The Masterplan Report

The general process used by Med-TSO members for coordinated planning is based on a consolidated procedure for the elaboration and assessment of a development plan of interconnection projects between the transmission systems of Med TSO countries with the aim of addressing the challenges of energy transition in the Mediterranean area.

To make such energy transition happen in a cost-effective and secure way, this portfolio of interconnection projects is assessed for a range of possible energy outlooks in terms of load and generation evolution, obtained through the development of adequate long-term scenarios.

Setting the path from the present situation to the reference time-horizon, these scenarios should provide a robust framework for grid development studies, based on which the interconnection projects of the MMP shall be assessed, with the implementation of a technical-economical approach taking the results of market and network studies as input.

Towards this goal, a "Methodology for the Long-term Network Development Plan" includes the following main actions:

• Definition of Mediterranean scenarios
• Definition of the list of future interconnection projects
• Creation of reference models of power systems at regional level in order to perform market studies
• Analysis of the network behaviour (load flow calculations) and the investments needed to fulfill the security requirements
• Cost-benefit analysis (CBA) for the new investments

3.1 Mediterranean scenarios and main assumptions

Lastly, but of greater relevance, differences appear in national energy and environmental policies and internal regulations driving the transition towards a greener energy future, with EU countries more advanced with respect to other Med-TSO members. If these disparities also affect the way in which the States approach their commitment vis-à-vis the Paris Agreement, a form of convergence can be found, looking at the overall trend, in the massive development of renewable energies - mainly solar and wind - among all the Mediterranean countries. Evaluations based upon these differences have led to the construction of three contrasting scenarios, which represent three possible evolutions of the Mediterranean electricity system by 2030.

Rationales for defining scenarios for the future of the Mediterranean power system

From a general perspective, building storylines and scenarios in the Mediterranean context requires the definition of a series of parameters that constitute the main drivers of the scenarios, as summarized below.


Three scenarios to address the evolution of the Mediterranean power system in 2030

Based on different hypotheses of the evolution of the most essential drivers affecting the Mediterranean electricity system, the main principles of the three different long-term scenarios can be described as follows.

INERTIAL SCENARIO (IN) - No breakthrough in the midterm

Under a moderate growth of Gross Domestic Production (GDP) and electricity consumption, this scenario basically complies with 2030 national objectives (in European Countries, this refers to those set in 2019 National Energy and Climate Plans), with international cooperation remaining scarce outside of the European context.

In the Inertial Scenario (IN), energy policies stick at local and national levels, also due to the persisting differences in the power sector regulation among Mediterranean areas and countries. RES development is moderately but steadily progressing, according to national energy policies, without a clear bias between small, distributed plants and large centralized ones. With the exception of very few countries with strong incentive policies, electric vehicles are also progressing slowly, as well as electrification of other sectors and energy efficiency measures.

PROACTIVE SCENARIO (PR) - Bottom-up, boost in distributed generation and electrical devices at consumer level

Under a marked increase of GDP and of electricity consumption, this scenario is characterized by a higher ambition towards a more sustainable energy sector, resulting in intensified RES development (compliant with EU climate neutrality in 2050), but little international cooperation among MENA countries and weak integration of energy policies.

In the Proactive Scenario, RES development is mainly driven by local solutions and adapted regulations and/or incentives that support widespread investments at consumer and prosumer levels, integrated with residential and building energy management. In this scenario, some countries are expected to accelerate the adoption of electric vehicles and other electrification systems, as well as the implementation of energy efficiency measures. Asymmetries between countries are still relevant. Distributed generation might mitigate internal congestion in some cases , however, interconnections remain fundamental to enable the integration of higher shares of RES, while guaranteeing security of supply.

MEDITERRANEAN AMBITION SCENARIO (MA) - Top-down boost for international cooperation and utility-scale developments

Under a marked increase of GDP and of electricity consumption, there is a greater ambition for a more sustainable energy sector, resulting in intensified RES development (compliant with EU climate neutrality in 2050), accompanied by improved cooperation on a Green Transition, in terms of policy integration, financing, industry, and technology transfer. This occurs across all Mediterranean shores, with a regional, multilateral approach relying on substantial improvements for what concerns energy policy implementation, harmonization of regulations and technical cooperation among grid operators.

In the Mediterranean Ambition scenario, strong RES development is based on utility-scale projects backed by institutional agreements and international cooperation, also for offtake agreements (e.g., Power Purchase Agreements). The abundance of CO₂-free energy also contributes to boosting new uses of electricity beyond heating and cooling technologies and to a moderate push towards energy efficiency. Complementarities between countries are relevant in this scenario, emphasized by potentially diverging individual paths in large project deployment.

Both the Proactive and Mediterranean Ambition scenarios are set to reach climate neutrality in Europe by 2050, but this occurs through two different and contrasting pathways: The Proactive scenario focuses more on renewable development through distributed technological options, while the Mediterranean Ambition scenario favors centralized low-carbon energy generation.

Table 1 outlines the relevance of key drivers and their metrics for the definition of the storylines of the three contrasting scenarios. The variability of the metrics allows a wide spectrum of potential future conditions to be fully assessed, thus increasing the accuracy of scenario building and network analysis.


It is important to highlight that the three Med-TSO long-term scenarios do not intend to forecast the future, nor to provide any quantification of probability associated with any of them. On the contrary, the scenarios explore a wide spectrum of trends within which the future will invariably fall, thus supporting the assessment of the costs and benefits of interconnection projects.

The need for a set of common technical parameters and principles

In addition to describing the scenario through drivers and storylines, the coherency of market studies is ensured through the determination of a common set of technical and economical parameters and principles:

• The principle of an efficient day-ahead market.
• The principle of equal fossil fuel wholesale prices across all Euro-Mediterranean countries.
• The principle of an economic value for CO₂ emissions resulting from electricity generation, applicable to all Mediterranean countries.

How Med-TSO scenarios are linked to other available scenarios

The perimeter of power system modelling includes the whole interconnected power system, which encompass both European and Mediterranean (extra-EU) countries. For the resulting Euro-Mediterranean power system, there is therefore a key issue in ensuring consistency among data provided by TSOs belonging to the perimeter of ENTSO-E, the association of European TSOs, and to Med-TSO.

To facilitate such consistency, the two associations have signed a designated cooperation agreement and have established a fruitful exchange of methodologies, models, and data. Globally, the scenario-building methodology used by Med-TSO is similar to that adopted by ENTSO-E, in particular, in relation to the scenarios proposed for use in the Ten-Year Network Development Plan (TYNDP) 2022. Therefore, the principle is to examine to what extent these drivers coincide and to proceed with the coupling of the scenarios, favouring the coherence of the drivers to the greatest possible extent. Following a driver-based method, the matching of a Med-TSO scenario with the most similar ENTSO-E scenario for European countries results in the synergies described below.


Although Med-TSO and ENTSO-E scenarios are logically aligned as summarized above, several inconsistencies might occur due to differences in the timings of the two processes, slightly different sets of inputs, and use of different models and methodological approaches (e.g., use of different climate years, assumptions for green gases, etc.).

Similar inconsistencies might also exist between Med-TSO's scenarios and those developed by TSOs at national level.

For more detailed information on methodologies, the reader is invited to consult the Med-TSO Scenarios Report.

The scenarios presented in this report were built collectively by the members of Med-TSO based on the context and prospects for the evolution of electricity systems in Mediterranean countries. Assuming this common framework, the data collection is performed following a bottom-up approach for the three scenarios.

Three Mediterranean countries have not directly contributed to the data collection: Israel, Syria, and Lebanon. For these countries, the detailed data were compiled based on public documents, for the three scenarios, while respecting their definition. Thus, the lack of a direct contribution from these countries is not considered to not weaken the collective quality and accuracy of the scenarios.

Commodity prices

Table 2 presents the fuel and commodity prices adopted by Med-TSO for modeling the Euro-Mediterranean Power System.


The operation and the evolution of the power system will increasingly rely on other sectors, like green gas and heat.

As a result, it is necessary to model the associated interactions. In Med-TSO's scenarios, interactions with electrolyzers are modelled based on hydrogen needs and uses, applying the widest range of system conditions and relying on Steam Methane Reforming (SMR) as a generic backup at a price equivalent to green hydrogen. In the merit order, electrolyzer activation prices stay between nuclear and CCGT generation prices. This ensures that hydrogen is only produced from electricity in periods of renewable and nuclear marginality, and that, on the other hand, the operation of electrolyzers does not induce an increase in fossil thermal production.

3.2 Proposed investment clusters and their rationale

The Mediterranean electricity network covers a vast and diversified area, characterized by a huge variability in terms of generation mixes, weather conditions, renewable generation potential, demand patterns, etc. Investment clusters and interconnection projects are therefore proposed by TSOs to solve or cover specific system needs that can vary significantly from one region to another. To support the identification of clusters, covered system needs have been classified into categories of project merits, as outlined in the following table. As explained in the following paragraphs, some of the project merits find a direct quantification in the benefits typically used in cost-benefit analyses. This is the case, for example, of the merits related to the first macro category: Welfare, Sustainability and Security of Supply, which includes the economic welfare generated by the given project, the reduced RES curtailment and associated reduced CO₂ emissions, and the reduced energy not supplied (ENS). Other merits are only assessed in qualitative terms and associated to project through symbols and specific descriptions.


The listed merits have been used by TSOs as a basis to propose cross-border interconnection projects to be assessed within the framework of the TEASIMED project. The table below presents the list of the 19 proposed projects included in this version of the Masterplan.


Operational capacity used in the market and network simulation might differ from the nominal capacities reported in the table above. Operational values are fully detailed in Chapter 4, in the description of each project.

Of the proposed 19 projects, only Spain - Morocco (P2), Italy - Tunisia (P4) and Israel - Cyprus - Greece (P12) are currently under development and are expected to come into operation by 2030. As such, these projects have been assessed using a Take One Out at a Time (TOOT) approach with respect to a 2030 reference grid. All other projects have been assessed using a Put IN one at a Time (PINT) approach.


Scenario building provides Med-TSO members with a common framework to verify - from a quantitative perspective and at a pan-Mediterranean level - national assumptions related to the evolution of lead and generation fleet, for each of the Med-TSO 2030 scenarios. Considering the weather-dependent nature of renewable energy and the various different operating conditions related to load and generation fleet, market studies are designed in accordance with a probabilistic approach, focusing on the weather condition impacts (wind, temperature, insulation, etc.) and using available weather databases.

Market simulations consist of an economic optimization of the overall generation cost of the full Euro-Mediterranean Power System, including commercial exchanges between bidding zones. The physical network is considered only to compute interconnection exchange capacities and minor internal constraints, where relevant.

The market simulator used is ANTARES, a sequential 'Monte-Carlo' multi-area simulator developed by RTE, the French TSO, and whose purpose is to assess generation adequacy problems and economic efficiency issues. The implementation of a market model makes it possible to obtain global and detailed visibility on the behaviour of the Mediterranean Power System for each of the scenarios through a large set of indicators and physical quantities, at hourly granularity. Output data include but are not limited to: power and energy produced by each type of generation plant for each country, border exchanges, marginal production price, national balance, unsupplied energy expectation, RES curtailment, and CO₂ emissions.

The methodology used for the cost-benefit assessment (CBA) has been developed to evaluate the benefits and costs of new interconnection projects, providing useful data and indicators for their assessment. The main objective of the CBA methodology used for this Masterplan is to provide a common and uniform basis for the assessment of these projects.

The following set of common indicators forms a complete and solid basis for project assessment across the Mediterranean area within the scope of the Mediterranean Project. The multi-criteria approach highlights the key aspects, pros and cons of each project, and provides sufficient information for decision-making processes. Applied indicators are summarized in the figure below and subsequently described.



B1. Socio-economic welfare (SEW) or market integration is characterized by a project's ability to reduce the occurrence of congestion between bidding zones. It provides an increase in transmission capacity that enables an increase in commercial exchanges, so that electricity markets can trade power in a more economically efficient manner. The SEW represents the money saved annually by the system thanks to the assessed project, including fuel cost savings and CO₂ emission variation monetization, as well as the monetization of the expected energy not supplied (EENS) variation. However, it is highlighted that the SEW ignores the grid losses variation, which are assessed through a different indicator.

B2. Variation in CO₂ emissions is the characterization of the evolution of CO₂ emissions in the power system due to the new project. It is a consequence of B1 and B3 (that unlocks generation with lower carbon content). Although this indicator is economically accounted for in the calculation of SEW (a variation of the CO₂ emission and the resulting change in emission costs that will affect the system costs), the CO₂ indicator is one key target in the Mediterranean Region and is therefore displayed separately.

B3. RES integration: Support to RES integration is defined as the ability of the system to allow the connection of new RES plants and unlock existing and future "green" generation, while minimizing curtailments. Although this indicator is economically accounted for in the calculation of SEW (a variation of the RES integration will result in a variation of the energy from conventional sources and thus affect the system costs.), the RES integration is one key target in the Mediterranean Region and is therefore displayed separately.

B5. Variation in losses in the transmission grid is the characterization of the evolution of energy losses in the power system due to the new project. It is an indicator of energy efficiency. The monetization of the grid losses considers the hourly marginal electricity price provided by the market studies, as further detailed in the associated section in the Network Studies chapter.

B6. Security of supply: Adequacy in meeting demand characterizes the project's impact on the ability of a power system to provide an adequate supply of electricity to meet demand over an extended period. Variability of weather conditions affecting demand and renewable energy sources production is duly considered. The monetization of B6 is performed through the value of lost load (VOLL), which is set to €3000/MWh. The assessment of the SEW assumes that the peak generation capacity is adjusted for maintaining the adequacy criteria - loss of load expectation (LOLE), below three hours in every Mediterranean country.

Sector coupling
The modelling link between electricity and hydrogen systems through electrolyzers creates a sector coupling. Electrolyzers are supplied by RES and/or nuclear electricity surplus to produce low-carbon hydrogen from electricity. Consequently, the development of new interconnections may affect the way the electrolyzers would be operated. In a schematic two-country configuration, the increase in electricity export capacities reduces the RES curtailment period in the exporting country and adds carbon-free electricity in the importing country. Depending on the country in which the electrolyzers are located, the impact of new electrical interconnections could result in a decrease or an increase in the low-carbon hydrogen production.

The calculation of the B1 indicator must therefore take these mechanisms into account to complete the total value of the SEW. The detailed modelling and calculation method is described in Chapter 2.6.2 of the ENTSO-E document entitled Implementation Guidelines for TYNDP 2022 based on 3rd ENTSO-E Guidelines for Cost benefit Analysis of Grid Development projects (Implementation Guidelines for TYNDP 2022 based on 3rd ENTSO-E Guidelines for Cost benefit Analysis of Grid Development projects).

CBA reporting
The calculation of B1, B2, B3 and B6 indicators is carried out for 35 climatic years and the Mediterranean Masterplan proposes the average value as well as the minimum and maximum values for each project. The geographical scope for calculating those indicators not only covers the Mediterranean countries but the entire interconnected Euro-Mediterranean electricity system.

Indicator B5, Grid losses, is calculated with data corresponding to the 1990 climatic year only, the year which presents the closest resemblance to the average value of the 35 climatic years in terms of annual exchanges on the Mediterranean interconnections. The set of indicators is presented for two scenarios: the Inertial scenario and the Proactive scenario.

Indicator B5, Grid losses, is calculated with data corresponding to the 1990 climatic year only, the year which presents the closest resemblance to the average value of the 35 climatic years in terms of annual exchanges on the Mediterranean interconnections. The set of indicators is presented for two scenarios: the Inertial scenario and the Proactive scenario.


While market simulations are used to calculate the benefits of interconnection projects, network analyses are needed to assess their impact on the transmission network and identify the required internal reinforcement for a secure system operation. Once the reinforcements have been identified and implemented, the same type of network simulations are used to calculate the variation of network losses associated with the analyzed project.

In TEASIMED, analyses have been based on an innovative Continuous Load-Flow approach. With respect to more traditional Mediterranean methodologies based on a set of representative Points in Time (PiT), the approach is based on AC hourly load-flow simulation for a full climatic year, as fully described in the following section.


Network studies are needed to verify the physical capability of a given power system to transport electricity in line with the outcomes of market studies while respecting quality and security standards. Running network simulations therefore allows us to:

• Evaluate the performance of the interconnected Mediterranean network by assessing its ability to transfer the bulk power flows resulting from the economic studies while ensuring the secure operation of the system.
• Identify potential criticalities related to the interconnections and the internal grids, in terms, for instance, of bottlenecks and voltage issues.
• Assess the need for internal reinforcements due to the new interconnections.

Network studies mainly involve load flow analyses, which compute the power flows and the bus voltages in an assigned electric system subject to the regulating capability of generators, reactive power sources, and on load tap-changer transformers in different operating conditions and according to specific security criteria.


A parallel can be made with water flow in a meshed pipelines with different inflow (generators) and outflow (load), a load flow describes how the water flow is distributed in the pipeline, helping to detect any problems in water distribution (e.g., overloads).

Load flow output is essential for the evaluation of the performance and security of a power system. Load flow analyses typically require the assessment of several cases in both normal and emergency operating conditions. Considering that the network includes a certain number of lines and transformers, N, N-1, and N-2 criteria are defined to verify the ability of the system to operate even with the lack of one element (N-1) or two elements (N-2).

Such ability may depend on the specific system and the faulty elements. The figure below shows a simplistic example of how two different systems may become unstable without one or two elements or may remain stable depending on the elements selected and their spatial distribution. Similar behaviour can be observed in an electric network where the lack of one element can be easily compensated in a well-meshed network while it is not sustainable in weaker parts of the system.




A description of the security criteria includes:

• The acceptable voltage range in normal and contingency situations (i.e., ±5% in normal and ±10% in contingency or in general for generation buses).
• The threshold for admissible overloads of network elements (i.e., 20% for lines, 5-10% for transformers).
• Contingency criteria (N-1, identification of N-2, loss of a substation, remedial actions).

The continuous load flow approach involves the assessment of grid conditions over a full climatic year, for a total of s8760 cases. As shown in the following diagram, the inputs for the calculation module include the market simulation results, the network models, and a set of security criteria needed to define dispatching conditions and verify grid quality standards to run 8760 load flows. Resulting contingencies are automatically analyzed to identify recurrent issues and select a set of most critical cases that require further investigation. The result of the investigation leads to the definition of transmission grid reinforcements needed for a secure operation of the electricity network including the assessed interconnection. Continuous load flow process is depicted in Figure 10.



Dispatching conditions for power generation are determined through merit order ranking data, as provided by TSOs for each country. The merit order is used to distribute the generation resulting from market simulations for each cluster (CCGT, OCGT, wind, PV, etc., in line with ENTSO-E's classification) among power generation plants belonging to the same cluster and included in the network model. To reflect the typical operation of the electricity network as closely as possible, several power generation criteria are considered, as displayed in the diagram below (Figure 11).


For demand, there is no notion of merit order. Demand is therefore dispatched only by differentiating fixed and scalable loads.

With respect to PiT-based methodologies, the applied continuous load flow approach assesses a wider number of grid conditions, theoretically allowing a more accurate and detailed identification of contingencies for further investigation. It also facilitates statistical analysis while delivering transparency on data calculated at each step. On the downside, the approach does not involve re-dispatching operations and does not allow sensitivity analysis on specific cases, as it relies on a fixed power generation merit order provided by TSOs.

Since the continuous load flow approach leads to a much higher number of cases to be assessed than a dedicated methodology, it has been put in place to select only the relevant cases resulting in contingency with high probability of occurrence and high impact on the transmission network. To limit simulation time, contingencies have only been performed on the cases perceived to be most critical for each country (between 1% and 5% of the total 8736 N situations). Based on these simulations, discussions have been held with each TSO to define optimal upgrades on networks to limit technical violations.

To select critical cases, each situation has been scored between 0pts and 5pts by applying the following criteria:

• +1pts for cases with highest average line loadings
• +1pts for cases with highest average transformer loadings
• +1pts for cases with lowest bus voltages
• +1pts for cases with highest bus voltages
• +1pts for cases for highest shunt reactor loadings

All situations with the highest scores have been selected. In addition, all cases with violations in an N situation were automatically selected for the N-1 study.

The following figure summarizes the selection of all situations simulated for N-1 studies.


In some cases, application of this methodology leads to many violations. To enable fruitful discussions with TSOs on possible reinforcements to solve such violations, these have been ranked based on:

• The rate of the element
• The occurrence rate of a Contingency/Violation pair
• The average violation value
• The maximum violation value

In order to evaluate the severity of a Contingency/Violation, a final indicator, or score (“γ”), has been defined, by combining all the aforementioned indicators. It has been designed to be a value without a unit and standardized to remain coherent between countries with different network sizes.

For each country, this score then enabled evaluation of the impact on either the contingencies or the violations by adding up the values as displayed in the table below. Furthermore, in accordance with each TSO, a threshold value has been defined in order to include only the elements that have a significant enough impact for the analysis.



The final step of the network simulations is to compute the variation and monetization of a network’s technical losses.

For each project, this is conducted for the reference grid and includes the assessed project and the associated identified reinforcements. Grid losses are calculated directly as part of load-flow simulations for the two conditions, as the difference between the total generation and the total demand in a country. For underwater cables, losses are attributed equally to the countries involved.

Monetization is then performed considering the marginal price of each market node obtained from market simulations that include the assessed project. The reference equation is the following:

Where Px is the assessed project

This approach has the benefit of allowing the assessment of losses on an hourly basis for all 8760 hours of the year.

However, considering that continuous load-flow approach does not involve re-dispatching and relies on fixed power generation merit order information provided by TSOs, calculated losses might not fully reflect the behaviour of network operation throughout the whole year. This phenomenon is, however, mitigated by the overall monetization approach, which only looks at the variation of losses resulting from the assessed interconnection.


The planning of an electrical transmission system can involve financial choices from among different technically feasible solutions. Making such choices requires the quantification of costs of the various system components.

The main components to be considered are transmission lines, transformer substations and conversion stations in the case of HVDC transmission. Additional components might be involved in the case of specific identified reinforcements.

Costs for the design, construction and installation of components have been collected directly from Med-TSO members. When not available, standard costs or costs used in similar projects have been considered. For the scope of this Masterplan, the equivalence between euros and USD has been established (€1 = $1).