Relations with electricity sector operators

Given that service provided under concession agreements accounts for the bulk of the company's activities and revenues, Terna's customersBusinesses or distribution companies, wholesalers and the final buyers of electrical energy. are primarily electricity sector operators. They apply to Terna to access the transmissionElectricity transport and transformation activities along the interconnected high- and very high-voltage grid forthe purposes of delivery to customers, distributors, and recipients of self-produced energy. and dispatchingThe activity aimed at issuing provisions for the coordinated use and operation of production plants, thenational transmission grid, the grids connected to the same, and ancillary services of the electricity system. service. Terna operates under concession agreements since the National Transmission Grid is a monopoly.

The commercial relations that the operators establish with Terna are therefore regulated by the sector Authority and many of their aspects are defined in the Grid Code. In addition to following the regulatory framework, Terna maintains a constant focus on the operators' requirements, exchanging ideas and collaborating to define solutions that could lead to amendments to the Grid Code in compliance with specified procedures.

The commercial transactions in which Terna acts as concession holder concern the transmission and dispatching services. In the transmission service, operators connected to the NTG that inject electricity to the grid (power stationThe part of a grid which is concentrated and closed in a specified site, and used for switching electrical energyamong the lines of a grid, for transferring the electrical energy between grids with different levels of voltage,and for transforming the electrical energy to the lowest voltage usable by the user. owners) and those that withdraw electricity (distributors), pay Terna a transit fee for grid usage. In the dispatching service, Terna aims at ensuring a constant balance between electricity injection and withdrawal at all times. In the event of deviations from forecasts, Terna implements measures to maintain correct voltage and frequencyThe number of oscillations per second, in which the value of the alternating current, such as voltage, variesfrom positive polarity to negative polarity. It is measured in Hertz (Hz).Fringe BenefitCompensation in kind, meaning benefits which do not consist in the payment of money, but the use of aservice or an object: such as the company canteen, lunch vouchers, company car or mobile telephone. levels across the entire grid. This activity is fundamental for the electricity service as it allows the successful conclusion of electricity sales and purchase transactions and through calculation of the physical batches actually injected and withdrawn it allows for calculating deviations from contract obligations. The counterparties of this service (dispatching users, according to the Grid Code) are those responsible for the injection and withdrawal units, who sell or buy electricity through contracts entered directly between them (bilateral contracts) or through the electricity exchange market.

The dispatching users are, for injections, the producers or their delegates, for withdrawals, end customers or their delegates and the Single BuyerA stock company established in 2000 by the National Transmission Grid Operator (GRTN) to guaranteeCaptive Customers the supply of electrical energy under conditions of continuity, security and efficiencyof the service. The Single Buyer guarantees the application of a single national tariff to these customers.. Terna and the dispatching users enter into contracts which govern their mutual obligations, in compliance with the Grid Code and with the provisions of the Authority for Electricity and Gas.

On the basis of bilateral electricity purchase and sales contracts or offers to purchase or sell energy submitted to the electricity marketThe system of wholesale selling of electricity, which determines which power generation systems or plants willbe used to meet the demand at any moment, and determines the price of energy at that specific moment., each operator takes on commercial obligations to inject or withdraw energy for each hour of the following day, according to a binding schedule. If real-time differences should arise between these obligations and the actual values of energy injected or withdrawn, they will be settled by Terna, who is responsible for activating resources to offset the imbalances.

Terna invoices such unbalances to the dispatching service users according to rules established by the sector authority. To allow the users involved to rapidly check and verify the invoices, Terna has set up a special reserved-access section in its website, where each user can access his metering data.

The website also explains how to contact specific departments within Terna to request clarification or to report discrepancies. By setting up this direct contact with the electricity operators with which it has business relations, Terna pursues a relationship based on transparency, fairness and, within the limits imposed by sector regulations, attention to the customer.

During 2007 and in compliance with the regulations and the provisions of the Grid Code, Terna extended to all the distributing companies directly connected with the National Transmission Grid the subscription to the Agreement for regulating the electricity transmission service. The process that began in 2006 with the principal distributing company ended with the signing of an Agreement by all the 21 distributing companies connected to the National Transmission Grid. The Agreement introduced as its first new element the right to telemetering on the part of Terna aimed at regularly verifying the electricity that is certified by the distributing companies for applying the electricity transmission fee and at processing the actual report of the high voltage grid. As of today, telemetering coverage is equal to approximately 95% of the total.

Furthermore, signing the Agreements also includes appropriate financial guarantees for covering expenses deriving from the application of transmission costs on the National Transmission Grid and has allowed reducing the counterpart risk for Terna.

In 2007, as in the previous years, Terna continued to provide resources for the load interruptionCondition in which the voltage of the terminals delivering electrical energy for a user is lower than 1% of therated voltage. service in order to maintain the safe operationThe methodical use of power plants and accessories according to procedures codified in the implementationof the decisions regarding the operation of the Grid. Operation includes:• the running of the plants in order to carry out Terna’s orders and autonomous deliveries; • emergency assistance following fault or anomalies; • operations for going offline and for the security of the plants; • the monitoring of the status of the plants; • plant inspections. of the National Electricity SystemThe national electricity system comprises the total of production plants, transmission and distribution grids,auxiliary services and interconnection and dispatching devices located in the Italian territory. in case resources available on the dispatching services market were to be insufficient. The load interruption service is provided by end customers having the technical requirements and that are available to load interruptions. This is regulated according to the terms of the Grid Code and to the provisions of Sector Authorities.


Economic nature


Number of subjects




To be Interrupted
Interruptible users




Transmission fee
Distributors directly connected to the NTG




Transmission fee
Owners of power stations




Dispatching fees
Injecting dispatching users (Producers and Traders)




Withdrawing dispatching users (Traders and final customers including the Single Buyer)




1. The figure refers to the number of actual units located in Italy as of the month of December of each year.
2. Between December 2005 and December 2006 the number of operators subject to invoicing of the grid transmission fee for producers rose significantly. This fact was based on two causes: 1) entrance into operation of nearly 200 new small productionGeneration of electrical energy, in any way. plants (power < 10 MVA); 2) the completion of a census regarding invoicing of the grid transmission fee of small plants (power < 10 MVA) which even though quite numerous, only represent 1% of the total energy subject to grid transmission fees.
In 2007, the majority of small plants was included into the GSE contracts that keeps relations with Terna. Overall, 160 operators deal directly with Terna for the transmission service.
3. In the 2005 Sustainability Report, only injecting dispatching users were considered that owned significant production units (54).


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