Worldwide Transition to Solar and Wind Technologies. Analysis and Perspectives on Current Trends.

As the carbon budget dramatically approaches depletion, solar and wind energy sources are cementing their role in the current energy transition, emerging as the most technologically mature and competitive alternatives for rapid decarbonization. Despite signs of sustained growth in renewable energy additions, coal and natural gas, long-standing cornerstones of electricity production, do not show clear evidence of recession on the global scale. This persistent dependence on fossil fuels is deeply rooted in the complex social, political, technological, and economic interdependencies that have shaped modern society, creating a spiral of inertia and path dependency. However, when examined at a broader level, this complexity reveals itself as part of a larger and more predictable system, where aggregate energy technology trajectories follow highly regularized patterns. In light of these fascinating regularities, innovation diffusion models are used to capture the current perspectives of solar and wind energy technologies, with a specific focus on measuring their competition strength in curbing new fossil fuel additions. Building on the conceptual foundations laid during the Ph.D., this thesis investigates the energy transition process in 75 countries, analyzing, retracing, and generating model-based mid- to long-term prospects for 50 national energy markets. The time-to-parity, as a key indicator to monitor transitional effort, is conceptualized and estimated. The results indicate that only a limited number of regions have managed to outline a sustained transition path, returning an alarming perspective on the current status of international support and cooperation toward climate change. The final chapter of this thesis provides a specific focus on the Italian market aiming to update, amend, and deepen the results published in my previous coauthored work entitled Diffusion of Solar PV Energy in Italy: Can Large-Scale PV Installations Trigger the Next Growth Phase?, published in Energies journal. Specifically, the chapter estimates the final absorption time of the key incentive system for residential adoption, the Super Eco-Bonus 110%, by the end of 2026, indicating a likely return to inertia for new small-scale solar photovoltaic installations. In addition, the study offers a new assessment of the adoption pattern of industrial-scale projects, whose trend has begun to sharply diverge from the previously aligned trajectory with the utility-scale market.