System Development

The Ten-Year Network Development Plan:
Building Europe’s future power system

The Ten-Year Network Development Plan (TYNDP) is the outcome of a two-year process, starting with the development of scenarios outlining how the European power system might look in 2030 and 2040. Over 200 experts Europe-wide carried out regional exploration studies and pan-European analyses, and assessed projects to reinforce the grid, submitted through a European-wide call for candidatures.

Imagine and model future electricity and gas systems scenarios

ENTSO-E and ENTSOG published their second joint Scenario Report for TYNDP 2020 in November 2019. Stakeholder feedback was collected through a public consultation on the joint scenarios held between November 2019 and January 2020, and through a public workshop on the draft TYNDP 2020 Scenarios held on 5 December 2019 in Brussels. The workshop presented the scenarios, explained how they were developed and detailed the next steps13.

For the first time, the new set of scenarios are no longer formally attached to the TYNDP but have become a standalone product of both ENTSO-E and ENTSOG. Although the TYNDP is a major user of these scenarios, and the development processes of the TYNDP and scenarios are closely interlinked (see development cycle in the following section), ENTSO-E wants to highlight with this measure how the scenarios can and should be used for studies on all future aspects of the European energy system (internal and external to ENTSO-E and ENTSOG).

13 The final 2020 scenario report was published in June 2020.

Key dates & documents

12 Nov 2019

Publication of the Joint Scenario Report for TYNDP

25 Nov 2019 – 22 Jan 2020

Public consultation on the joint TYNDP Scenarios

5 Dec 2019

Public workshop on the draft TYNDP 2020 Scenarios

Three Scenarios

National Trends is the central scenario based on the draft NECPs, as well as on further national policies and climate targets already stated by the EU member states. It is compliant with the EU’s 2030 Climate and Energy Framework (32 % renewables, 32.5 % energy efficiency) and EC 2050 Long-Term Strategy, with an agreed climate target of 80–95 % CO2 reduction compared to 1990 levels.
Global Ambition is a scenario compliant with the 1.5° C target of the Paris Agreement, also considering the EU’s climate targets for 2030. It considers a future that is led by the development in centralised generation. Economies of scale lead to significant cost reductions in emerging technologies such as offshore wind, but imports of energy from competitive sources are also considered as a viable option.
Distributed Energy is a scenario compliant with the 1.5° C target of the Paris Agreement, also considering the EU’s climate targets for 2030. It takes a de-centralised approach to the energy transition. A key feature of the scenario is the role of the energy consumer (prosumer), who actively participates in the energy market and helps to drive the system’s decarbonisation by investing in small-scale solutions and circular approaches.

Supply and demand data collected from both gas and electricity TSOs are used to build “National Trends”, the central policy-based scenario, reflecting Member States’ draft National Energy and Climate Plans (NECPs) and recognising EU climate targets. The ”Global Ambition” and “Distributed Energy” Scenarios are developed as full energy scenarios (not limited to gas and electricity); they are built in line with the Paris Agreement target of limiting the increase in the global average temperature to 1.5 °C and considering the efforts of the EU-28 to reduce emissions to net-zero by 2050.

For the National Trends scenario, country-specific data were collected for 2030 and 2040 (when available for electricity) in compliance with the TYNDP timeframe. For gas, further assumptions have been made to compute the demand for 2050 on an EU28-level. Both the Distributed Energy and Global Ambition scenarios are developed on a country-level until 2040 and on an EU28-level until 2050.

The Ten-Year Network Development Plan

The TYNDP is a pan-European network development plan, providing a long-term vision of the power system. A legally mandated deliverable (Article 30(1), Regulation 943/2019), published by ENTSO-E every two years, it is the foundation of European grid planning and the basis for transmission projects that are eligible to be labelled as “Projects of Common Interest” (PCI).

The elaboration of each TYNDP is a two-year process:


Figure 2 – TYNDP two-year process

Each scenario’s impacts on energy markets and networks are analysed with the help of tailored modelling tools. Thanks to the models, ENTSO-E can explore various energy market needs and the corresponding power grid configurations. We can therefore understand, make transparent and better explain which parts of the network infrastructure are fit for purpose and which need to be reinforced or supported by alternative solutions or technologies. The main role of TYNDP is thus to identify where investment in the electricity system would help releasing the expected transmission constraints, and by doing so providing the adequate infrastructure. This is done in two stages: performing a system needs analysis that begins with a theoretical overview of the optimal set-up to allow the decarbonisation of the EU power system at the lowest cost, followed by a call for transmission and storage projects (under different stages of development) across Europe, complemented by an analysis of their performance under different scenarios.

In continuation of the work initiated two years ago, TYNDP 2020 highlighted the particular needs for strengthening the existing transmission grid as a prerequisite for a secure and stable power system and for achieving the European climate targets. The missing grid capacity for the rapidly increasing Renewable Energy Sources (RES) capacity translates into curtailment and congestion as well as expensive and CO2-intensive redispatch measures, as power would not be able to flow from lower-cost areas to more expensive ones. Therefore, the cost of no grid could largely exceed the cost of grid reinforcement. Alternatives to grid investments form part of the approach, such as storage and demand side measures.

Key dates & documents

17 Jun – 14 July 2019

Public consultation on the Guidance for project ­promoters

22 Oct – 22 Nov 2019

Submission of storage and infrastructure projects

174 projects submitted:

  • 148 transmission
  • 25 storage
  • 1 not in line with criteria

A total of 174 projects were submitted to the TYNDP 2020 during the submission window that took place October–November 2019. As a result, 148 transmission projects and 25 storage projects compose the TYNDP2020 projects portfolio. Only one project was found not to comply with the criteria. ENTSO-E has verified the conformity of all submissions with the criteria for admission in the TYNDP2020 set in the Guidance for project promoters – Transmission and storage projects Criteria for applications and their treatment in the TYNDP2020.

Electricity and gas: modelling the interlinkage

Highly volatile generation and possible low utilisation rates of RES require high system flexibility to optimally utilise the installed renewable capacity while avoiding potential overrated system development. The difference between local generation and consumption (surplus), in case it is not possible to develop an infrastructure which provides sufficient transmission capacity, leads to the need for different instruments, one of which could be the conversion to other energy forms or carriers. To this end, Power to Gas and other P2X (e.g. Power to Liquid, Power to Heat, etc.) may have the potential to efficiently provide a certain degree of flexibility and thus reduce the cost of the decarbonised energy system.

ENTSO-E has been working with ENTSOG since 2015 in developing a common set of scenarios. ENTSO-E and ENTSOG further investigated the interlinkage between gas and electricity scenarios and infrastructure project assessment with a joint focus study, examining all possible interactions between the gas and electricity sectors, and relevant gas and electricity infrastructure interactions. The key element of this model is the joint development of scenarios that constitute the basis for the cost–benefit analysis (CBA) of gas and electricity infrastructure projects. Once the scenarios have been commonly established, the submitted model proposes that ENTSO-E and ENTSOG perform the CBA of infrastructure projects based on their specific tools and methodologies.

Key dates & documents

Sep 2019

Publication of the joint ENTSO-E and ENTSOG ­Focus Study on Interlinkage between Gas and ­Electricity Systems

The study was supported by an ad hoc group of interested stakeholders representing European organisations and was also discussed with ACER and the European Commission in 2019. The “Focus study on gas and electricity interlinkage” report concludes that interactions between gas and electricity systems are captured by the TYNDP scenarios assumptions. The report also identified specific cases where additional interactions can be related to infrastructure projects. For TYNDP 2020, ENTSO-E and ENTSOG have already improved their scenario building process to account for gas and electricity interactions and will continue to build on stakeholders’ feedback to further improve the new editions.

The cost–benefit analysis methodology

The assessment of infrastructure and storage projects performed in the TYNDP uses a CBA methodology drafted by ENTSO-E, in consultation with stakeholders. The methodology when ready is proposed to the European Commission, who issues an opinion confirming or rejecting the proposal. The CBA results are also used as the basis of the PCI selection process. The main objective of the CBA methodology is to provide a common and uniform basis for the assessment of projects with regard to their value for European society.

ENTSO-E developed a third version of the CBA methodology, which improves on the previous versions in its consideration of security of supply, socioeconomic welfare and storage. The CBA 3.0 was submitted to a formal public consultation process from 25 October until 9 December 2019. A workshop to present and discuss the CBA 3.0 took place in Brussels on 8 November 2019.

Key dates & documents

25 Oct – 9 Dec 2019

Public consultation on the CBA methodology 3.0 ➔ Comments received and ENTSO-E’s assessment

8 Nov 2019

Public presentation of the 3rd CBA guideline

Ensuring system adequacy

“Resource adequacy” can be defined as the continuous balance between net available generation, on the one hand, and net load levels, on the other. Assessing the ability of a power system to cover demand in all conditions is part of the TSOs’ tasks, and, consequently, one of ENTSO-E’s most important mandates.

Due to the increasing level of variable RES in the European power system and the associated challenges for system development and operation, a pan-European analysis of resource adequacy has become ever more important. Cooperation across Europe is necessary to accelerate the development of common methodological standards, i.e. a common ‘language’ is required to perform these studies. Resource adequacy requires advanced methodologies to capture and analyse rare events with adverse consequences for the supply of electric power.

Rescource Adequacy

Figure 3 – Resource Adequacy

The Mid-term Adequacy Forecast

To account for a growing number of disruption risks related to the evolution of the energy mix – the growing development of RES, reduction of conventional power plants, availability of interconnection capacity – Europe needs a regular assessment of the adequacy situation, at time horizons of up to ten years ahead. The “Mid-term Adequacy Forecast” (MAF) aims to provide a pan-European adequacy assessment of the risks to security of supply and the need for flexibility for the coming decade. The MAF is based upon state-of-the-art probabilistic analysis, conducted using sophisticated market modelling tools. It contributes to the harmonisation of resource adequacy methodologies across Europe by being a reference study for European TSOs. The MAF aims to provide stakeholders with the data necessary to make informed, quality decisions and promote the development of the European power system in a reliable, sustainable and connected way.

Data granularity and quality have improved significantly in MAF 2019. For example, for the first time, unit-by-unit information concerning thermal generation was collected and implemented in the models. In addition, the climate database was extended to include 35 years of hydrological data, and a new, improved methodology was introduced to construct hourly demand time series. Five different market modelling tools were used to assess the entire European perimeter based on comprehensive data for two target years: 2021 and 2025. The MAF 2019 updates, and provides a comparison to, the results of MAF 2018, which focused on the target year 2020. The second target year, i.e. 2025, was chosen as a pivotal year for evaluating adequacy due to significant reductions in coal and nuclear capacity expected between 2021 and 2025. Generally, the results of MAF 2019 indicate low risks of inadequacy in the system, if input assumptions of the assessment materialise, with the exception of islands and a few continental market zones.

The CEP places resource adequacy in a central position in the European energy policy context. It extends the scope of the ENTSO-E MAF and develops it further into a new Pan-­European Resource Adequacy Assessment. As provided for by Article 23 of the Electricity Regulation, in 2019 ENTSO-E developed a methodology for a European resource adequacy assessment and a methodology for calculating the Value of Lost Load (VoLL), the Cost of New Entry (CONE) and the Reliability Standard. These methodologies were submitted to public consultation and presented to stakeholders at a workshop held in December 2019.

Key dates & documents

21 Nov 2019

Publication of the MAF 2019

19 Nov 2019 – 13 Jan 2020

Public consultation on the MAF 2019

Key dates & documents

5 Dec 2019 – 30 Jan 2020

Public consultation on the methodology for a ­European resource adequacy assessment

5 Dec 2019 – 30 Jan 2020

Public consultation on the methodology for calculating the VoLL, the CONE and the Reliability Standard

16 Dec 2019

Stakeholder workshop on European resource ­adequacy assessment methodologies

The Seasonal Outlooks

ENTSO-E’s Seasonal Outlooks (Article 30(1)f, Regulation 943/2019) are a pan-European, system-wide analysis of risks to electricity security of supply. Analyses are performed twice a year to ensure a good view regarding the summer and winter and to present TSOs’ views on the risks to security of supply and the countermeasures they plan for the coming season, either individually or in cooperation. ENTSO-E thus publishes its Summer outlook before 1 June and its Winter Outlook before 1 December. Each outlook is accompanied by a review of what occurred during the previous season.

The outlooks are performed based on the data collected from TSOs and using a common methodology. Moreover, ENTSO-E uses a common database in its assessment, the Pan-European Climate Database, (PECD), to determine the levels of solar and wind generation at a specific date and time. ENTSO-E analyses the effect on system adequacy of climate conditions, evolution of demand, demand management, evolution of generation capacities, and planned and forced outages.

ENTSO-E is seeking to improve the methodology used in the seasonal outlooks, to further align with the one used for the MAF. This implies a switch from a mostly deterministic approach to a full probabilistic approach with hourly calculations at the Pan-European level. The change is being done following a step-by-step process, as it requires the implementation of new tools, methodologies and models.

Moreover, to improve the coordination with the week-ahead adequacy assessment performed by RSCs, in 2019 ENTSO-E worked on a proposal for a methodology for assessing seasonal and short-term adequacy, namely monthly, week-ahead to at least day-ahead adequacy (Art. 8 of the Risk Preparedness Regulation 2019/941). ENTSO-E has also developed a proposal for Methodology for identifying regional electricity crisis scenarios (Art. 5 of the Risk ­Preparedness Regulation). For both risk preparedness ­methodologies, stakeholders were involved through a public consultation that took place from 8 July to 8 October 2019, and a webinar held on 5 September 2019.

Key dates & documents

8 Jul – 8 Oct 2019

Public consultation on the risk preparedness methodologies provided for by art. 5 and 8 of Reg. 2019/941

5 Sep 2019

Webinar on Risk Preparedness Methodologies

27 Nov 2019

Publication of the Winter Outlook 2019/2020

Connection codes: Integrating renewables

The objectives of the three Connection Network Codes (CNCs) – Demand Connection Code (DCC), Requirements for Generators (RfG), and High Voltage Direct Current Connections (HVDC) – are threefold: first, to ensure the integration of decentralised RES and the increased demand response into the power system. Second, to facilitate the internal electricity market by levelling the playing field of grid users in different member states. Third, to increase competition among equipment providers by harmonising the requirements with what they need to comply in different markets.

The implementation of connection codes is the responsibility of each EU member state. In this context, ENTSO-E acts as a platform to maintain and eventually amend CNCs; share information, guidance, and best practices for national implementation processes; and monitor their progress, especially through the development and delivery of non-binding written guidance – Implementation Guidance Documents (IGDs) – to its members and other system operators. The development of IGDs is fuelled by discussions with stakeholders from the drafting phase onward, via dedicated expert groups and the Grid Connection Stakeholder Committee.

Implementation monitoring

ENTSO-E monitors the implementation activities in each country via its Active library, looking in particular at divergences in national implementation. The “Monitoring report on Connection Network Codes Implementation” was published in December 2019.

Key dates & documents


ENTSO-E Annual Report 2019

This Annual Report covers the period from January to December 2019. It focuses on the legal mandates given to ENTSO-E. Activities covered in this report have been performed thanks to the 42 members of ENTSO-E who provide its financial resources and whose staff provides expertise to the Association.


  1. System Operation
  2. Market
  3. System Development
  4. Transparency Regulation
  5. Research, Development and Innovation
  6. Cybersecurity, Interoperability and Data
  7. TSO–DSO partnership and demand side flexibility
Download the full report (PDF, 4.2 Mb)