Availability-based tariff

General layout of electricity networks (typical).

Availability Based Tariff (ABT) is a frequency based pricing mechanism applicable in India for unscheduled electric power transactions. The ABT falls under electricity market mechanisms to charge and regulate power to achieve short term and long term network stability as well as incentives and dis-incentives to grid participants against deviations in committed supplies as the case may be.[1]

Introduction

ABT Mechanism in Electricity sector in India is adopted since the year 2000 and in a few other countries for pricing bulk power across various stakeholders. ABT concerns itself with the tariff structure for bulk power and is aimed at bringing about more responsibility and accountability in power generation and consumption through a scheme of incentives and disincentives. As per the notification, ABT was initially made applicable to only central generating stations having more than one SEB/State/Union Territory as its beneficiary. Through this scheme, the Central Electricity Regulatory Commission (CERC) looks forward to improve the quality of power and curtail the following disruptive trends in power sector:

The ABT scheme has now been expanded to cover the Intrastate systems as well.[2] The power generation or grid capacity has increased substantially in last fifteen years particularly after the Electricity Act 2003 by introduction of competition and unbundling of vertically integrated utilities (SEBs) into separate entities in charge of electricity generation, electricity transmission, and electricity distribution. Deregulation and competition has facilitated participation of private sector on large scale in electricity generation, transmission and distribution. Of late, Indian electricity sector is transforming from perennial deficit to surplus electricity availability.[3] The volume of purchased electricity that could not be transmitted to the buyers due to transmission lines congestion is only 0.3% of the total electricity consumed in the financial year 2013-14.[4] It means that the actual power deficit in India is less than 1% excluding under priced electricity demand. ABT/DSM mechanism needs improvements to address the requirements of all stake holders (including final electricity consumers) for encouraging least cost electricity generation / tariff based on demand verses availability in the grid.[5][6] There is a need of well represented Electric Reliability Organization to involve all the grid participants for framing guidelines for power system operation and accreditation which is presently looked after by the CEA

Bulk power purchasers can buy electricity on daily basis for short, medium and long term duration from reverse e-auction facility.[7] In reverse e-auction, availability based tariff is applied to settle the failed commitments by the electricity sellers or buyers[8][9] The electricity prices transacted under reverse e-auction facility are far less than the prices agreed under bilateral agreements.[10][11]

ABT details

Availability, for the purpose of the ABT order means the readiness of the generating station to deliver ex-bus output expressed as a percentage of its ex-bus rated capacity (MCR). Electricity is a commodity whose cost of storing is more than its production cost. The most economical method for electricity generation, transmission and distribution is just in time production where the availability and reliability of the entire system shall be very high to meet the unpredictable electricity demand on minute to minute basis.

Availability of thermal generating station for any period shall be the percentage ratio of average Sent Out Capability (SOC) for all the time blocks during that period and the rated MCR / SOC of generating station. The SAIDI (System Average Interruption Duration Index) is commonly used as a reliability indicator by electric power utilities.

During the fiscal year 2014-15, 1,043 billion KWh of electricity (three times that of National Grid) was supplied and met 138,215 MW maximum peak load.[12] The total installed generation capacity is 267,637 MW at the end of fiscal year 2014–15. Its size is of global scale comparable only with EU grid, NERC grid, China electricity grid and Russian electricity grid.[13] However, Indian grid lacks the basic features of smart grid for optimum use of its deployed resources.[14]

Generally the top 10% of the unrestricted daily peak load (MW) persists only for 1% (15 minutes) of the total duration and its energy share (MWHr) is of the order of 0.2% of the daily energy supplied. Instead of generating this substantial extra power for a short duration, automatic selective load shedding can be implemented on bulk consumers with standby power facility to eliminate the load spikes without inconvenience to most of the consumers.[15][16] Alternatively, working captive power plants start feeding to the grid by giving break to the captive power supply up to a maximum of 30 minutes duration. The standby generator / captive power owner would be paid for providing grid reserve ancillary services.

With an installed capacity of proper mix of base load and variable load generation capability (excluding low capacity utilisation or secondary power or negative load type on daily basis such as solar, wind, etc) equivalent to the unrestricted annual maximum peak load, the most effective and economical smart grid shall be able to cater more than 99 percentile duration unrestricted load/demand on daily basis with 100% stable operation of the grid.[17][18] The purpose of smart grid is to supply required electricity at optimum cost with reliable supply to the final consumers.

Scheduling

ABT features

Consumer category-wise electricity tariff

ABT drawbacks

An idealized representation of the four kinds of reserve power and the time intervals after an unexpected failure that they are in use.[19]

Natural gas transmission

The Petroleum and Natural Gas Regulatory Board (PNGRB) was created in the year 2005 to regulate downstream activities in the petroleum and natural gas sector.[35] There is requirement of natural gas TSO also for imparting optimum use of the gas on hourly basis for meeting peak load in the electricity grid and minimize gas transport distances. The available gas should be stored up to rated pressure in the pipe grid for generating power during peak demand hours on a daily (or more) basis. Thus available limited quantity is needed to meet the peak electricity loads by all gas based power stations. Also gas should not be transported from a power deficit region to a power surplus region by the gas grid and generated power from gas there shall not be transmitted to the power deficit region to avoid misuse of the gas and power grid infrastructure. Natural gas TSO would also serve other sectors such as petro-chemical plants, CNG, Fertilizer plants, PNG, LNG, etc. as per their hourly requirement in addition to receive gas from various types of natural gas producers.

See also

References

  1. "ABC of ABT" (PDF). Archived from the original (PDF) on 12 March 2014. Retrieved 14 August 2014.
  2. "MERC Order on ABT in State of Maharashtra". Retrieved 14 August 2014.
  3. "Open Access in Indian power sector" (PDF). Retrieved 15 May 2013.
  4. "Tables 1 & 25; Report on Short-term Power Market in India, 2014-15" (PDF). Retrieved 4 October 2015.
  5. 1 2 3 4 Electricity online trading in India
  6. "Integrating European Electricity Markets" (PDF). Retrieved 15 May 2013.
  7. "Government asks states to purchase short term power through reverse e-auction". Retrieved 5 April 2016.
  8. "Vidyut Pravah". Retrieved 3 July 2016.
  9. "IEX Power Trading Process Flow". Retrieved 3 July 2016.
  10. "Reverse e-auction lowering power prices. Ind-Ra". Retrieved 26 May 2016.
  11. "Area prices in reverse e-auction trading". Retrieved 26 September 2016.
  12. "April, 2015 Monthly report, National Load despatch Centre (NLDC)" (PDF). Archived from the original (PDF) on 27 May 2015. Retrieved 25 May 2015.
  13. Electricity sector in India#Electricity transmission and distribution
  14. "India can achieve 1,650 billion units of electricity next year, Piyush Goyal". Retrieved 9 July 2016.
  15. Control of the National Grid (Great Britain)#Frequency Service
  16. "How Smart Is The Smart Grid?". Retrieved 17 August 2014.
  17. Talk:Availability-based tariff
  18. "National Study by NREL-Pathways to Integrate 175 Gigawatts of Renewable Energy into India's Electric Grid, Vol I" (PDF). Retrieved 7 July 2017.
  19. B. J. Kirby, Spinning Reserve from Responsive Loads, Oak Ridge National Laboratory, March 2003.
  20. "Real Time Power Grid Frequency". Retrieved 6 August 2015.
  21. 1 2 "Deviation Settlement Mechanism and related matters, CERC, GoI" (PDF). Retrieved 6 August 2015.
  22. "Typical daily frequency graph of Indian grid" (PDF). Archived from the original (PDF) on 4 March 2016. Retrieved 6 August 2015.
  23. "ENTSO-E Operation Handbook Policy 1 (2009), Load frequency control & performance,(refer last page)" (PDF). Retrieved 6 January 2015.
  24. "Ease trading of power". Retrieved 27 April 2015.
  25. "Power Minister Piyush Goyal says power available for free". Retrieved 1 May 2015.
  26. "CERC regulation on Ancillary Services Operations, 2015". Retrieved 26 August 2015.
  27. "Daily reports; Power supply position; SRLDC". Archived from the original on 17 July 2014. Retrieved 17 August 2014.
  28. "Monthly generation report of power stations; October, 2015; CEA". Retrieved 13 November 2015.
  29. "Gensets add up to under half of installed power capacity; August, 2014". Retrieved 13 May 2015.
  30. Commercial Opportunities for Back-Up Generation and Load Reduction via National Grid, the National Electricity Transmission System Operator (NETSO) for England, Scotland, Wales and Offshore.
  31. "How to Turn Standby Generation Into Profit-Making Assets". Retrieved 13 March 2015.
  32. "Modification to existing transmission lines to double the capacity". Retrieved 9 June 2015.
  33. "Reserve Regulation Ancillary Services (RRAS) Implementation in Indian Grid". Retrieved 9 January 2017.
  34. "Ancillary Services – Monthly Reports -2016-17". Retrieved 9 January 2017.
  35. "The Petroleum and Natural Gas Regulatory Board Bill, 2005" (PDF). Retrieved 17 August 2014.
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