Comment: 18 pages, 13 figuresIn 2021, the European Commission has adopted the Fit-for-55 policy package, legally binding European countries to reduce their CO2 emissions by 55% with respect to 1990, a first step to achieve carbon neutrality in 2050. In this context, it is crucial to help national policymakers to choose the most appropriate technologies to achieve these goals and energy system modelling can be a valuable tool. This article presents a model of the Italian power system realized employing the open energy modelling framework Oemof. A Linear Programming Optimization is implemented to evaluate how to minimise system costs at decreasing CO2 emissions in 2030. The developed tool is applied to evaluate different research questions: i) pathway towards full decarbonization and power self-sufficiency of the electricity sector in Italy, ii) relevance of flexibility assets in power grids: li-ion batteries, hydrogen storage and transmission lines reinforcement. A 55% CO2 emissions reduction for the actual Italian power sector can be achieved through an increase of 30% of the total annual system cost. Full decarbonization can be reached with four times today's annual costs, which could be lowered with sector coupling and considering more technologies.