Rendita catastale e “rendita solare” degli impianti di produzione elettrica a fonti rinnovabili: perequazione fiscale energetico-immobiliare

Among the topics addressed by the Law of 11 March 2014 n. 23, delegating to the government for a fairer tax system, there are two fundamental issues which are the subject of this study, the cadastral reform and the energy and environmental taxation. The new reform of the cadastre of buildings aspires to achieve a more equalized tax system by removing the disparity between cadastral incomes (and assessable values) and incomes (and property values) observable in real estate markets. The Law n. 23/2014 also introduces the necessity of defining an energy-environmental taxation in order to promote the growth of green economy. The definition of an energy and environmental taxation is very broad issue. It includes many aspects related to the activities of production and consumption. However, with regard to the development of the electric energy market from renewable sources, it is referable to the theme of greater correspondence between cadastral incomes and values and respective incomes and values in actual market. The disparity in the definition of cadastral incomes and values affects the whole system of taxation that comes from them. It is the whole system of real estate taxation, including on property taxes or taxes on other real rights on real estate, the taxes due in the sale and transfer by gift or inheritance of properties and also the income tax of individuals. For the resulting consequences on the tax system, the gap between real estate market values and cadastral values have aroused great interest of appraisal scholars, that agree on the need for similarity of assessed values registered in the cadastre and values detectable on actual market. This condition must be satisfied in order to allow the cadastre to perform properly its own fiscal function. The cadastral estimation applied to buildings in ordinary destination generates inequalities arising in part from the macroscopic analysis of the built environment - which set aside an accurate segmentation of the housing market - and in part by the application of the estimation procedure "for classes and rates", in which the linking scales of real estate earnings and the linking scale of municipalities allow us to attribute to individual real estate units the relative rates of cadastral estimation. These apply to consistencies of the surface obtained, in their turn, with automatic coefficients for the conversion of the cadastral rooms. Issues of tax equity similar to those that the delegating law wants to address through the reform of the cadastre of buildings belonging to ordinary cadastral categories (A, B and C) emerge also in relation to real estate immovable for special purposes and for lands. For what concerns power plants using renewable energy sources, the theme of the lack of fairness in taxation for real estate properties for special purpose is of great importance for supporting the development of green economy in Italy. The present contribution deals with the theme of equity in attribution of cadastral incomes to installations for the production of electric energy using alternative sources scattered on the land (solar irradiation and wind power). A remedy for reducing inequality of incomes attributed according to current cadastral praxis is proposed. In Italy, the electricity production market from renewable sources was still negligible at the end of the nineties. Following the impetus provided by incentive policies adopted since 2001, the program "Photovoltaic roofs" and the five subsequent versions of the so-called "Energy Account", it has developed rapidly in the fields of photovoltaic and wind power. With the National Action Plan for Renewable Energy (PAN) and the recent National Energy Strategy (SEN), developed in the context of energy and environmental policies promoted by the Euro-pean Union, Italy has made specific commitments on development of use of renewable energy sources and on the reduction of the production of greenhouse gases. These commitments require, among other things, a new increase in the produc-tion of electric energy by technologies free from production of greenhouse gases. Therefore, the issue of fairness in the attribution of cadastral income to installations producing electric energy by renewable sources, already involving a large number of plants, will affect in the short to medium term a growing number of installations, and most importantly, a significantly higher in-stalled power, with considerable effects on tax revenues resulting from the tax base of cadastral nature. In general, the photovoltaic and wind power plants belong to the cadastral category "D/1 - factories", unless they have a modest power and are in-tended for self-consumption or are classifiable in the category "D/10" of "factory buildings for the production functions related to agricultural activities". Operational difficulties related to the lack of active markets for lease and sale of property units intended for special and particular use are found more so in the still latent market for solar and wind power installations. This circumstance makes it inapplicable, in cadastral praxis, the direct estimation procedure of the cadastral income for derivation from the gross average annual lease fee. A similar difficulty arises in the application of the indirect estimating method of the cadastral income derived from the capital value. Therefore, the cadastral praxis commonly resorts to the indirect process deriving income from the capital value expressed by the value of the reconstruction cost. Therefore, the annual income of wind and photovoltaic power plants surveyed in the cadastral category D/1 is determined by multiplying the reconstruction cost of the installation by an appropriate fruitfulness rate. Based on the in-dications of the prevailing case law, the latter is assumed to be equal to 2%, as for the other categories of the Group D. On the basis of the cadastral practice, the cadastral income of photovoltaic or wind power installations of similar antiquity is the same for all the ge-ographical locations, without considering the value of the land on which they are installed and of any other possible manufactures belonging to the real estate unit. This assessment does not reflect the real capacity of the plant to produce income through the sale of the produced energy. Even in the case of plants for the production of electric energy using renewable sources, the cadastral income is undocked from the actual values. From it is derived arbitrary taxable income with respect to actually received income. In fact, the different geo-climatic areas are characterized by different “local solar energy potential", of the direct type, in the case of solar radiation that activates the photovoltaic production of energy, or of the indirect type, in the case of the wind power that activates the blades of wind turbines. The abandonment of the static system of rates of return - crystallized for the different cadastral categories by established case law - would allow, even in this special real estate category, to ex-press a correct relationship between incomes and capital values. Alternatively, the adoption of corrective coefficients for increase or reduction in the values of cadastral income of installation for the production of electric energy using renewable sources relative to areas with central values in the range of the "solar potential", could allow you to integrate the cadastral estimation, with a minimum computational commitment, the different local direct (radiation) or indirect (wind) solar potential. The income deriving from the production and sale of energy produced by the plant depends, in general, on many factors that determine - on an equal footing of installed nominal power, of geo-climatic location and of position of the modules in the space (tilt and orientation) - the amount before the effects of the specific tax regime to which the plant owner is subjected to. In any case, the said income is descended from an original factor identifiable in the level of aver-age annual solar radiation that affects the territorial location of the installation. In particular, the Italian territory has global annual mean values of solar radiation from about 1100 to about 1800 kWh/sq m, with maximum variation of 24% compared to the central value. This distribution in the value of solar radiation generates a variable amount of production of electric energy per unit of installed power between a minimum of about 900 and a maximum of 1500 kWh/kWp, in correspondence with an optimal arrangement of modules. Therefore, it is proposed an appropriate system of corrective coefficients, able to contain the disparities between the cadastral incomes attributed to installations allocated in sites characterized by productive potentiality gaps that, in the maximum case, can reach the extent of about 50%. The correction factors allow better commeasure cadastral incomes and actual "solar incomes", reducing the disparity of the tax system. The proposed procedure applies, in a similar manner, to wind power plants, by introducing a number of classes of merit relative to the range of wind conditions found throughout the country, considering the case of on-shore and off-shore installations. The adoption of the proposed evaluation model could be a first step towards the construction of a system of cadastral incomes related to power plants by renewable energy sources closer to the real system of "rents from local energy potential". In fact, the "solar income" descends from the local geo-climatic characteristics, both of macro-climatic type and of micro-climatic type. The use of geo-referenced information technology (GIS) in the specific field here considered would permit a more precise integration of solar yield differentials in a cadastral Geographic Information System up to date, efficient and equitable, adequate to the multiple functions that the cadastre is called on to perform. In order to attribute cadastral incomes to power plants using renewable energy sources consistent with the real macro and micro-climatic conditions of the installation site, it would be appropriate to establish a special "cadastre of solar annuities". It must be based on the information technology for the geo-referenced data and on the specific integrated tools that allow you to quickly obtain these values for individual land parcels or groups of them.

Fra i temi affrontati dalla legge 11 marzo 2011, n. 23, recante delega al governo per un sistema fiscale più equo, spiccano le questioni fondamentali della riforma catastale e della fiscalità energetico-ambientale, di cui si tratta nel presente studio. La nuova riforma del catasto dei fabbricati aspira a realizzare un sistema fiscale più perequato at-traverso la rimozione della disparità fra redditi (e valori) catastali e redditi (e valori) osservabili nei mercati immobiliari. Il tema catastale è rilevante per i molteplici effetti fiscali che ne derivano, e il divario esistente fra i valori di mercato e quelli catastali, hanno suscitato un grande interesse degli studiosi di estimo, stimolando la produzione di una mole di interventi di natura teorica, sulle finalità ed obiettivi del catasto, ed operativa, con sperimentazioni e proposte di procedimenti estimativi immobiliari professionali o appositamente concepiti per le applicazioni ca-tastali. Questi studi affrontato le tematiche suddette principalmente in rapporto agli immobili a destinazione ordinaria e ai fondi agricoli. Le problematiche di equità fiscale che la legge delega intende affrontare mediante la riforma del catasto dei fabbricati emergono, tuttavia, non soltanto nell’ambito delle categorie di immobili a destinazione ordinaria, ma altresì per gli immobili a destinazione speciale. Questo contributo approfondisce il tema in rapporto agli impianti per la produzione energetica da fonti alternative diffuse sul territorio (irraggiamento solare e vento). Il diverso “potenziale energetico locale” dei vari siti geografici, consente di rilevare una “rendita solare” differenziale che si concretizza in una variegata redditività di analoghi impianti a fonti rinnovabili diffuse installati su territori con localizzazione geografica differente. Alla luce di tale osservazione, si evidenziano i li-miti del procedimento adottato dal sistema normativo italiano e dalla prassi catastale per la stima della rendita catastale degli impianti a fonti rinnovabili e si proporre un rimedio coerente con gli obiettivi di incentivazione delle produzioni energetiche a più elevata qualità ambientale, da perseguire anche mediante un’adeguata fiscalità energetica, come prescrive l’art. 15 della legge delega in oggetto.