If you are private, apartment block and a non-commercial entity, which use the service of net metering solely for their own utilities and their plants do not exceed of 20 kW of power, the contribution of exchange is not subject to VAT, and it is not relevant for Irpef.
If the plant is greater than 20 kW, for this category, energy put is considered a disposal for a commercial activity (sale of energy) and the contribution for the exchange will be a relevant amount for the VAT and for direct taxation, and an invoice will be issued to the GSE.
For the business activities which have implants of all sizes with net metering regime, the contribution for the exchange is a relevant amount both for the direct taxation and for the VAT, and the user will issue an invoice to the GSE.
For the purchase or the realization of the implant the subsidised VAT rate of 10%. The cost of the implant is depreciable according to the ordinary proceeding depreciation of capital goods, with a coefficient of 9% per year. If the implant is solely used for their own utilities/activities (indirect self-consumption) in a “net metering” regime, the contribution of the exchange represents a relevant amount both for the VAT and for the direct taxation, and the user will issue the invoice to the GSE. If instead the energy is given to the net and it is partially or completely sold (to the GSE or to the free market), it entirely contributes to the determination of the entrepreneurial income, as well as the incentive tariff of the Energy Bill. This is independent on the destination of the photovoltaic energy produced. Therefore, the energy which is sold is subject to VAT and determines the tax base according to IRAP and IRES. Revenues from energy sale are subject to withholding tax of 4% by the GSE.
The Fourth Energy Bill includes several bonuses, which are not cumulative, for specific kinds and application of photovoltaic plants. By simply considering the new things than the previous Energy Bill, the new Bill foresees a fixed premium of 0,05 € per kWh of produced energy in case of photovoltaic plants on buildings (excluded the ones with innovative features>) which replace the relative coverings in eternit or materials containing asbestos (art. 14, paragraph 1-c). Besides, a bonus of 10% has been introduced (art. 14, paragraph 1-d) on the incentives for installations which present an investment cost -excluded the part of the work-related for at least 60% to a production made in the European Union (EU). Since the 2013, the tariff to which the increase is applied is equal to the merely incentive. Anyway, the bonus is recognized on the whole electricity produced by the photovoltaic plant, regardless its use.