A framework for integrity assessment of multiscale energy infrastructures

The climate change phenomena represent a global issue that could significantly impact on world economic and social systems. During last decades, several international bodies and institutions (like the IPCC) developed scientific techniques to analyse the causes and effects of these phenomena, their evolution over time and possible future scenarios. According to these studies, in order to face climate change and air pollutant emissions issues several targets have been hypothesized and proposed. In particular, the ones related to the Paris Agreement (COP21) can be mentioned. These goals require, in the mid/long-term, significant changes in the structure of the energy systems at global level, aiming at achieving their substantial decarbonisation through the so-called “energy transition”. The implementation of this transition could be obtained by means of different pathways. In particular, two extreme options can be identified. On one side, a wide electrification of final uses, coupled with power generation from renewables and long-distance transmission through global interconnections. On the other, small-scale energy systems based on electricity, heat and gas produced by renewables sources, characterized by power generation from wind, solar photovoltaic and small hydro and with a relevant role played by storage systems. It can be expected that the future configuration of the global energy systems will be a mix of these extreme solutions. In every case, however, a crucial role will be played by the infrastructures for supplying, transmitting and distributing energy. For this reason, the integrity of these infrastructures – at all spatial levels (transnational gas and oil pipelines, maritime routes, power lines, district heating networks, etc.) – is a key factor for ensuring the long-term energy transition strategies. The integrity measures the capability of a given infrastructure to perform its function according to what is requested and to be properly managed from several points of view, including safety, environmental protection, maintainability, productivity, etc. Therefore, it is a concept more general than “security”, as it is multi-dimensional. Furthermore, the integrity is directly related to the development of infrastructures. The evolution of the current energy systems in the sense of the energy transition needs to plan the infrastructures architecture according to criteria that have to be not only technological, but also able to consider all the possible issues that can threat their integrity. In a long-term perspective, these issues should not be investigated through ex-post analyses, but they should be taken into account as much as possible in the design phase. Starting from this, the main goal of the doctoral project has been the identification of a multiscale approach for assessing the integrity of energy infrastructures. A two-dimensional scheme has been proposed, considering different spatial scales (energy corridors, transmission/distribution infrastructures, local networks) and kind of threats (natural, accidental, intentional) and assessing the impacts on the integrity dimensions (technological, geopolitical, environmental, economic) In particular, five case studies have been considered, covering all the considered spatial scales with respect to different integrity dimensions and threats. They focused on the geopolitical supply security, the resilience of distribution infrastructures, the effects of renewables penetration, the reliability of district heating networks and the impact of innovative vectors on the security. The obtained results showed that this multidimensional approach can be useful in defining guidelines for the integrity assessment and the development of energy infrastructure under a holistic perspective, in order to support the policy decision-making about strategical investments and their prioritization, planning, management, and identification and ranking of criticalities.