Before the end of this decade, PV systems will offer the opportunity for every European citizen to become a producer by exchanging electrical energy with the grid via its decentralized source. This exchange will occur at a competitive price once grid parity is achieved, but at present incentive systems are needed in order that the producer can have revenues. This paper shows that, in the framework of Conto Energia – the photovoltaic incentive system in Italy – the payback time of any photovoltaic plant is decreasing over time regardless of geographic location and in spite of the decrease of incentive rates. The paper considers dynamic irradiation models of the different places where the plant is built, inflation, energy costs, interest rates, construction costs and the different incentives for different investment and profit rate to analyze the payback time of investment in photovoltaic through all versions of Conto Energia.
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