;:;:"';";"""~ 2200-0600 00)).()900 & 1200 11m... "., ~.~'...:~{~:.;.:~, (Y.H.).1200 18(..2200 -+-HlPi&1 32,45% 38.47% 12.42% 16.66% --HlPUU 32.75% 38.55% 1245% 16.23% f---o!!leht 29.13% 42.33% 12.~ 16.16% lll.g 27.78% 41.74% 15.18% 15.~ i-w->.bm'l!!ye 33.33% 37.5O'A. 12.50% 16.67% Fig. 2. ToO consumption patten The commission. by administeing pogessive incease in diffeential. between peak and off peak taiffs, ove the yeas has bought the desied change. The Commission has made ToD taiff mandatoy fo industial consumes' categoy since 2004 taiff Ode and hence theeafte all lt industial consumes unde MSEDCL have been billed with ToD taiff only. [4] Following gaph shows that, the diffeence in peak to off peak enegy has inceased fom 1.5 to 2.5. Peak Peiod/Off Peak Peiod Vs,: 2.5 0.5 Yeas 2000-01 2001..02 2003..05 2006..07 2007..08 Yeas Fig. 3. Gaphical epesentation of taiff odes Vs peak to off peak atio [2), (3), [4), (5); [61 D. Compaison of taiff ates fom diffeent taiff odes The lt consumes of diffeent types such as continuous and non-continuous wee chaged fo thei consumption accoding to TaD taiff stuctue ove the yeas so as to bing a positive change on demand side management. Following tables show the compaison of ToD taiff ates along with the base taiff ates fo diffeent time peiods of the day. (2], [3], [4). (5]. [6] '-':1 'i.\ E() 23d National Convention of Electical Enginees / 121
TABLE COMPARSONOF TOO TARFFRATESFORCONTNUOUSNDUSTRES. Ode fo yea Chages fo diffeent time peiods in paisa/kwh fo Continuous industies 22hs- 6hs- 9hs- 12hs- l Shs- 6hs 9hs 12hs 18hs 22hs 2000-01 285 335 365 335 395 2001-02 210 285 335 285 375 203-05 130 215 275 215 315 2006-07 130 215 295 215 325 2007-08 130 310 295 310 325 SOU RCE: VAROUSTARFFORDERSOF MERC TABLEU COMPARSONOFToO TARFFRATESFORNON-CON11NUOUS NDUSTRES Chages fo diffeent time peiods in paisa/kwh fo Non-Continuous industies Ode fo yea 22hs- 6hs- 9hs- 12hs- 18hs- 6hs 9hs 12hs 18hs 22hs 275 325 355 325 385 205 280 330 280 370 203-05 125 210 270 210 310 2000-01 2001-02 2006-07 200 285 365 285 395 2007-08 255 340 420 340 450 SOURCE: VAROUSTARFFORDERSOF MERC Fom above table it is seen that thee is decease in ates fo consumption duing off peak time peiod i.e. 22hs to 06 hs and incease in ates, fo peak powe consumption i.e. fom 18hs to 22 hs. Demand and enegy chages fo continuous and noncontinuous industies fom diffeent taiff odes ae also tabulated below. The table shows that thee is incease in demand chages and decease in enegy chages till the taiff ode 2006-07. n the Taiff ode fo yea 2007-08 the commission has decided and educed fixed and demand chages. t was consideed to be unfai to buden consumes who wee affected by sevee load shedding, and thus MSEDCL now ecoves a geate potion of its demand chages though vaiable enegy chages. Enegy chages as a consequence have been inceased coespondingly. [6] TABLEl COMPARSONOF DE.'-ANDANDENERGYCHARGESFORCONTNUO NDUSTRES. Ode fo yea Continuous industy Demand chages (RslKVA) 2000-01 300 335 2001-02 325 285 2003-OS 350 215 2006-07 350 215 2007-08 300 310 SOURCE: VAROUSTARfFORDERSOFMERC Enegy chages (paisa/kwh) TABLE V COMPARSONOF DEMAND'ANDENERGYCHARGESFORNON-CON11N' NDUSTRES. Ode fo yea Non-Continuous industy Demand chages (RslKVA) Enegy chages (paisa/kwh) 2000-01 280 325 2001-02 300 280 2003-05 330 210 2006-07 350 285 SOURCE: 2007-08 300 340 VAROUSTARFFORDERSOFMERC Due to this vaiation in chages, consumes tend t( thei load fom peak to off peak time which esults eduction in thei electicity bill and load cuve of MS: flattens to cetain extend. V. APPROACHTOWARDSToUTARlFFSTRUCTURE NATONAL LEVEL As mentioned ealie the Ministy of Powe ha: ecognized the impotance of TOU taiff and ecommended the same in National Taiff Policy. This s pesents a bief oveview of applicability of TOU ta diffeent pats of ndia. Electically, ndia is divided it main egions as noth. south, east, west, and noth east Theefoe fo compaison of taiff stuctue in vaious st. ndia, one state fom each zone is andomly selecte analysis is done in tabula fomat. The following states ae selected as a sample fo anal) Nothen egion - Delhi Westen egion - Mahaashta Southen egion - Andha Padesh Easten egion - Oissa Noth easten egion - Aasam TABLE V COMPARSONOFTARFFSTRucuRE FORD\fFE.R.E.TSTATES ie() 23d National Con ven tio of Electical Enginees /122
.- f Nothen egion Delhi. (ajdhani) KVAhbase taiff 50 RslKW month 5.00 Rslunit Westen Southen- Easten' Nonh egion egion egion Easten Maha- Andha- Oissa egion ashtm Padesh state Aasam state taiff based on demand ToD base ToDbase chages pe ToDbase KVA 350 About 100 50-250 40-140 RslKVA RslKVA RslKVA RslKVA month month month month 3.26-3.99 3.75 3.36-3.S0 2.75-3.55 Rs/unit Rslunit RslKWb Rsl KWh SOURCE:VAROUSTARFF ORDERS OF REGULATORY COMMSSON OF RESPEcnVE STATES. n Delhi, taiff fo industies ae KVAh based, while fo Mahaashta, Oissa, and Aasam states taiff fo industial consumes is ToD base. Fo all the states stated above powe facto is to be maintained in between 0.85 to 0.95 as pe thei espective taiff odes. Fo Oissa and Aasam states the penalty chages fo decease in pf ae 1% while in Mahaashta the penalty chage is 2% fo evey 1 % fall in pf below 0.9. n Andha Padesh state thee ae neithe any penalty chages povided fo decease in pf no any incentives given fo any incease in pf and load facto. Powe facto incentive is not applicable fo Delhi and Andha Padesh states. n Mahaashta it is 1% in enegy bill fo pf > 0.95 while in Aasam state it is 2% fo pf > 0.95. Load facto incentive is only povided in state of Mahaashta and fo othe states it is not applicable. [6], [7], (8], (9], [10]. V. CONCLUSON V REFERENCES (1]. K. Paikh. B. S. Reddy. Rangan Banegy. Planning Fo Demand Sid Management in ElecticitySecto. SBN 0.07-46232S-0. e (2] MERC taiff ode fo FY 2000. (Online]. Available' http://www.mec.og.inlodes_2000.him. [3] MERC taiff ode fo FY 2002. [Online). Availahle: hnp:l/www.mec.og.inlodes_2000.him [4] MERC taiff ode fo FY 2004. [Online]. Available: hnp:l/wv;w.mec.og.inlodes_2000.htm [5] MERC taiff ode fo FY 2006. [Online). Available: http://www.mec.og.inlodes_2000.htm (6] MERC taiff ode fo FY 2007. [Online). Available: http://www.mec.og.inlodes_2000.htm [7] 9ERC taiff ode fo FY 2007. [Online). Available: http://decind.oglodespetitionslpetitionslmyt_07 0S. [S] ANERC taiff ode fo FY 2007hnp:llwww.ecap.oglTaiffOdesTO_Siicilla_RESCO 2007. 08.htmL - [9] OERC taiff ode fo FY 2007. [Online). Available: http://www.oiec.oglnewl/odes.htm. [10] AERC taiff ode fo FY 2007. [Online). Available: hup:llaec,nic.inl [11] "Know You Powe" a citizens' pime on the electicity secto, [12] [12] National Electicity Policy. [Online). Availabl: h~tp:"wv:w.powemin.nic.inlindian_electicity_scenaiolnationa3lec~ clty-pohcy.htm [13] Load cuve Data. [Online]. Available: http://mahasldc.iniw. contentlthemeslmahasldcl2oo7/d3 _09102007.htnl P VBL BOGRAPHES Omka Shiisbchanda Pawaska Gaduated in Electical engi~eei~g fom the. Bhaati Vidypeeth College of engmeenng unde univesity of Pune and pesently a post gaduate student of electical engineeing with. powe system as special subject fo~ B~au Vidyapeeth Univesity College of engmeenng, Pune. Two YC?'ls leaching expeience as a lectue in electical engg. 011 gaduation level students. Afte studying oveall philosophy behind the ToD taiff stuctue, it is seen that this -type of taiff stuctue when effectively implemented fo all HT consumes unde MSEDCL has bought the check ove unaffodable geneation costs and made effective utilization of available powe. Also the utility could povide consumes the powe at easonable ates. t is futhe seen that thee is incease in load facto with decease in maximum demand, impovement in powe facto and change in shape of the load cuve due to vaious incentives povided along with ToD taiff stuctue. Thus ToD taiff is found to be an effective DSM tool fo consumes, utility and to society. Ms. Swati Shlish Moe Received the B.E. (Electical) and M. E. (Powe system) degees fom Govenment College of engineeing. Pune. Cuently she is assistant pofesso in depatment electical engineeing. Bhaati Vidyapeeth Univesity Collese of engineeing. Pune. He eseach inteest include powe systems and enegy efficient systems and powe system estuctuing. V. ACKNOWLEDGMENT The authos gatefully acknowledge the help and suppot given by M. Shantanu Dixit, Payas enegy goup, Pune. We also thank to D. D. G. Bhaadwaj, HOD BVUCOE, Pune fo his Suppot. E() 23d National Convention of Electical Enginees /123