3 rd Technical Workshop: Gas Market Design and Natural Gas Transmission Grid Codes

Transcription

1 3 rd Technical Workshop: Gas Market Design and Natural Gas Transmission Grid Codes Contextualizing Transmission Grid Codes in the Natural Gas System - The Intersection of Transmission and Distribution Grid Codes Fotis Thomaidis Partner, VIS Economic & Energy Consultants 22/05/2018

2 AGENDA Overview of distribution grid codes development Allocation of volumes at transmission entries and exits Alternatives for allocation at exits to distribution and transitional path for developing an allocation methodology 2

3 Overview of distribution codes Allocation of volumes at transmission entries & exits Allocation of volumes at exit points to distribution 3

4 Intersection of grid code with other operation rules Distribution network code(s) Other system codes (LNG, UGS) Interconnection Agreements Transmission grid code Supply code Licencing rules Emergency plans 4

5 Overview of distribution network code The distribution code is a document that defines: The rights and responsibilities of the DSO, the users of the distribution network, and the final consumers, as regards to their connection to the network The interactions between the DSO and user, consumers and the TSO The distribution code is usually approved by the Regulator, following proposal of the DSO(s), and public consultation The EC Network Codes requirements related to the distribution codes are limited only to the provision of information to the TSO for allocation purposes Interactions between the transmission and distribution code focus mainly on the nomination and allocation of volumes 5

6 Development of distribution codes in the EU Unlike transmission grid codes, the structuring of distribution codes differs across the EU, and depends on the requirements of the national legislation In some countries the distribution code constitutes a single and comprehensive document, whereas in others it is a collection of different regulations, model contracts and processes In some cases a model distribution code is used by all DSOs of a country, whereas in others each DSO has its own code Regardless of the above, all distribution codes include the main provisions determining the rights and obligations of all parties involved in distribution, and the coordination requirements between the DSO and TSO 6 6

7 Examples of different codes of EU DSOs Single document with references in several inter-linked regulations Reg. for communication in the gas sector Reg. for communication standard Network Code Provisions included in model contracts with users / final consumers and separate documents describing specific procedures Contract with system user Pool of Procedures Indicative Contract with final consumers Procedure for connection of new household to the system The code provisions are included in several legislative documents Cooperation Agreement between operators of German gas supply networks (TSOs & DSOs) Energy Industry Act (EnWG) Basic Gas Supply Regulation (GasGVV) Ordinance on Network Charges (GasNEV) Reg. for free access to distribution services Reg. for distribution tariff reform Reg. for quality and pricing of distribution services Reg. for criteria of distribution tariff Procedure for customer complaints Procedure for cancelling appointments of technicians with final consumers Ordinance on Network Access (GasNZV) Metering Access Ordinance (MessZV) Ordinance on Incentive Regulation (ARegV) 7

8 Usual contents of transmission and distribution codes Services offered by the TSO Services offered by the DSO Access to the system (firm, interruptible) Access to the system (firm) Transmission Code Congestion management New connections Gas delivery & withdrawal, gas quality Nomination / renomination Allocation of volumes Balancing Metering Connections / disconnections / reconnections Gas delivery & withdrawal, gas quality Nomination Allocation of volumes Metering Distribution Code Exchange of information Exchange of information System development & maintenance System development & maintenance Handling of emergencies Handling of emergencies 8

9 Overview of distribution codes Allocation of volumes at transmission entries & exits Allocation of volumes at exit points to distribution 9

10 What is allocation at a transmission entry or exit point Nomination of shipper 1 + Nomination of shipper 2 + Nomination of shipper 2 Confirmation by TSO Confirmed quantity of shipper 1 + Confirmed quantity of shipper 2 + Confirmed quantity of shipper 3 Aggregate confirmed quantity at point Meter reading at the point Allocation of volumes to shippers at entry / exit point 10

11 Allocation methodology at transmission points The methodology applied by the TSO to allocate volumes to shippers at entry and exit points of transmission may differ: Interconnection points: The allocation rule foreseen in the interconnection agreement with other TSOs (operational balancing account is the default) Exits to distribution: The allocation process depends on the exchange of information between TSO and DSOs, especially for non-daily metered customers Exit points to consumers: Measurements are allocated to the shipper(s) supplying the consumer Other entry/exit points: Allocation on the basis of agreements with connected operators To ensure coordination between TSO and DSOs, rules have to be introduced within the transmission and distribution codes, or in a separate agreement between the operators 11

12 Revisions of allocated volumes A first allocation of volumes is provided to shippers as soon as possible (initial allocation) The allocation is revised at least once using updated / validated data (final allocation) Day D+1 Optional step Timing depends on legislation Initial allocation Revised allocation Final allocation Initial measurements Initial estimates Validated measurements Updated estimates Validated measurements Updated estimates Feedback from shippers 12

13 Overview of distribution codes Allocation of volumes at transmission entries & exits Allocation of volumes at exit points to distribution 13

14 Allocation of quantities at exit points to distribution Transmission Exit Point Distribution Not all final consumption daily measured Allocation requires estimates City Gate Distr. Network User(s) NDM Shippers DM Final consumption daily measured Allocation uses measurements DM Bottom-up allocation based on customer portfolio of each shipper 14

15 Transitional path of allocation methodology at exit points Pro rata Increasing interaction between TSO - DSO Allocation based on pro-rata allocations at distribution level (ex-post next month) Requirement of EC Network Code on Balancing Allocation based on forecasts at distribution level (ex-post next month) Allocation based on forecasts at distribution level (day-ahead / within day / next day) 15

16 Pro-rata rule overview Includes proportional allocation of measured volumes at the exits to distribution on the basis of the daily confirmed quantities submitted by each transmission user It is the simplest approach, and does not require interaction with DSOs Its main drawback is that it may not capture large imbalances caused by a single distribution user, as the allocation at distribution points is based only on declared volumes and not on actual consumption 16

17 Pro-rata rule example Distribution S1 Exit Point Confirmed Quantity: 50,000 MWh Measurement: 130,000 MWh DU1 DM Consumed (Measured): 80,000 MWh S2 DU2 Consumed: 50,000 MWh Confirmed Quantity: 50,000 MWh NDM Allocation: -> S1: 65,000 MWh (50%) -> S2: 65,000 MWh (50%) Actual Consumption: -> S1: 80,000 MWh (62%) -> S2: 50,000 MWh (38%) 17

18 Monthly pro-rata allocation at distribution (1/2) At the exit points to distribution, the allocation to shippers is carried out taking into consideration measurements for daily metered and prorata allocation for non-daily metered consumers at distribution level The TSO performs the day-ahead initial allocation pro-rata, and revises the allocation at the end of the month with information from the DSO This option requires monthly interaction between TSO and DSOs The allocation may be performed either by the TSO or by the DSO, using information collected by the DSO and matching distribution users with the shippers that delivered gas to them 18

19 Monthly pro-rata allocation at distribution (2/2) Distribution consumers Allocated volumes Allocation approach Daily measurements Actual consumption City Gate DM NDM Volumes not consumed by daily-metered consumers Difference between measurements at city gates and daily-metered consumers Pro-rata using confirmed quantities Allocation to distribution users Matching shippers with supplied distribution users Allocation to shippers 19

20 Monthly allocation at distribution with forecasts (1/2) At the exit points to distribution, the allocation to shippers is carried out taking into consideration measurements for daily metered and forecasts for non-daily metered consumers at distribution level Forecasts are based on consumption profiles for different types of consumers, carried out by the DSO, TSO or a 3rd party (forecasting party) The TSO performs the day-ahead initial allocation pro-rata, and revises the allocation at the end of the month with information from the DSO This option requires monthly interaction between TSO and DSOs The allocation may be performed either by the TSO or by the DSO, using information collected by the DSO and matching distribution users with the shippers that delivered gas to them 20

21 Monthly allocation at distribution with forecasts (2/2) Distribution consumers Allocated volumes Allocation approach Daily measurements Actual consumption City Gate DM NDM Forecasts for relevant consumer category Forecasted consumption Allocation to distribution users Matching shippers with supplied distribution users Allocation to shippers 21

22 Monthly revisions of allocated volumes D+1 M+1 Transmission Initial allocation Pro Rata Allocation Revised allocation Pro Rata Allocation (verified measurements) Final allocation Allocation updated with distribution allocation Distribution Initial allocation for distribution Allocation based on bottom-up estimation (pro-rata or forecast) 22

23 Example of allocation schedule (1/2) D, M D+1, M Day D, Month M, Gas Flow Day D+1, Month M, Indicative Allocation of Natural Gas Quantities (Pro rata) D+3, M+1 D+5, M+1 D+5, M+1 D+7, M+1 Day D+3, Month M+1, System Users submit to TSO the Distribution Users to which they supplied gas Day D+5, TSO sends to DSOs daily measured quantity per city gate, Transmission Users active at each city gate and Distribution Users to which they supplied gas Day D+5, Month M+1, Initial Daily Allocation of Natural Gas Quantities, with validation of measurements (Pro rata) Day D+7, Justified objections to the Initial Allocation may be submitted by the Transmission Users 23

24 Example of allocation schedule (2/2) D+9, M+1 D+9, M+1 D+10, M+1 Day D+9, Transmission Users may communicate to the Operator their established agreement for an Allocation different from the Initial Allocation Day D+9, DSOs send to the TSO the daily quantity allocated to each Transmission User that was active in city gates of the distribution system Day D+10, Final Daily Allocation of Natural Gas Quantities, with validation of measurements, feedback from Transmission Users and allocated quantities provided by the DSOs (DSO Input) 24

25 Requirements of EC Network Code on Balancing The DSO and the forecasting party must provide data to the TSO on a daily basis, that will be used for the initial allocation and the daily information of shippers The DSO must also provide up-to-date information to the forecasting party, to be used for developing the forecasting methodology as well as for performing the forecasts The data to be provided depends on the information model applied by the TSO, such as: Measurements for daily metered customers for previous day or same day Links between shippers and distribution users Reconciliated measurements for non-daily metered consumers 25

26 Base Case - Information flow to a shipper on Gas Day D-1 Forecasting Party City gate NDM Forecast for demand for Day D Measured offtakes for Day D-2* For each shipper TSO Forecasting for shipper NDM forecasts no later than 12:00 UTC Shipper (Information useful for nominations) DM DSO * Not an information requirement by the EU NC, but applied in practice 26

27 Base Case - Information flow to a shipper on Gas Day D Forecasting Party City gate NDM DM Updated Forecast for demand in Day D Twice within Day D Measured offtakes for Day D-1* DSO For each shipper TSO Updated forecasting for shipper Twice within Day D: 1 st update no later than 13:00 UTC 2 nd update time defined by Regulator Shipper (Information useful for renominations) * Not an information requirement by the EU NC, but applied in practice 27

28 Base Case Initial allocation to a shipper on Gas Day D+1 City gate Forecasting Party NDM NDM Updated Forecast for demand in Day D Reconciliation (Measurement vs allocated quantities for NDM customer) For each shipper TSO Measured offtakes for Day D Initial allocation for shipper* Shipper Measured offtakes for Day D DM DSO DM * A Final Allocation will be performed with updated information later (usually one month after the initial allocation) 28

29 Overview of allocation mechanisms Interaction TSO-DSO Sufficiency Requirements Use Pro rata None Low Nominations at transmission Daily Allocation Monthly pro-rata allocations at distribution level Monthly Medium Nominations at distribution Monthly Allocation Monthly allocation based on forecasts at distribution level Monthly High Accurate consumption profiles Monthly Allocation Daily allocation based on forecasts at distribution level Daily High Accurate consumption profiles Daily Allocation & Balancing 29