As a result of the Russia-Ukraine war, the global natural gas market has suffered from the last two years to present, a major imbalance. The dependence of some major European countries on natural gas is almost total (Germany has been cut off the North Stream 1-2 gas pipelines) and this makes us understand the concern of the stakeholders, of the policymakers but above all of the European citizens, especially the Italian ones. Before the start of the Russia-Ukraine war and until June 2022, Italy was 40% dependent on Russian gas, with an import rate that was stable in line with previous years. Since June 2022, Italian imports have dropped by an annualized value of 8 Gscm, going from 74 to 66, against a further drop in Russian supplies of around 4 [Gscm/y]. This has led to a series of imbalances both from an energy and an economic point of view with energy-intensive industries mainly dependent on gas, forced to decrease their production. Starting from the second half of the year 2022, the government has implemented a strategy of strong diversification of gas supply sources managing to organize a stable import network through pipelines from Azerbaijan, Algeria, northern Europe, Libya and through LNG tankers from the United States. However, the unstable geopolitical situation in which we find ourselves nowadays, places governments in front of the need to develop energy strategies capable of diversifying the sources of electricity production as much as possible, so as not to go into crisis if the main source fails.

In the Italian case, most of the electricity production comes from gas-fired thermoelectric plants, which means that situations similar to those that occurred with Russia in the summer of 2022, could recur in the future. The drop in Russian gas imports that occurred between May and June 2022 (about 11% less gas needed annually for Italian consumption) would be equivalent, in a scenario of a sudden drop in imports not supported by a diversified energy policy, to a lack of annual electricity calculated to be equal to approximately 17.33 TWh.

In this study, purely energy analyses were conducted - relating to two possible gas replacement scenarios following the closure of some Italian gas-fired power plants, caused by lack of gas supplies.

The first scenario, i.e. the complete repowering of the on-shore wind turbines added to the implementation of solar farms in the Italian SIN sites (National Interest Sites), manages to fill the predicted energy deficit. However, the uncertainty of renewable sources and problems of management of the electricity grid must be faced.

The second scenario, i.e. the reopening of coal-fired plants with the implementation of post-combustion carbon capture systems (CCS-PC) added to the conversion of existing coal-fired plants using CCS-PC technology, does not allow bridging the predicted energy gap. However, in the medium-long term, by adopting a policy of replacing gas-fired plants with coal-fired plants converted using CCS-PC technology, three advantages can be achieved simultaneously: i) significant reduction in emissions compared to natural gas-fired plants; ii) constant coverage of the base load; iii) better diversification of supply of primary energy sources.