At the specific request of the Italian Regulatory Authority for Energy, Networks and Environment (ARERA), independent external model-based checks have been launched on some selected interventions of Terna’s 2018 Development Plan (PdS 2018). With reference to the technical-economic assessments of the network reinforcements aimed at the Cost-Benefit Analyses (CBA), ARERA has requested a comparison between the calculations obtained using the RSE modeling tools and the conclusions drawn by Terna following its own calculations and models. The same hypotheses and the same input data have been used.

The activities carried out during 2019 have concerned the simulations of the Sustainable Transition scenario in a 2030 horizon (ST 2030) and aimed at analyzing the benefits relating to the reinforcement of the Sicilian very high voltage network, with particular focus on the 380 kV double circuit power lines “Chiaramonte Gulfi – Ciminna” and “Assoro – Sorgente 2 – Villafranca”.

The methodology adopted for the study is similar to that used by Terna as set out in the methodological document for the cost-benefit analysis attached to the PdS 2018. The reference calculation tools (REMARK and RUC) are part of those developed by RSE during the previous years of System Research to support the planning of the electricity transmission network.

Obtained with the application of the REMARK program in reference to the ST 2030 scenario, the results currently available are those relating to the benefits in terms of variation of network losses, variation of expected non-supplied energy, integration of production from renewable energy sources (RES), variation of costs for network services (resolution of network congestion).

In some cases, the results obtained regarding the Sicilian reinforcements have shown a certain consistency with those published in Terna’s PdS 2018. However, some aspects would require further study: the study hypotheses must be set with greater clarity and rigor because the validity of the results strongly depends on them. This point is crucial to guarantee analyses’ repeatability (also for future Development Plans) and detailed evaluation of the benefits’ variability when the scenario hypotheses and methodological aspects vary.

Therefore, the study only covered some of the expected benefits: in particular, the ones on the Dispatching Services Market (DSM) regarding reserve and balancing remain to be assessed. Furthermore, the entire analysis should be repeated for the Distributed Generation scenario in 2030 (DG 2030).