From Photovoltaic to Agri-Natural-Voltaic (ANaV)

Abstract

Italy is the geographic area with the highest world concentration of cultural sites, landscapes with a high esthetic value, and biodiversity. Therefore, any modification in the territory is to be performed by highly considering these cultural, landscape, and natural values. Also, Italy has a high human pressure on agricultural areas, especially in flatlands, that generally have a high agronomic value. As a consequence, the planning of photovoltaic installations in agricultural areas must meet at least five basic criteria: to cause as little use as possible to the agricultural soil, to maintain agricultural activities, to strengthen or introduce natural habitats, to properly mitigate the landscape impact, and to be located as far as possible from residential areas. This chapter presents the technological innovation with a high environmental value that characterizes the photovoltaic system, called Agro-Natural-Voltaic (AnaV), also using methodological and planning schemes together with landscape simulations. Moreover, the essay gives a description of the study on the environmental impact (for the administrative procedure of the Environmental Impact Assessment), laid down for the emblematic case study.

1. Introduction

Italy is the geographic area with the highest world concentration of cultural sites, landscapes with very high aesthetical value, and biodiversity. It is also the country with the highest number (59) of sites on the UNESCO World Heritage List. In fact, new properties were added to the WHL: on 26 July 2021 “Padua’s fourteenth-century fresco cycles and Montecatini Terme,” and on 28 July the “porticoes of Bologna” and 8000 hectares of Italian forests within the transnational candidature “Primeval beech forests of the Carpathians and other Regions of Europe.” In this special ranking, China is second with 56 sites and Germany is third with 50 sites.

They are prevalently cultural sites, some of which with considerable natural and landscape importance.

Therefore, any modification in the territory is to be performed by highly considering these cultural, landscape, and natural values.

The great promotion of renewable energy (especially sun and wind) has led to a conflict in Italy between those who want to preserve the landscapes and those who want to transform them regardless of the characteristics of renewable energy projects, which very often produce a heavy bureaucratic blockage.

Before transforming a territory, the project of renewable energy must forcibly be environmentally compatible with the site concerned and not vice versa, and this is of crucial importance in the geographic case of Italy.

2. Photovoltaic

There are several types of photovoltaic projects [1], as synthetically presented in Table 1.

Table 1

Comparison between different types of photovoltaic projects.

Italy has greatly developed photovoltaic technology and, in this case, also its production modes. In particular, a different conceptual paradigm has been recently proposed: first, the environmental characteristics of a geographic area are studied, then, the kind of photovoltaic is defined.

The case study presented in this essay seems to be the most important “system technological innovation” that characterizes the planning of photovoltaic in Italy (as well as in all those geographic areas characterized by high environmental sensitivity).

Figure 1 summarizes the evaluation process realized for the photovoltaic project called “Agri-Natural-Voltaic (ANaV), proposed by Tozzi Green SpA located in Mezzano (Province of Ravenna) in Italy. The project was approved in 2022 by the National Committee of Environmental Impact Assessment of the Italian Ministry of Ecological Transition¹.

Figure 1.

Conceptual table: environmental feasibility and its relation with the environmental assessment.

3. The “Agri-natural-voltaic” technology (ANaV)

Considering the analysis of the different projects for the photovoltaic system [2], presented above, the ANaV project is compared to other projects with the same technology but with different uses of the soil (called Scenarios).

The comparison is carried out through a comparative table (Table 2) to better understand the characteristics of the different photovoltaic projects, which shows the best environmental sustainability of the innovation of the ANaV project.

	Scenario 1	Scenario 2	Scenario 3	Scenario 4 (ANaV)
	Type of system
Project characteristics	Fixed mount photovoltaic	Intensive agri-voltaic (single-axis trackers + super intensive olive growing system)	Diversified agri-voltaic (single-axis trackers + diversified agriculture)	Agri-natural-voltaic (ANaV) (single-axis trackers + diversified agriculture and renaturalization)
Usable agricultural area	10% Net of the ground surface occupied by the installation	30% Net of the ground surface occupied by the system	76.35% Including the sub-panel belts	89.32% Including the sub-panel belts and the green belts
Possible cultivations	Artificial grassing (non-natural, non-spontaneous species).; Working stages: 1. late spring/early summer—soil tillage, with mechanical weeding by agricultural tractors and inter-row milling machines to prevent fire risks related to spontaneous herbs drying up.; 2. winter—sowing with conventional agricultural machinery.; 3. early spring—grass shredding.	Field farming in spacings.; Setting up of a row on a central axis along a string line with a stake at the beginning and at the end of the row for good anchoring.; Non-cultivable areas: near the photovoltaic modules, with the max horizontal covering, artificial grassing (non-natural, non-spontaneous species) will be introduced.; Grass-cutting could be unnecessary since agricultural crops could help clean the areas under the panels with ecologic hot-water weeding.	Field farming in spacings; + lateral belts under the panel since the tilting movement enables land use for agricultural crops. The expected growing area is part of the existing biological agriculture and is organized in long-term (10 years) crop rotations.; Adoption of agricultural crops in line with local crops: artichoke; asparagus; crop rotation of cereals and legumes; honey plants; non-cultivable areas near the photovoltaic modules, in a row of about 1 m around the panel support poles.	Field farming in spacings; + lateral belts under the panel since the tilting movement enables land use for agricultural crops. The expected growing area is part of the existing biological agriculture and is organized in long-term (10 years) crop rotations.; Adoption of agricultural crops in line with local farming: artichoke; asparagus; crop rotation of cereals and legumes; honey plants; noncultivable areas near the photovoltaic modules, in a row of about 1 m around the support poles.
Description of renaturalization operations and relevant management	No renaturalization interventions to stop spontaneous colonization	No renaturalization interventions to stop spontaneous colonization	No renaturalization interventions to stop spontaneous colonization	A wide area on the lateral belts of the system is envisaged for the development of the surrounding natural habitats 6220, arid Mediterranean meadows. This is a semi-natural environment, residual with respect to previous agricultural use or coming from sparse grazing. Its realization does not only integrate the installation area with the surrounding environmental mosaic, but it also helps local biodiversity and grazing/beekeeping
Increase of biodiversity	Increase of fodder plant species, limited by the perennial shading of some belts caused by fixed panels	Increase of fodder plant species.; Partially limited by the perennial shading of some belts caused by fixed panels.	Increase because of crop diversification and fodder plant species.; Minimally limited by the perennial shading of some belts near the structure mount.	Increase of biodiversity that maximizes the integration between agricultural and naturalistic features.; Minimally limited by the perennial shading of some belts near the structure mounts. The agronomic module is part of a wider scenario integrated with the naturalistic part that is expected to use a wide surface on the lateral belts of the installation for the development of the area natural habitat (6220 – arid Mediterranean meadows)
Description of agricultural activities (use of chemicals, water consumption, etc.)	None	Installation of a system of drip irrigation.; Phytosanitary treatments with a pneumatic nozzle that channels water jets only on one side, and is trained by a tractor.	Since the land concerned is presently managed in a certified biological regime, also in the future the organic directives will be valid, and therefore special attention will be paid on the organization of crop rotations. Together with the non-use of active substances (fertilizers or pesticides), these represent one of the basic principles of agricultural sustainability.; Traditionally, irrigation is not planned (except in case of emergency and only for artichoke crops).	Since the land concerned is presently managed in the certified biological regime, also in the future organic directives will be followed, and therefore special attention will be paid on the organization of crop rotations. Together with the non-use of active substances (fertilizers and pesticides), these represent one of the basic principles of agricultural sustainability.; Traditionally, irrigation is not planned (except in case of emergency and only for artichoke crops).
Description of the project with reference to the landscape (structural reading)	Total, permanent, and standardizing modification of farmland, which is represented as a totally used productive area.	Partial and permanent modification of farm landscape, since part of the land is used for mechanized olive-growing.	Partial and dynamic modification of farm landscape, since free areas are cultivated in rotational crops.	Partial and dynamic modification of farm landscape, since free areas are cultivated in rotational crops.; In line with the landscape that characterizes this agricultural section, the project includes olive groves, orchards, and vineyards in the perimeter belts of the ANaV installation, following the patterns and crops existing across the Provincial Road SP 83 (“tratturello,” sheep track), and the olive groves of the agricultural landscape along the Provincial Road SP 95.
Description of the project with reference to the landscape (perceptive reading)	Total obstruction of the perceptive vision due to the type of the system	Total obstruction of the perceptive vision due partly to the installation and partly to super-intensive olive growing	Dynamic partial obstruction of the optical cones (longitudinal and orthogonal): longitudinal: limited optical obstruction since the panels do not interfere with the landscape. As regards the width of the optical cone, the view is open only with horizontal panels; orthogonal: variable according to the panel orientation	Dynamic partial obstruction of the optical cones (longitudinal and orthogonal): longitudinal: limited optical obstruction since the panels do not interfere with the landscape. As regards the width of the optical cone, the view is open only with horizontal panels; orthogonal: variable according to the panel orientation.; For consistently integrating with the landscape and reducing the view of the technological parts, the project envisages to introduce orchards, olive groves, and vineyards in the perimeter belts.
Farming profitability	Grass cover is not significantly profitable.	The super-intensive can dramatically reduce the need for labor, not only for harvesting operations (in the traditional system this means up to 80% of the total costs) but also for all the other mechanized operations such as pruning or the realization of the plantation. With the Super-Intensive System (SHD 2.0 SmartTree), it is possible to have a greatly improved profitability, especially thanks to a significant reduction of laborers.	Adoption of crops in line with local farming. Especially orchards produce a high remuneration per hectare (against high demands for labor); Supplementary income; Introduction of areas dedicated to the cultivation of melliferous plant species for the breeding of honey bees (Apis mellifera) hosted in hives positioned under the photovoltaic panels for ancillary honey production (Honey-Solar)	Adoption of crops in line with the local cultivations. Especially orchards produce a high remuneration per hectare (with high demands for labor).; Supplementary income.; Introduction of areas dedicated to the cultivation of melliferous plant species for the breeding of honey bees (A. mellifera), hosted in hives positioned under the photovoltaic panels for ancillary honey production (Honey-Solar)
Integration with local agricultural production	None	Olive growing and the production of olive oil are typical of the project scope. This is a greatly developed agricultural sector in the agro-food district of Cerignola.	Existing local chain supplies for horticultural crops (agro-food district of Cerignola) and cereal crops (large-scale cultivation of durum wheat for pasta production in the area of Foggia)	Existing local chain supplies for horticultural crops (agro-food district of Cerignola) and cereal crops (large-scale cultivation of durum wheat for pasta production in the area of Foggia)
Employment	Total loss of jobs in the agricultural sector.	High loss of jobs in agriculture because of a high level of mechanization.	The adoption of crops chosen in line with local crops does not cause disturbances to the local market, including the labor market	The adoption of crops chosen in line with local crops does not cause disturbances to the local market, including the labor market

Table 2

Comparative table to understand the characteristics of different photovoltaic projects, in green the ANaV project.

Preliminary environmental assessments have consequently led to optimize the ANaV photovoltaic technology, which is the most performing, in relation with the reference geographic context (flatlands in the municipality of Cerignola, Foggia Province in Puglia Region – Italy).

The geographic location and the characteristics of the ANaV project are represented in the following images (Figures 2 and 3).

Figure 2.

Geographic position of Cerignola site of the ANaV project.

Figure 3.

Detail of the site of the ANaV project.

The ANaV Project allows a suitable realization of the initiative in the environmental context, safeguarding agricultural production and, simultaneously, positively influencing the botanic, vegetational, and wildlife contexts of the area.

The visual characteristics of the ANaV project are represented in the following representations (Figure 4) [3].

Figure 4.

Reconstructions of the ANaV environment.

The ANaV project is made up of modules on “single-axis trackers” for a total capacity of 99.42MWp, suitably elevated from the ground and positioned in such a way as to be best suited to agricultural activity on the same ground surface. (Figure 5).

Figure 5.

Plan view of the ANaV project.

The photovoltaic modules (double-sided with nominal unit power of 605 Wp) are 1.3 × 2.2 m in size, and 4 cm thick. They are in pairs, mounted horizontally with respect to the main axis of the tracker. Twenty-eight modules will be mounted on each single-axis tracker.

The special structure of photovoltaic panels planned for the ANaV system allows high flexibility in agricultural interventions both for machine accessibility and for the selection of crops and cultivation methods (Figure 6).

Figure 6.

Design dimensions for the ANaV system.

The panel height from the ground ensures the proper airing in the underlying area, favoring the normal growth of herbaceous vegetation and, contemporarily, preserving the normal indigenous microbial activity of the soil; also, rainwater can flow below without interfering with the normal underground drainage and storage.

In addition, the position of panels in parallel, equidistant rows, enables a rational organization of cultivations and rotations and/or cultivation changes.

The cultivations envisaged by the ANaV project [4] produce a high remuneration per hectare in front of high demands for labor. Their nature of root crops requires cultivation in rows, that are well suited to the belt structure of the ANaV system. Similarly, the reduced height gain makes it possible to position some rows also in the area occasionally shaded by the tilting photovoltaic panels. Moreover, they do not require bulky machines that could damage the panels.

The agricultural cultivations envisaged by the ANaV project are economically effective in the agro-food district of Cerignola, with a supply chain of propagating material (plants), cold storage, processing rooms, and transport systems.

Crops have been positioned by dividing the full land into four macro-areas, based on the internal roads that actually allow the maneuvering of agricultural vehicles (internal roads are 10 m wide, so maneuvering is easy) [5].

Each macro-area is characterized by cultivation continuity (Artichoke, Asparagus, Cereals/Legumes), with the introduction of a belt of melliferous plants every 8 rows.

The belts cultivated with melliferous plants can also be crossed by vehicles since the species selected to give the ground strong stability and have good crushing resistance. For example, during the hand harvesting of the artichoke or the asparagus on these belts, trainers can be used for carrying the produce (Figure 7).

Figure 7.

Plan view of the crop layout in year 0.

Considering the planned rotations, at the end of a profitable life of multiannual crops (artichoke and asparagus)—expected to be 5 years—the surface for artichoke cultivations will increase up to 60 hectares total (Figure 8).

Figure 8.

Plan view of the crop layout in year 5.

The surface increase for artichokes rather than cereals/legumes also leads to a high increase in the profitability of the ANaV system thanks to the high remuneration of this horticultural production.

It is emphasized that the high innovation engendered by the ANaV system is due to the maximization of the cultivable surfaces in the installation area.

In fact, the fenced area of the ANaV system, corresponding to 141.28 hectares, is divided as follows:

• 124.28 ha for agricultural use;

• 10.80 ha are represented by a 1 m-wide belt under the photovoltaic modules that cannot be used for agricultural purposes since it is shaded by the modules for more than 6 hours a day;

• 5.39 ha are used by roads, electrical substations and by the water storage tank (for irrigation);

• 1.19 ha are occupied by a northern triangular area that will be used for agricultural activities and for the photovoltaic installation (a small office, a shelter for agricultural vehicles, storage of agricultural produce and lodgings for laborers).

Therefore, excluding the unproductive parts represented by roads, water storage tanks and different annexes, only 7.6% of the surface cannot be used directly for agricultural cultivations. However, it must be recalled that the hives are located on this area.

4. Conclusions

The ANaV project is made up of modules on “single-axis trackers” for a total capacity of 99.42MWp. The project has a usable agricultural area of 124.28 ha (89.32%) including the sub-panel belts and the green natural belts. Only 7.6% of the surface cannot be used directly for agricultural cultivations.

The ANaV project is an example of environmental “innovation” that shows it is possible to reconcile agricultural production, the increase of naturality, and photovoltaic power production in a sensitive geographic context. The Project allows a suitable realization of the initiative in the environmental context, safeguarding agricultural production and, simultaneously, positively influencing the botanic, vegetational, and wildlife contexts of the area.