allocation constraints — the constraints to be respected during capacity allocation to maintain the transmission system within operational security limits and have not been translated into cross-zonal capacity or that are needed to increase the efficiency of capacity allocation 6.

capacity calculation region — the geographic area in which coordinated capacity calculation is applied 3.

capacity management module — a system containing up-to-date information on available cross-zonal capacity for the purpose of allocating intra-day cross-zonal capacity 40.

central counter party — the entity or entities with the task of entering into contracts with market participants, by novation of the contracts resulting from the matching process, and of organising the transfer of net positions resulting from capacity allocation with other central counter parties or shipping agents 42.

clearing price — the price determined by matching the highest accepted selling order and the lowest accepted buying order in the electricity market 31.

common grid model — a Union-wide data set agreed between various TSOs describing the main characteristic of the power system (generation, loads and grid topology) and rules for changing these characteristics during the capacity calculation process 2.

congestion income — the revenues received as a result of capacity allocation 16.

contingency — the identified and possible or already occurred fault of an element, including not only the transmission system elements, but also significant grid users and distribution network elements if relevant for the transmission system operational security 10.

continuous trading matching algorithm — the algorithm used in single intraday coupling for matching orders and allocating cross-zonal capacities continuously 29.

coordinated capacity calculator — the entity or entities with the task of calculating transmission capacity, at regional level or above 11.

coordinated net transmission capacity approach — the capacity calculation method based on the principle of assessing and defining ex ante a maximum energy exchange between adjacent bidding zones 8.

day-ahead firmness deadline — the point in time after which cross-zonal capacity becomes firm 35.

day-ahead market gate closure time — the point in time until which orders are accepted in the day-ahead market 36.

day-ahead market time-frame — the time-frame of the electricity market until the day-ahead market gate closure time, where, for each market time unit, products are traded the day prior to delivery 34.

economic surplus for the single day-ahead or intraday coupling — the sum of (i) the supplier surplus for the single day-ahead or intraday coupling for the relevant time period, (ii) the consumer surplus for the single day-ahead or intraday coupling, (iii) the congestion income and (iv) other related costs and benefits where these increase economic efficiency for the relevant time period, supplier and consumer surplus being the difference between the accepted orders and the clearing price per energy unit multiplied by the volume of energy of the orders 46.

firmness — a guarantee that cross-zonal capacity rights will remain unchanged and that a compensation is paid if they are nevertheless changed 44.

flow-based approach — a capacity calculation method in which energy exchanges between bidding zones are limited by power transfer distribution factors and available margins on critical network elements 9.

force majeure — any unforeseeable or unusual event or situation beyond the reasonable control of a TSO, and not due to a fault of the TSO, which cannot be avoided or overcome with reasonable foresight and diligence, which cannot be solved by measures which are from a technical, financial or economic point of view reasonably possible for the TSO, which has actually happened and is objectively verifiable, and which makes it impossible for the TSO to fulfil, temporarily or permanently, its obligations in accordance with this Regulation 45.

generation shift key — a method of translating a net position change of a given bidding zone into estimated specific injection increases or decreases in the common grid model 12.

individual grid model — a data set describing power system characteristics (generation, load and grid topology) and related rules to change these characteristics during capacity calculation, prepared by the responsible TSOs, to be merged with other individual grid model components in order to create the common grid model 1.

intraday cross-zonal gate closure time — the point in time where cross-zonal capacity allocation is no longer permitted for a given market time unit 39.

intraday cross-zonal gate opening time — the point in time when cross-zonal capacity between bidding zones is released for a given market time unit and a given bidding zone border 38.

intraday market time-frame — the time-frame of the electricity market after intraday cross-zonal gate opening time and before intraday cross-zonal gate closure time, where for each market time unit, products are traded prior to the delivery of the traded products 37.

market congestion — a situation in which the economic surplus for single day-ahead or intraday coupling has been limited by cross-zonal capacity or allocation constraints 17.

market coupling operator (MCO) function — the task of matching orders from the day-ahead and intraday markets for different bidding zones and simultaneously allocating cross-zonal capacities 30.

market time — central European summer time or central European time, whichever is in effect 15.

matched orders — all buy and sell orders matched by the price coupling algorithm or the continuous trade matching algorithm 22.

matching — the trading mode through which sell orders are assigned to appropriate buy orders to ensure the maximisation of economic surplus for single day-ahead or intraday coupling 20.

net position — the netted sum of electricity exports and imports for each market time unit for a bidding zone 5.

nominated electricity market operator (NEMO) — an entity designated by the competent authority to perform tasks related to single day-ahead or single intraday coupling 23.

non-standard intraday product — a product for continuous intraday coupling not for constant energy delivery or for a period exceeding one market time unit with specific characteristics designed to reflect system operation practices or market needs, for example orders covering multiple market time units or products reflecting production unit start-up costs 41.

operational security limits — the acceptable operating boundaries for secure grid operation such as thermal limits, voltage limits, short-circuit current limits, frequency and dynamic stability limits 7.

order — an intention to purchase or sell energy or capacity expressed by a market participant subject to specified execution conditions 21.

physical congestion — any network situation where forecasted or realised power flows violate the thermal limits of the elements of the grid and voltage stability or the angle stability limits of the power system 18.

price coupling algorithm — the algorithm used in single day-ahead coupling for simultaneously matching orders and allocating cross-zonal capacities 28.

reliability margin — the reduction of cross-zonal capacity to cover the uncertainties within capacity calculation 14.

remedial action — any measure applied by a TSO or several TSOs, manually or automatically, in order to maintain operational security 13.

scenario — the forecasted status of the power system for a given time-frame 4.

scheduled exchange — an electricity transfer scheduled between geographic areas, for each market time unit and for a given direction 32.

scheduled exchange calculator — the entity or entities with the task of calculating scheduled exchanges 33.

shared order book — a module in the continuous intraday coupling system collecting all matchable orders from the NEMOs participating in single intraday coupling and performing continuous matching of those orders 24.

shipping agent — the entity or entities with the task of transferring net positions between different central counter parties 43.

single day-ahead coupling — the auctioning process where collected orders are matched and cross-zonal capacity is allocated simultaneously for different bidding zones in the day-ahead market 26.

single intraday coupling — the continuous process where collected orders are matched and cross-zonal capacity is allocated simultaneously for different bidding zones in the intraday market 27.

structural congestion — congestion in the transmission system that can be unambiguously defined, is predictable, is geographically stable over time and is frequently reoccurring under normal power system conditions 19.

trade — one or more matched orders 25.