The indicators below are calculated from simulation outputs. Output values being unrounded, the indicators were calculated with decimals and rounded for the presentation of results. It can happen that they differ from indicators which would be calculated from published rounded prices and flows.
a. Welfare Indicators Let us denote:
• CW the coupling welfare which is optimized by the coupling algorithm (which includes some losses costs modeled via the linear loss factor);
• LC the total external losses cost (including additional energy production) which is not considered in the implicit allocation calculated by the algorithm43;
• NCW the net coupling welfare;
Theoretically, the net coupling welfare encompasses the surplus of every party, including the producer surplus of the producer who procures energy for losses when losses are procured out of the coupling mechanism.
In practice, we consider a calculated net coupling welfare NCWc which is defined as follows: NCWc = CW – LC; we still call this quantity net coupling welfare and we generally omit the ‘c’ though this is not strictly correct.
The coupling welfare is the sum of producer and consumer surplus and gross congestion rents over all bidding areas and interconnections:
CW = Σ PS + Σ CS + Σ CR.
Producer and consumer surplus represent the gain compared to the willingness to pay and are directly output by the coupling algorithm.
Gross congestion rent is calculated for each interconnection as the difference between the amounts for energy sales at one end and energy purchase at the other end of the interconnection:
CR = MCPImporting.FlowReceivingEnd – MCPExporting.FlowSendingEnd.
For each interconnector and each run#n, the hourly loss costs are calculated as follows:
LC = (loss factor run#3 – loss factor run#n)/(1 – loss factor run#3).MCPExporting*FlowSendingEnd
Case of adverse flows (due to ramping or negative ATCs): losses should be procured at the importing side (cheapest price) leading to the following formula:
LC = (loss factor run#3 – loss factor run#n).MCPImporting*FlowSendingEnd
43 Theoretically, LC = DC LC + AC LC is the sum of losses supported by DC cables and losses supported by the AC part of the network; AC LC is assumed to be constant and is not considered further in the comparison analysis of different runs.
98 Example:
• If run #3 has a loss factor of 3%, if run #1 results in a flow of 100MW, then 3MW losses must be compensated;
• If run #3 has a loss factor of 3%, if run #2 has a loss factor of 2% and results in a flow of 100MW, then 1MW extra-losses must be compensated;
The calculation of loss cost as above relies on the following assumptions:
• The linear loss factor for run #3 exactly reflects the losses to be taken into account for the assessment of the loss costs i.e. every loss cost is included in the linear loss factor used in run #3 whatever the flow; in particular, the assessment of LC will not use the parabolic formulae as functions of actual physical flows;
• The cable operator buys the lost energy at the Market Clearing Price in the cheapest side (see Annex 4 for a rationale for this price);
• The modality of losses procurement by cable operators has no impact on the formation of market prices, whatever the term (forecast and order on the market; or procurement on intra-day / balancing);
b. Flow Indicators
Each interconnector has two directions arbitrarily denoted up and down; a flow in a given direction can be seen at the sending end (injection point; denoted ”in”) and at the receiving end (off-take point; denoted
”out”). The following indicators are calculated (for each interconnector and each run):
UPINNCG: sum of sending end flows in up direction over hours when no congestion occurs UPOUTNCG: sum of receiving end flows in up direction over hours when no congestion occurs DOWNINNCG: sum of sending end flows in down direction over hours when no congestion occurs DOWNOUTNCG: sum of receiving end flows in down direction over hours when no congestion occurs UPINCG: sum of sending end flows in up direction over hours when congestion occurs
UPOUTCG: sum of receiving end flows in up direction over hours when congestion occurs DOWNINCG: sum of sending end flows in down direction over hours when congestion occurs DOWNOUTCG: sum of receiving end flows in down direction over hours when congestion occurs NBHCGUP: number of hours when the interconnector is congested in the up direction
NBHCGDOWN: number of hours when the interconnector is congested in the down direction
NBHCGTOTAL: number of hours when the interconnector is congested whatever the direction: sum of NBHCGUP and NBHCGDOWN
NBHNCGdPUP: number of hours when the interconnector is not congested in the up direction although a price difference occurs in the up direction
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NBHNCGdPDOWN: number of hours when the interconnector is not congested in the down direction although a price difference occurs in the down direction
NBHNCGdPTOTAL: sum of NBHNCGdPUP and NBHNCGdPDOWN
NBHRMPUP: number of hours when the ramping-up44 constraint is activated NBHRMPDOWN: number of hours when the ramping-down constraint is activated NBHRMPTOTAL: sum of NBHRMPUP and NBHRMPDOWN
NBHrFL45: number of hours when the flow is reduced compared to the reference run.
NBHzFL: number of hours when the flow is zero in the current run and is not zero in the reference run.
c. Net Position Indicators
For each biddinga area and each run, the net position indicators are calculated:
Total Pos NP: sum of net position for hours when net position is positive Total Neg NP: sum of net position for hours when net position is negative Total NP: sum of Total Pos NP and Total Neg NP
CWE NP: sum of net positions of CWE bidding areas for each hour Nordic NP: sum of net positions of Nordic46 bidding areas for each hour For each CWE bidding area, a NWE-NP is calculated as follows for each hour:
NWE-NP = NP – FlowExportedToNonCWE + FlowImportedFromNonCWE
The NWE-NP indicator is the sum of the hourly NWE-NP. This NWE-Net Position represents the net position of the CWE bidding areas after correction of the exchanges from/to other non-CWE bidding areas.
d. Price Indicators
The following indicators are calculated for each Run:
• percentage of hours with CWE convergence of prices
• percentage of hours with Nordic47 convergence of prices
• percentage of hours with Baltic48 convergence of prices
• percentage of hours with price convergence between CWE and Nordic bidding areas
• percentage of hours with price convergence between CWE and GB bidding areas
• percentage of hours with converging prices between bidding areas at line ends
• percentage of hours with full convergence of prices
44 This is not directional and refers to the sign of flow variation: ramping-up (resp. –down) constraint limits the increase (resp.
decrease) of flow from one hour to another.
45 This indicator is calculated only for interconnectors subject to loss factor for some runs.
46 Only bidding areas in Sweden, Norway, Denmark and Finland.
47 Only bidding areas in Sweden, Norway, Denmark and Finland.
48 Only EE; ELE; ELI bidding areas.
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