Conventional Generation - Thermal Hydro Oil, natural gas and nuclear power accounts for smaller proportion of power. Emphasis also on non-conventional energy sources i.e. solar, wind, biogas and tidal. Captive power plants being encouraged to supply surplus power to Grid.
Diversification Jammu Ludhiana SIKKIM NR Delhi NEPAL BHUTAN Partabpur RAPP Jaipur Guwahati Lucknow CHICKEN NECK NER AR Patna BANGLA MM DESH Vindhyachal ER AN MY Gandhinagar Kolkata Indore Bhopal Korba Pipavav WR Talcher/Ib Valley Raipur Bhubaneswar Tarapur Mumbai Vizag LEGEND Simhadri Hyderabad Generation Load-Centre SR Coal Kaiga Krishnapatnam Ennore Hydro Bangalore South Madras Kozhikode Mangalore Chennai Cuddalore Lignite Coastal Kayamkulam Thiruvananthapuram Kudankulam COLOMBO Nuclear SRI LANKA
Diversification Cost of electricity from different generations, such as hydro, nuclear and thermal differ, depending upon the regional resources and government policies. Energy Resources are unevenly distributed: Coal resources are abundant in Bihar/Jharkhand, Orissa, West Bengal and Hydro Resources are mainly concentrated in Northern and North-Eastern Regions
Electricity Act 2003 has been enacted and came into force from 15.06.2003. The objective is to introduce competition, protect consumers interests and provide power for all.
The Act provides for National Electricity Policy Rural Electrification Open access in transmission Open access in distribution Mandatory SERCs, License free generation and distribution, Power trading, Mandatory metering and stringent penalties for theft of electricity.
Energy traded at Inter State level 35000 30000 30000 25000 22526 23134Energy in MU 20000 16441 15000 10000 5000 0 2004-05 2005-06 2006-07 2007-08 Year
It is the rate at which consumers are required to pay for electrical services Generation, transmission and distribution of the electrical energy involve a huge amount of money Tariff and its governing rules play a very important role in the life, health and growth of the organization.
Low frequency High frequency Very frequent grid disturbances , causing tripping of generating stations, interruption of supply to large block of consumers, and disintegration of the regional grids
1. Capacity Charge: towards reimbursement of the fixed cost of the plant, linked to the plants declared capacity to supply MWs2. Energy Charge: to reimburse the fuel cost for scheduled generation3. Unscheduled Interchange: a payment for deviations from schedule, at a rate dependent on system frequency conditions.
Fixed cost Variable cost Interest on loan Fuel cost, i.e., coal Return on equity and oil in case of Depreciation thermal plants O&M expenses Insurance Nuclear fuel in Taxes and interest case of nuclear on working capital. plants.
The payment of fixed cost to The payment of variable cost the generating company is to the generating company is linked to availability of the dependent on scheduled plant. generation (e.g., if a power plant delivers If average availability over 600 MW while it was the year is higher than the scheduled to supply only 500 specified norm, the MW), generating company gets a the energy charge payment higher payment. would still be for the scheduled generation (500 MW), and the excess generation (100 MW) would This is the first component of get paid for at a rate Availability Tariff, and is dependent on the system termed ‘capacity charge’. conditions prevailing at the time.
UNSCHEDULED INTER-CHANGE (UI) CHARGES The UI for a Generating Station shall be equal to its actual generation minus its scheduled generation. UI for States shall be equal to its total actual drawal minus its total scheduled drawal. UI shall be worked out for each 15 minutes time block. Charges for all UI transactions are based on average frequency of the time block. The UI Tariff structure as on 31.3.2007 is as under. Average Frequency of time-block UI Rate (P/kWh) ---------------------------------------- ----------------------------------- 50.5 Hz and above 0.00 Below 50.50 Hz and upto 50.48 Hz 6.00 Below 49.04 Hz and upto 49.02 Hz 561.00 Below 49.02 Hz 570.00 Between 50.50 Hz and 49.82 Hz Linear in 0.02 Hz steps @ 6 P/kWh for each step Below 49.82 Hz Linear in 0.02 Hz steps @ 9P/kWh for each step 15
PROPOSED NEW UI RATES CERC vide Press Release dated 7-4-2007 has proposed the New UI Vector for enforcing strict Grid discipline as given below : Average Frequency of time-block UI Rate (P/kWh) ---------------------------------------- ----------------------------------- 50.5 Hz and above 0.00 Below 50.50 Hz and upto 50.48 Hz 6.00 Below 49.52 Hz and upto 49.50 Hz 345.00 Below 49.02 Hz 745.00 Between 50.50 Hz and 49.82 Hz Linear in 0.02 Hz steps @ 6 P/kWh for each step Between 49.80 Hz and 49.52 Hz Linear in 0.02 Hz steps @ 9P/kWh for each step Between 49.50 Hz and 49.02 Hz Linear in 0.02 Hz steps @ 16P/kWh for each step COMMENTS ARE INVITED BY CERC BY 23rd APRIL 2007 ON THE ABOVE PROPOSAL FOR REVISION OF UI VECTOR. 17
UI SETTLEMENT MECHANISM IN INTRA-STATE ABTAt Inter – state level the Unscheduled interchanges ofcentral sector and Inter regional sources are determinedwith reference to their schedule at the point of injectionbut those of SEBs with reference to their ex-peripheryschedule. Datum for working out UI not being same forall entities, this results in UI MISMATCH which isequalised by averaging the two ON DAILY BASIS.The above adjustment is required to equalize payable UIamount to receivable UI amount so that UI pool accountis maintained as a Zero balance account. 18
1. UI AMOUNT IS DRAWN FOR ALL THE UI POOL MEMBERS ON ACTUAL BASIS.2. FROM THE UI ACCOUNT AMOUNT RECEIVABLE MEMBERS AND AMOUNT PAYABLE MEMBERS TO THE POOL IS SEPERATELY DRAWN OUT.3. AMOUNT PAYABLE AND RECEIVABLE WILL NOT MATCH BECAUSE FOR GENERATORS THE UI IS DRAWN OUT BASED ON INJECTION & SCHEDULE AT GENERATOR PERIPHERY WHEREAS FOR STATES THE SAME IS BASED ON DRAWAL & SCHEDULE AT STATE PERIPHERY.4. AS PER THE CERC STIPULATION THE UI POOL ACCOUNT SHOULD BE A ZERO BALANCE ACCOUNT.5. AT RPC LEVEL THE UI MISMATCH i.e. THE DIFFERENCE BETWEEN UI PAYABLE & RECEIVABLE IS EQUALIZED BY AVERAGING THE TWO ON DAILY BASIS. HOWEVER THE UI OVER HVDC AND OTHER INTER-REGIONAL LINKS IS RETAINED WITHOUT ANY ADJUSTMENT.6. THE UI MIS-MATCH IS CALCULATED ON DAILY BASIS AND APPORTIONED TO ALL UI POOL MEMBERS IN THE RATIO 50:50 TO THE PAYING AND RECEIVING MEMBERS IN THE RATIO OF THE ORIGINAL UI AMOUNT DRAWN OUT. 19
SCHEDULING GUIDELINES CONSTITUENTS1. While requisitioning power requirement ,minimum technical requirement to ensure the continuity of the generating stations and maximum availability should be taken care of by DISCOMs. The requisition from central sector gas stations should not be less than 70% of the respective availability capacity in normal conditions and 50% under emergency conditions. As far as Hydro and Nuclear stations are concerned, the entire availability would be utilized at all the times. However the storage capacity of Hydro stations is exploited by RLDC depending upon the requirement of the grid.2. Requisition for BTPS should not be less than 80% due to size and age of the machines.3. PPCL cannot go beyond 80% due to pollution stipulations.4. Full requisition should be there for IP and RPH considering their age and core generation.5. Due to size & pollution stipulation for IPGCL’s GT, it should not be less than 70%.
PROCESS FOR SCHEDULINGBY 10:00 HRS— ISGS shall advise NRLDC the station wise MW and MWH capabilities.BY 10:00 HRS— BTPS,GENCO and PPCL shall declare the availability in 15 minutes time block in terms of MW and MWH.BY 11:00 HRS— Entitlement of the state shall be posted by NRLDC in their website www.nrldc.org for central sector.BY 11:00 HRS— SLDC shall post the GENCO,PPCL and BTPS availability in its website www.delhisldc.orgBY 13:00 HRS— NDPL,BRPL,BYPL,NDMC and MES shall intimate the SLDC, source-wise requirement of power for succeeding day in terms in MW and MWH in 15 minutes time block.BY 15:00 HRS— SLDC shall assess the requirement of power from all sources and intimate the same to NRLDC.BY 17:00 HRS— NRLDC shall convey the net drawal schedule for Delhi and posted in the website.BY 18:00 HRS— SLDC shall post the provisional Drawal Schedule and Generation Schedule of Generating stations within Delhi based on the provisional Drawal schedule of Delhi as a whole posted on the NRLDC website.BY 19:00 HRS— GENCOs/Licensees shall alter the schedule of generation /requirement and intimate the same to SLDC for forwarding the same to NRLDC for incorporation in final drawal schedule of Delhi.BY 22:00 HRS— SLDC shall inform the modification if any,for incorporating in the final drawal schedule to NRLDC.BY 23:00 HRS— NRLDC shall issue the final drawal schedule of Delhi state along with other states and posted in their website.BY 23:30 HRS— SLDC shall compute the drawal schedule of DISCOMs and generation schedule of generating stations within Delhi based upon the availability from central sector stations bilateral agreements entered into by various distribution licensees for the next day. Intra-day scheduling as per IEGC provisions is also permitted.
Enhanced grid discipline ensuring quality power supply for all consumers. Improvement in grid voltage levels leading to reduction in transmission losses and enhancement of transmission capacity. Enabling environment for meeting peak demand. Promote power trading & commercial dealings. Introduce and encourage merit order dispatch in Indian power system.
Benefits of Intra – State ABTa) Benefits to the Power System• Brings about grid discipline by maintaining frequency in prescribed band (49.5 to 50.5 Hz).• Ensures optimum utilization of available generation capacities.• Enhances opportunities for Open access, and Trading of electricity.• Scope for encouraging competition among generators.
b) Benefits to the Generator • Encourages maximization of Generation during peak hours with incentives and discourages the same during off-peak hours with penalties linked with frequency. • Enables systematic scheduling in terms of long term, short term as well as day ahead, duly considering plant availability and maintenance. • Ensures better life of equipments due to efficient management of Demand Vs Supply. Thereby the ‘Hidden Costs’ due to damage is avoided. • The three-part Tariff under ABT provides for proper recovery of fixed and variable costs of Generator.
c) Benefits to the Distribution Licensees • Economic efficiency dictates that the least cost power should be dispatched in preference to costly power (Merit Order Dispatch). ABT provides for the same. • Licensees can plan their requirement, both for peak and off peak demands. • Enables efficient Load Management through their own Area Load Dispatch Centers.
d) Benefits to the End Users• Enables open access, captive generation and trading of electricity.• Ensures quality and reliable power supply.• Scope for reduction in cost of power due to licensees opting for merit order dispatch in their scheduling.
The ABT must be extended to state and retail level up to the level of feasibility. Time-differentiated tariff can further encourage the stack holders to participate in the system management. The real time pricing may have locational features in addition to the system condition. Subsidy should be reduced in phased manner and finally be eliminated within the target period.
Cross-subsidization should not be done from other type of the consumers within the system; rather it should be done from the other areas in consultation with the ministry that deals the matters of social welfare. More encouragement should be given to private investors. Open market to be developed for better power trading.
Tariff amendments after the Electricity Act 03 have played a major role to bring discipline and responsibility in the Indian Power System. The UI mechanism provides equal chance of earning the performance-linked incentive to generators as well as loads. With increased complexity of the power system, tariff has became very complex and involved concept to realize. A novel competitive power market in India is yet to evolve.