16-08-2012, 04:11 PM
Availability Based Tariff
Availability Based Tariff.ppt (Size: 105 KB / Downloads: 52)
Objectives
To stabilize frequency in the regional grids and to minimize extreme deviations in the frequency so as to provide quality and reliable power to the consumer.
Facilitating merit order dispatch thereby promoting economy and efficiency and healthy competition in the power market.
Incentives for improvement in performance and disincentive for deviations.
To co-relate Central Generating Station, State owned Generating Stations and IPPs.
Optimum utilization of available total power in the nation by using National Grid.
To formulate clarity in Tariff Structure to eliminate unethical power trading in the country.
To promote accountability of power availability in the distribution system.
To promote quality of power in India comparable with International Level.
Availability Based Tariff
With a view to promote overall economic operation of the power sector and to achieve improvement in operational parameter, a three part tariff structure was introduced.
Fixed / Capacity Charges for the Generator
Energy Charges and
Charges for Deviation which is frequency-linked.
Fixed / Capacity Charges
Capacity charge is based on Annual Fixed Charge
Ex-bus output of generating station for the day declared before the day starts multiplied by the percentage share of the constituent SEBs.
The norms decided for recovery of fixed charges is based on 80% availability of the generating station.
If Availability Factor exceeds 80%, incentives at the prevailing rate are also envisaged. In case the generating station operates below 80% availability, the fixed charges reduce proportionately.
Charges for Deviation i.e Unscheduled Interchanges (UI):
Charges for deviation, GS has to abide by the declaration of availability on each day for a particular time interval of 15 minutes. If this deviation occurs on the negative side during low frequency, GS will be penalized and if the deviations are based on the high frequency side, then GS will not be entitled for payment.
In case of utility, if the drawl is less than the schedule given, the utility has to pay full charges as per schedule.
Drawal at low frequency, penalty for this excess drawal levied to utility.
High frequency, utility draws less than schedule, the energy charges based on the schedule given. In case of over drawal of energy over and above the schedule, the deviation will be at no charge.
Variations in actual generation/drawal and scheduled generation/drawal are accounted through UI as per formula stated below
UI = (Actual energy interchange in a 15 minute time block - scheduled energy interchange for the time block ) UI rate for the time block.
Total payment for the day
= (Capacity charge + Energy charge + UI charge)
Advantages of ABT
Facilitates grid discipline
Facilitates trading in capacity and energy
Facilitates merit order dispatch as and when made effective
Improved frequency and voltage
Economic dispatch
Autonomy to the utility
Incentive for high plant availability, but no incentive to over generation during off-peak hours
Technically and commercially right
Immediate solution for IPPs and Captives
True free market : market forces decide the pool price
Pool price known on-line
Total transparency
Simple practicable as special energy Meters are developed and installed