Worldwide diffusion of solar photovoltaic panels and the role of state incentive: perspectives based on diffusion models

The main goal of this thesis is to use the diffusion models to improve ourunderstanding of SPP markets, with special focus on (a) identifying the maindeterminants of the diffusion of solar photovoltaic panels worldwide,particularly the role played so far by public incentives, (b) characterising thescale and temporal profiles of the major domestic shocks in SPP markets whichmostly occurred after 2007, (c) discussing the resulting perspectives, and theinvolved role of public policies, for the future development of the market.Chapter 1 is introductory and preparatory for subsequent ones and pinpointsthat (a) the presence of shocks is an intrinsic and often dominating feature ofenergy markets, thereby motivating the use of tools as the GBM, (b) only a fewcountries have developed long-term energy plans towards which to manageconsistently their short-medium term policies, (c) the concept of energyframework was useful to indicated a number of commonalities amongcountries.The main findings of Chapter 2 were the following: i) essentially everywherethe effectiveness of media communication proved negligible, ii) the early phasewhere the growth of the market was completely sustained by internalcommunication only, iii) major changes in the market adoption curves haveoccurred in the form of massive positive shocks which took place between 2006and 2016 possibly following incentive measures in the various states, iv)inspection of the parameter estimates describing the temporal pattern of theshocks showed a lack of temporal persistence of the effects of incentive as wellas a sharp trade-off between intensity and persistence of the actions.The results of Chapter 3 show that the SPP residential market in UK suffers notonly the structural difficulties of this sector, but also the possible perception ofrelative penalisation suffered by late cohorts of adopters compared to the pastcohorts who benefited higher rates of FIT. In the commercial and utility sectorsthe imitation rate is higher which might be explained by the fact that firmsmake more rational decisions based on economic factors rather than being ledby perceptions.