Meeting the targets of climate change mitigation set by the Paris Agreement entails a huge transformation of the energy sector, as low- or no-carbon technologies are predicted to gradually substitute traditional, fossil-based technologies. From a technology perspective, power generation is at the same time the largest responsible for CO2 emissions and the most promising sector for decarbonization, therefore great mitigation efforts are expected in this area. From a policy perspective, it is common opinion that the European Union is and will remain global leader in implementing clean policies, such as the Energy Roadmap 2050, which aims at cutting greenhouse gas emissions by at least 80% within the first half of the century with respect to 1990.

The power sector and the European Union have thus been chosen as the key actors of the MERCURY project – Modeling the European power sector evolution: low-carbon generation technologies (renewables, CCS, nuclear), the electric infrastructure and their role in the EU leadership in climate policy ( The main tool adopted in the project is the Integrated Assessment Model (IAM) WITCH (

This seminar focuses on the prospects – in Europe and on a global level – of the three main low-carbon power technologies: renewables (in particular, solar PV), CCS (Carbon Capture & Storage), and nuclear. The first part describes a multi-model comparison involving four IAMs and led by WITCH having a twofold objective: i) explore different PV capital cost pathways deriving from different assumptions on endogenous learning-by-doing, and ii) assess the impacts that these low cost pathways have on the penetration of PV and Variable Renewable Energies (VREs) in the electricity mix. The second part, inspired by the several issues that still hinder CCS commercial development, investigates the impacts of a progressively delayed deployment of this technology from a climate, energy, and economic point of view. The third part discusses the nuclear expansion that many models project in carbon mitigation scenarios in the light of the critical prospects that this technology actually faces, especially in the Western world, for instance considering the reactors ageing and the phase-out plans that many countries have been implementing.