A Methodology for Assessing Environmental Benefits from LNG Transition: The Case of Regione Sardegna

The use of Liquefied Natural Gas (LNG) is crucial for reaching the pollution reduction objectives that have been set by the new European laws. The widespread use of LNG allows for the reduction of air-polluting emissions in many fields, from residential to industrial and transport sectors. The European Project SIGNAL is aimed towards supporting and bolstering the diffusion of LNG usage, especially in port areas and in regions that are not connected to the main continental NG network (e.g. islands or border regions) where LNG is still a convenient alternative to the construction of distribution infrastructures. Considering that the impact of primary LNG consumption is strongly affected by the efficiency of technologies employed in energy conversion, it differs from sector to sector and from country to country. For this reason, it is useful to evaluate the environmental benefits deriving from the conversion to LNG fed technologies, to assess the effective emission reductions. In the present paper, a simple yet fast and reliable methodology to assess the environmental benefits is presented. The methodology is relying on the application of the Emission Factors available on the Emission Factor Database developed by the European Union, integrated with other national databases or literature studies, in case of lacking data. Moreover, in the present paper, the case study of Regione Sardegna is presented. Starting from the regional energy needs, it is possible to evaluate the current emissions levels amount for five selected pollutants (PM 2.5, PM10, CO, CO2, NOx, SOx). Then, two different scenarios are forecasted, with a 10-year timespan: a low LNG widespread and a high penetration one. Then, the emission levels for the two cases are evaluated and compared to the base case. Overall, the use of LNG is helpful towards the reduction of air emissions, especially for PM2.5, PM10, and SOx. The emissions for CO and NOx can anyway increase up to 5.5% when a single sector is analyzed, depending on the level of technology development of the considered sector.