Services for our customers – maximum transparency for maximum grid security in Europe.

The establishment of a common grid model (CGM) is the basis for every single evaluation of transmission system security. The European CGM is tailored to the requirements of the most important services of an RSC and consists of detailed input and forecast data on generation, consumption and network connectivity for all TSOs.  The data is provided by the TSOs in the form of their individual network models (IGMs) and other specific information. The RSC must check the quality of the IGMs and integrate them into the CGM in accordance with predefined rules, many of which are repeated hourly.

The legal basis for the CGM facility is provided by the Network Guidelines (EU) 2015/1222 and 2017/1487, which are described in the CGM Methodology.

Since the operational planning process is based exclusively on forecasts of the transmission grid, the planning measures must also be carried out where market results are not yet available. In this case, the necessary data is generated and optimally aligned in order to obtain a consistent picture of the forecast situation. For this purpose, the RSCs generate forecasts for the net position of each bidding zone, i.e. the balances of all import and export transactions, which are then included in the capacity calculation.

The aim of the CSA is to identify possible security restrictions after the market closure based on the so-called N-1 security principle, which is the common security standard for TSOs throughout Europe. The N-1 criterion defines that, in a given situation, the transmission grid remains in a safe state even if one of the available transmission elements is lost. Safety is given if, after entering the N-1 situation, the electrical parameters of voltages, currents and system stability criteria remain within the defined limits. If safety restrictions are detected, countermeasures can be identified and validated with the affected TSOs, for example:

• Change switching configurations based on Outage Planning Coordination Process (OPC) results
• Tapping of power flow control devices such as phase-shifting transformers or
• Redispatch actions involving the simultaneous increase and decrease of generation feeds in different network areas.

CSA activities currently encompass the time frames of the Day-ahead Congestion Forecast (DACF) process, which begins in the late afternoon of the penultimate day after market close, and the Intraday Congestion Forecast (IDCF) process, which begins before midnight and includes an hourly rolling forecast of all remaining hours of a calendar day.

The decision-making process with the TSOs is organised via teleconferences with our customers initiated by TSCNET during the DACF and IDCF processes, a so-called “DOPT” (Daily Operational Planning Teleconference) and “IDOPT” (IntraDay Operational Planning Teleconference).

Since 2013, TSCNET and the majority of its shareholders have introduced a special arrangement for coordinated redispatch actions, known as Multilateral Remedial Actions (MRAs), to meet complex security restrictions that require corrective measures in the networks of more than two TSOs at the same time. This MRA concept also introduced the first Inter-TSO cost sharing principle for costly remediation measures in Europe.

The identification and implementation of MRAs is coordinated by TSCNET during the DACF and IDCF phases, while cost sharing calculation is performed by TSCNET on the basis of an revision-proof tool and process.

The implementation of the future CSA processes according to the provisions of the Network Guidelines (EU) 2015/1222 and 2017/1485 will be prepared for the CORE and Italy North CCRs.

In the function of a coordinated capacity calculator we work out the cross-border transmission capacities for each relevant Capacity Calculation Region (CCRs) based on the methods approved by the national regulatory authorities and a tailor-made common network model.

This will provide the market with optimum capacity as a basis for cross-border transmission trade. After allocating capacity, TSCNET validates the net positions of the bidding zones and calculates the relevant bilateral cross-border exchanges as the basis for nominating trading plans with the TSOs.

In developing the CCC for the CCRs, TSCNET follows the provisions of the Network Guidelines (EU) 2015/1222 and 2016/1719.

Today, TSCNET operates the CCC for the Central Western Europe Region (CWE) for the provision of day-ahead market capacity, while the provision of intraday capacities in the CWE region and the CCR Italy North is still in the experimental stage. In addition, the implementation of a flow-based day-ahead and a long-term CCC is being developed for CORE CCR.

The transmission grid has been expanded over decades and further grid expansions and reinforcements are crucial for a successful energy transition and a secure power supply. Since generation and transmission systems such as overhead lines, transformers, breakers or measuring devices have a service life of between 20 and 80 years, depending on their type and operating load, regular maintenance work is required to keep the systems “in shape”.

Both the network design and the maintenance work usually require direct access by TSO personnel to the equipment, which requires the equipment to be shut down to ensure safe working conditions. Network expansions also require separation of sections of existing transmission elements to connect new equipment. During this time, the remaining part of the grid may be less able to absorb electrical energy flows, which must be taken into account when assessing system safety.

Construction and maintenance work is part of the TSOs’ annual work programmes, for which the necessary asset services must be scheduled and contractually agreed. As a rule, this planning takes place in the second half of a calendar year in preparation for the following year.

The OPC process collects all planned shutdowns of transmission and relevant generation elements and evaluates whether their simultaneous overlay meets the requirements for system security. If necessary, TSCNET identifies and coordinates remedial actions with the TSOs and other RSCs in order to optimise the outage plans and to ensure that the planned measures are implemented as effectively as possible.

The OPC process provides information about possible incompatibilities in the failure planning, i.e. the risk that the simultaneously planned failures of different elements are not possible and whether these incompatibilities can be eliminated, e.g. by a timely postponement of work or a changed sequence of activities in a region.

The final outage plan will be incorporated into the CCC and CSA processes. Therefore, the outlook takes into account the forecast horizon of more than one year to a few days before commissioning and is repeated cyclically to cope with the new conditions arising over time.

The OPC process at TSCNET follows the requirements of the Network Directive (EU) 2017/1485 and went into operation at the beginning of 2018 and is continuously being improved. The results of the OPC process are evaluated in a so-called weekly operational planning teleconference (WOPT) with our customers.

Because of the lack of storage facilities, electricity must be generated exactly when it is needed. A secure supply in Europe therefore requires the availability of a minimum of installed generation capacity in order to reliably provide the necessary supply capacity. Sudden power outages due to technical failures along the complex process chain, e.g. at thermal generation plants, can reduce the availability of generation capacity. With adequate power generation, the installed generation capacity available at operational level must always be higher than the consumption served.

Information on sufficient available generation capacity is a prerequisite, but not entirely sufficient, for ensuring a secure supply of electricity, as the grid may have restrictions on the transport of the generated electricity to the place of consumption. Therefore TSOs need an early assessment of whether market liquidity is limited or whether the regional distribution of generation capacity and consumption leads to congestion. The earlier this information is available, the better they can prepare for such an exceptional situation.

As an RSC based on the Network Directive (EU) 2017/1485, we provide TSOs with detailed and continuously updated SMTA forecasts based on information on the availability, consumption and expected state of transmission corridors with forecast horizons between weeks and a few days in advance.

The SMTA process at TSCNET has been running since early 2018 and is being continuously improved. The results are discussed with our customers in a Weekly Operational Planning Teleconference (WOPT).

The TSOs operate the grid on the basis of common rules for the coordination of power flows and for compliance with the grid frequency around the nominal value of 50Hz. These rules are intended to prevent the power grid from reaching an emergency state or even to prevent a power failure with its major risks. It is therefore the duty TSOs to take care of these unlikely situations and to draw up system defence and recovery plans in order to maintain and restore the functioning of the transmission grid.

The Commission Regulation (EU) 2017/2196 establishing a network code for emergency and recovery measures in the electricity sector requires RSCs to review the TSO’s restoration plans for consistency and to provide a technical report for all TSOs to be forwarded to the national regulatory authorities and ENTSO-E to monitor implementation.

The operational planning process is well structured between TSOs and RSCs and aims at a secure transmission system operation under standardized framework conditions and risk parameters.

However, the coincidence of extraordinary circumstances such as extreme weather conditions or the sudden unavailability of a larger part of the installed generation capacity can endanger network security and thus lead to a critical grid situation (CGS).

In order to identify this risk level at an early stage, the RSCs and the TSOs work together on forecasting methods to cover time windows before market results are available so that they have sufficient time to react if necessary. In addition, the RSCs support the TSOs in organising communications in advance and during the operational planning phase if a CGS is expected and appropriate remedial actions need to be prepared.