Background to national grid s baseline analysis
This presentation is the property of its rightful owner.
Sponsored Links
1 / 18

Background to National Grid’s Baseline analysis PowerPoint PPT Presentation


  • 40 Views
  • Uploaded on
  • Presentation posted in: General

Background to National Grid’s Baseline analysis. 14 August 2007. Agenda. Baselines during TPCR 2002 - 2007 Consultation during the TPCR 2007 – 2012 Ofgem’s modelling requests National Grid’s Network Analysis Ofgem’s Updated and Final Proposals. Baselines during TPCR 2002 - 2007.

Download Presentation

Background to National Grid’s Baseline analysis

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Background to national grid s baseline analysis

Background to National Grid’s Baseline analysis

14 August 2007


Agenda

Agenda

  • Baselines during TPCR 2002 - 2007

  • Consultation during the TPCR 2007 – 2012

  • Ofgem’s modelling requests

  • National Grid’s Network Analysis

  • Ofgem’s Updated and Final Proposals


Baselines during tpcr 2002 2007

Baselines during TPCR 2002 - 2007

  • How were the baselines set?

  • Baselines set on ‘Maximum Physical Entry Capacity’ (MPEC) methodology

    • Theoretical maximum through each ASEP

    • Ignored interactions between ASEPs

  • Obligations (SO baselines) set at 90% of MPEC

  • Baselines in aggregate (9755 GWh/d) acknowledged to be in excess of Physical capability of the system

  • Essentially purely a nodal model (no substitution)


Consultation during tpcr 2007 2012

Consultation during TPCR 2007 – 2012

  • Problems with current arrangements?

    • High baselines coupled with zero priced capacity on the day discouraged Long-Term Signals and encouraged Short-Term bookings

    • Problems for new entrants (ASEPs) – not able to secure capacity which was not yet booked at existing entry points

  • View that current arrangements were not flexible enough to deal with changing demands for capacity

  • Debate over retention of entry specific baselines or move to more aggregated level?

  • Should modelling be based on supply substitution or load absorption?

  • Discussion whether baselines should exceed physical capability of the system (at peak)


Load absorption vs supply substitution

Load Absorption vs Supply Substitution

  • Purpose of the modelling was to determine the maximum supply capability at different points on the system

  • Starting point for any network analysis is that supply equals demand

  • How do you increase supply, yet keep supply and demand in balance?

  • Load Absorption:

    • As supplies are increased at entry points, demands are increased pro-rata to keep supply and demand in balance

  • Supply Substitution:

    • As supplies are increased at entry points a corresponding other supply point is reduced (demands kept fixed)


Ofgem s initial modelling request

Ofgem’s initial modelling request

  • Network:

    • Initially for 2 years 2007/8 and 2008/9

  • Demand side: central case forecast 1 in 20.

  • Supply side:

    • Initially just TBE Auctions + scenario for 2007/08 for all entry points and for 2008/09 for MH and IoG Initially, employ both supply substitution and 50/50 supply substitution/load absorption

      • Using least favourable node as supply balance

  • Modelling work produced four sets of data on “baseflows” (which reflected the initial supply scenario)

  • Also produced “free increments” (reflecting network capability at individual nodes or zones)

  • Modelling involved around 4 x 26 sets of analysis (104 man days effort)


Ofgem s further modelling request

Ofgem’s further modelling request

  • Network:

    • Settled on using only 2008/9

  • Demand side: central case forecast 1 in 20.

  • Supply side:

    • Settled on using three TBE scenarios (Auctions +, Transit UK and Global LNG) using supply substitution

      • Using least favourable node as supply balance

  • Modelling work produced three sets of data on “baseflows” (which reflected the initial supply scenario)

  • Also produced “free increments” (reflecting network capability at individual nodes or zones)

  • Modelling involved 3 x 21 sets of analysis (58 man days effort)


Ofgem s initial proposals

Ofgem’s Initial Proposals

  • Ofgem’s Initial Proposals (June 2006):

    • Decided on entry point baselines

    • Baselines should be set consistent with physical capability of the network (to include planned investments)

    • NGG NTS to introduce methodology for substituting baselines (in response to auction signals)

    • Modelling work favoured supply substitution

    • Proposed baselines were set on average of 3 TBE scenarios of ‘baseflow’ + 90% of ‘free-increments’

  • NGG NTS re-iterated that baselines should not exceed physical capability of the system and in their view, Ofgem’s IPs did exactly that

    • Within response to IP document, NGG NTS outlined its views for modelling network capability and baselines


National grid s network analysis

National Grid’s Network Analysis

  • Based on

    • 2006 plan ( i.e. on 2005 TBE data)

      • Central Supply scenario

      • 2008 Network

      • Hence included planned investments such as those on East Coast, Trans-Pennine pipeline

    • Zonal analysis (High case/Low case capabilities)

    • Taking strong account of network interactions on the system; and

    • Capacity commitments already sold


Nts entry zones

NTS Entry Zones


Zonal best worst case peak day 2008 mscm d

Zonal Best/Worst Case - Peak day 2008 (mscm/d)


Zonal high low capabilities

Zonal High/Low Capabilities


Principles of allocation

Principles of allocation

  • No reduction in existing entry capacity commitments allowed

    • Based on maximum daily quantity booked for winter of 2007; plus

    • Incremental capacity released at each entry point from 2007

  • Any remaining capacity allocated on pro rata basis in proportion to expected peak level of supply

  • Highlighted interactions between zonal capabilities

    • If optimise Northern Triangle first, this results in reducing East Coast and West Coast zones below capacity rights already sold

    • East Coast zone chosen as starting point, hence based on ‘high’ case capability of 4127 GWh/d

      • Combined with Milford Haven at obligated level (950 GWh/d)

      • Results in only 1895 GWh/d of capability in Northern Triangle


Zonal proposed baselines

Zonal Proposed Baselines


National grid s initial proposals for baselines

National Grid’s initial proposals for baselines


Ofgem s updated proposals

Ofgem’s Updated Proposals

  • Ofgem’s Updated Proposals (September 2006):

    • Stated that “baselines should be set at levels consistent with the simultaneous physical accommodation of possible flows under a wide range (although not all possible) scenarios across entry points”

    • Clarified that baselines will be set such that no baseline is less than the amount of obligated capacity already sold

    • Proposed reduction of proportion held back for shorter-term auctions to 10%

  • NGG NTS outlined concerns that not yet seen baselines which meet Ofgem’s stated aims


National grid s proposals for all aseps

National Grid’s Proposals for all ASEPs


Ofgem s final proposals

Ofgem’s Final Proposals

  • Ofgem’s Final Proposals (December 2006):

    • Stated that believed baselines reflected physical capability of the network

    • Baselines were consistent with the allowances made for NGG NTS in respect of the costs of buying back capacity

  • National Grid believed FP baselines still carried risk as above its proposed baselines

Note that no zonal analysis performed for NW or SW zones


  • Login