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Abstract:Power Grids face significant variability in their operation, especially where there are high proportions of non-programmable renewable energy sources constituting the electricity mix. An accurate and up-to-date knowledge of operational data is essential to guaranteeing the optimal management of the network, and this aspect will be even more crucial for the full deployment of Smart Grids. This work presents a data analysis of the electricity production at the country level, by considering some performance indicators based on primary energy consumption, the share of renewable energy sources, and CO 2 emissions. The results show a significant variability of the indicators, highlighting the need of an accurate knowledge of operational parameters as a support for future Smart Grid management algorithms based on multi-objective optimization of power generation. The renewable share of electricity production has a positive impact, both on the primary energy factor and on the CO 2 emission factor. However, a strong increase of the renewable share requires that the supply/demand mismatching issues be dealt with through appropriate measures.

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h i g h l i g h t sTitanium tetrachloride is proposed as new fluid in high temperature Rankine cycles. We show experimentally that it is remarkably stable at temperatures up to 500°C. Resulting plant efficiencies of 35-40% are higher than state-of-the-art ORCs. Its high reactivity with water poses some concerns in the design of a power plant. a r t i c l e i n f o b s t r a c tIn this paper, Titanium tetrachloride (TiCl 4 ) is analyzed/assessed and proposed as a new potential working fluid in Rankine Cycles. Besides its good thermodynamic properties, TiCl 4 is in fact a fairly low cost, non-carcinogenic fluid, with zero Global Warming Potential (GWP) and Ozone Depleting Potential (ODP) and it is currently employed in high temperature industrial processes. It is however very reactive with humid air and water. A preliminary thermodynamic analysis confirms its possible application in power plants with maximum temperature up to 500°C, considerably higher than the ORC state-of-the-art technology, performing electrical efficiencies as high as 35-40%. This suggests the potential use of TiCl 4 as an alternative fluid in ORCs allowing the exploitation of high temperature sources (up to 500°C), typically used in steam cycles. To assess the possibility of operating the cycle in such high temperature conditions, we carried out an experimental thermal stress analysis, showing that the fluid is remarkably stable at temperatures up to 500°C, even in presence of P91 and Cupronickel, two materials typically employed in the high temperature section of power cycles.