How Much Longer Can We Tolerate Further Loss of Farmland Without Proper Planning? The Agrivoltaic Case in the Apulia Region (Italy)

Abstract

The energy transition from fossil fuels to renewable sources is a key goal for the European Union, among others. Despite significant progress, Italy lags far behind the EU’s target of generating 55% of its electricity from renewables by 2030. The Apulia region in Italy needs to achieve an additional 7.4 GW of installed renewable energy capacity compared to 2021. Renewable energy installations, particularly photovoltaic systems, require land that may compete with other uses like agriculture. This can lead to land-use changes that disrupt agricultural activities. Agrivoltaics (AV) offer a possible solution by allowing energy production and food growing on the same land, which can help alleviate conflicts between energy and food needs, although concerns about landscape impact remain. This study emphasizes the need for effective spatial planning to manage these risks of land use changes and quantify possible agricultural land occupation. A GIS-based analysis was conducted in Apulia using a three-step approach to assess land use and potential AV opportunities: (a) the land protection system identified by the Apulian Landscape Plan was used to obtain a Constraint Map; (b) the agricultural land use and capability classification together with land slope and exposure was used to obtain the AV Availability Map; and (c) agricultural land conversion scenarios were developed to quantify the potential capacity of future AV installations. The results showed that a 0.25% occupation of utilized agricultural land would allow a regional installed AV capacity of 1.3 GW, while doubling this percentage would double the installed capacity to 2.6 GW. The areas potentially involved by AV installations would be 3.25 and 6.50 thousand hectares, reaching 17.5% and 35.0% of the 2030 total renewable energy target. These figures should be considered a reasonable range of AV development in the region, which can contribute both to the energy transition and the support of the agricultural sector, especially in marginal areas.

1. Introduction

The European Union aims to reduce greenhouse gas emissions by 55% from 1990 levels by 2030 [1]. The ecological energy transition refers to a comprehensive climate change mitigation strategy that involves a shift from fossil fuels to renewable energy sources (RES), which directly entails a technological shift but also has deep economic, social, cultural, environmental, political, and, crucially, large land implications [2,3,4,5,6].

The provision of renewable energy through photovoltaic (PV) installations is considered one of the best ways to accelerate the energy transition due to the low and competitive unit cost of energy production achieved by this technology today [7]. While the number of PV installations is growing rapidly around the world, their implementation often leads to land-use conflicts between food and energy production [8]. There are also landscaping issues with PV systems, which are often high-capacity systems with large land footprints [9,10]. These land-use conflicts and landscape impacts recall the need for rigorous spatial planning approaches [11].

1.1. The Renewable Energy Transition in Italy

Italy is trying to find a realistic path that will lead to a transition to renewable energy in line with the European Union (EU) targets set out in the Fit For 55 (2021) and Repower EU (2022) packages. The National Energy and Climate Plan [12] sets a target of 55% of electricity from renewable sources by 2030, and net climate neutrality by 2050. Looking at Italy’s annual energy production (totaling over 320 TWh), more than a third (36%) is now generated by renewable energy sources, and PV has a share of 28% of electricity production from renewable sources [13]. Of the total target of 131 GW of renewables by 2030, 80 GW is expected to come from solar [14]. At the end of 2022, Italy had a cumulative capacity of 25 GW, which means that to meet its 2030 target, installed solar power will need to grow by 55 GW in just a few years [15]. Despite significant progress, Italy is seriously lagging behind in meeting its 2030 renewable energy target.

1.2. Agrivoltaic as a Possible Solution to the Land–Energy Conflict

Agrivoltaics (AV) is a system that combines renewable energy production from photovoltaic panels with agricultural activities and has emerged as a novel approach to potentially increase land productivity while addressing climate change [16].

In the AV solution, large areas of agricultural land can be made available for energy production while maintaining their agronomic use. Various benefits can be associated with AV systems, such as providing shade and protecting crops from extreme weather conditions (heat waves, for example), creating a beneficial microclimate that reduces temperature, evapotranspiration, and wind speed under the system [17]. By creating these synergies, AV systems could increase crop resilience to climate change [18]. Overall, the use of AV is very diverse and there are several farming practices that can be combined with different AV systems [19]. These applications include horticulture, orchards, viticulture and olive groves, arable farming, permanent grassland, and grazing [20]. If well designed, AV systems also have the potential to conserve biodiversity on uncultivated land and restore ecosystem services such as regulating climate, water, soil, and air quality [21].

1.3. Agrivoltaic and Social Acceptance of Renewables

As with other renewables such as wind turbines, the introduction of conventional PV into the landscape is often met with resistance and opposition from local communities and several stakeholders [22,23]. Although social opposition to PV is usually directed at ground-mounted PV systems, AV systems may face similar opposition due to their similarities to conventional PV, especially in terms of landscape impact. The different types of AV systems, each with their own technical, structural, and configurational characteristics, can profoundly change the characteristics and features of the landscape in a number of ways. These changes, in turn, have led to concerns and public opposition. The reasons for this opposition can be diverse, ranging from soil sealing to agricultural land use change, from threats to biodiversity to impacts on landscape and cultural heritage.

On the other hand, AV can also expect greater rates of public acceptance compared to conventional PV due to the spatial continuity of agricultural land use and the potential increase in crop yields [24]. Beyond the technical benefits that could increase energy generation and food production, AV technology can also bring potential economic and social benefits to farmers [20] through the diversification and increase of incomes [25,26] resulting from the sales of both electricity and agricultural products [27], as well as the possibility of expanding employment opportunities [28].

1.4. AV Land Suitability Assessment

While common for PV and wind turbines, there are few studies on land suitability specific to AV. In Japan, a Geographical Information System (GIS) study on AV has identified ‘good AV practices’ and provided a case study of the town of Ine in Kyoto Prefecture [29]. Only marginal farmland was selected for AV expansion, with no additional geographical or socio-economic input. A GIS-based study of Canada’s AV potential found that converting 1% of existing farmland to AV systems could be enough to meet Canada’s energy needs [30]. Elkadeem et al. [31] described an AV-specific GIS multi-criteria decision analysis (MCDA) method for the Swedish territory, based on a range of criteria including irradiance, precipitation, water stress, and seasonal evapotranspiration, which identified 8.6% of the country’s total area as suitable for AV systems. A similar approach has been undertaken for Gunungkidul Regency in Indonesia [32]. Criteria such as climate, land use, ease of connection to the power grid, and nearby water resources were integrated with a number of other constraints. Recently, Fattoruso et al. [33] developed a methodological framework for an advanced agrivoltaics land eligibility analysis at a regional level, in Italy, based on a spatial multicriteria analysis. The challenge was to identify the many factors that can affect land suitability for agrivoltaics systems and combine them to maximize energy and agricultural yields while minimizing the impact on the surrounding landscape. In 2025, Reher et al. [34] presented a multi-attribute decision-making (MADM) analysis to identify suitable areas for AV systems in Flanders, where commercial AV systems are beginning to be deployed. They began by identifying techno-agro-socio-economic criteria applicable to AV land suitability, assigning weights to the main evaluation criteria, and defining restriction criteria for areas where AV would be unsuitable. Dere et al. [35] utilized a systematic decision-making methodology to select and review potential sites for AV investments and generated suitability maps for five cities in Turkey. Majumdar et al. [36] used a GIS-based spatial analysis framework to identify optimal agrivoltaic sites in the rapidly growing Phoenix Metropolitan Area (USA), taking into account land use patterns, environmental constraints, and socio-economic factors. Focusing only on permanent crops, Rösch et al. [37] incorporated socio-technical criteria into their GIS analysis, showing that 79% of the suitable areas are concentrated in southern Germany. The suitability criteria include solar radiation, slope, and landscape aspects, without applying any weighting procedure. More recently, Hauger et al. [38], quantified available agricultural land and identified optimal locations by integrating GIS with the Analytical Hierarchy Process (AHP).

1.5. Objectives of the Work

In order to properly govern the development of AV systems in a region, it is important to establish land-use policies that can assess eligible land, regulate available areas, and manage the pace of AV implementation while accommodating changes in landscape configuration and minimizing possible impacts [24].

The objective of this work is to develop a methodological framework and a case study application to support land use planning for the sustainable implementation of AV systems at a broad territorial level, typically regional. The aim of this study is to provide a spatial planning methodology to identify the potentially available areas for the installation of AV systems in the Apulia region, taking into account the land restrictions and constraints imposed by national and regional legislation, as well as a set of ecological, hydrogeological, and cultural protection criteria. At the same time, it is intended to show the possible capacity of future AV deployment in the region, taking into account the “burden share” assigned to the Apulia region by the government, which should be fulfilled by all types of renewable energy sources, including AV systems, by 2030. For this reason, we have proposed two possible scenarios, assuming that a certain percentage of the UAA (Utilized Agricultural Area) would be dedicated to AV.

We can therefore define this work as a useful exercise in spatial planning in the agricultural sector to counteract the growing aggression of agricultural land and the risk of drastic changes in land use or landscape alteration. How much agricultural land can be used for these AV systems? What contribution could this land offer in terms of maximal power capacity deployed? Without a specific planning threshold or a credible range of available agricultural land, the AV deployment process risks getting out of control.

The significant innovation of this paper is that it is not about the adoption of specific “land suitability” procedures, as generally reported in the literature and referred to in the previous (Section 1.4), but rather about the adoption of a preliminary, extremely useful, and necessary procedure that we could define as “land availability” assessment. Land availability comes first and is a prerequisite for carrying out land suitability. Only once the available land has been quantified (and the energy target has been met) it is possible to proceed with a suitability analysis, taking into account a certain number of criteria, in order to identify and match land categories to specific AV solutions. This latter objective of “land suitability” was not included in the analysis carried out in this work, as the focus was instead on the first, preliminary objective of “land availability”.

2. Materials and Methods

2.1. The Study Area

In Italy, the average annual insolation varies from 3.6 kWh/m²/day in the north to 4.7 kWh/m²/day in central-south Italy, reaching up to 5.4 kWh/m²/day in the Sicilian region, in the extreme south. Particularly favorable geographical areas for high irradiance are the southern coast of Sicily, southern Sardinia, and southern Apulia (Figure 1A), especially the Salento peninsula: Taranto (TA), Brindisi (BR), and Lecce (LE) provinces, as can be seen from the high density of PV installations in this area (Figure 1B). In these areas, it is possible to harvest up to 2000 kWh/m² per year, while in the rest of Italy, the figure ranges from 1750 kWh/m² in the Tyrrhenian belt (Italian west coast of the Mediterranean Sea) to 1300 kWh/m² in the Po Valley or the Alps (northern Italy).

The specific study area in this work is the Apulia region in south-eastern Italy. Apulia is divided into six provinces, from north to south: Foggia (FG), Barletta–Andria–Trani (BT), Bari (BA), Taranto (TA), Brindisi (BR), and Lecce (LE), as shown in Figure 1A.

Its territory is mostly flat (53% of surface <300 m above sea level), rather hilly (45% of surface between 300–600 m above sea level), and only minimally mountainous (only 2% of surface >600 m above sea level), making it the least mountainous region in Italy. This characteristic, together with its ideal sunshine regime, makes the region particularly suitable for solar energy production.

The climate is typically Mediterranean, with semi-arid summers and mild winters.

2.2. Past and Future of Solar Energy in the Apulia Region

By 2030, the Apulia region will need to achieve an additional 7.4 GW of installed renewable energy capacity compared to 2021. This is the target defined at the national policy level (Ministerial Decrees dated 21 June 2024). Using the same national ratio of total renewables to PV of 0.61, the regional PV target should be 4.5 GW. To achieve these impressive results on time, it is necessary to rely on high-capacity, utility-scale PV systems. This inevitably means that PV installations take up a very large area. However, in the last two decades, the Apulia region has seen already a fast increase in the number and size of PV plants. With reference to the 2021 figures [40], the national record in terms of installed power is indeed in Apulia, with 2900 MW (13.4% of the national total); the same region also has the highest average plant size (53.4 kW) and the highest electricity production (3839 GWh). In addition, from 2010 onwards, the majority of these installations (70%) have been implemented with PV systems built directly ‘on the ground’, i.e., completely covering the soil, leading to a worrying conversion of land use from agriculture to energy. This is now considered unsustainable and no longer allowed [41]. When it comes to developing new PV installations in agricultural lands, the only acceptable solution is now AV systems. In any case, PV installations in the Apulia region have been more ‘aggressive’ compared to other Italian regions, both in terms of the absolute number and size of PV systems, and in terms of their relative incidence on the land, i.e., surface density (Figure 1B).

This kind of implementation has led to general discontent, public protests, conflicts, a crisis of social acceptance, and even an ideological dispute between environmental organizations. On the one hand, there is the need to meet the ambitious targets set by the EU strategy to reduce net emissions by at least 55% by 2030 compared to 1990 levels.

The significant increase in the number and size of renewable energy installations requires the assessment of their impact on the landscape, the mitigation of ecological and biodiversity threats, and the protection of cultural and historical heritage values of the region.

2.3. Regulatory Framework on Renewable Energy Installations

From 28 October 2024 to 16 November 2024, the Apulia region held a public consultation to collect opinions and suggestions on the Draft Law no. 222 of 23 October 2024, aimed at identifying eligible, available, and unavailable areas for the installation of renewable energy systems, considering the implementation of two national ministerial decrees dated 8 November 2021 and 21 June 2024, respectively.

With regard to renewables, the Italian regions are required to identify the following types of areas:

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Eligible areas: areas whose characteristics are fully compatible with the installation of renewable energy systems; for example, areas for the reclamation of polluted sites, abandoned quarries and mines, areas adjacent to railroads and within airports, agricultural areas within a buffer of 500 m from industrial areas, areas within industrial zones, areas adjacent to the highway network, etc. For these areas, there is an expedited and simplified permitting process for the installation of renewable energy systems.

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Unavailable areas: areas whose characteristics are incompatible with the installation of renewable energy systems by taking into account a range of protection criteria, i.e., restrictions, limitations, and constraints.

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Available areas: include areas other than the first and second categories previously defined, in which it would be possible to install the systems by applying the ordinary authorization regimes.

2.4. The Methodological Approach

Having defined, in Section 2.3, the different land types recognized by the legal framework with respect to renewable energy installations, the approach taken in this work has been to translate these categories into a GIS-based procedure for identifying and mapping these areas, as well as quantifying their extent. Figure 2 schematically shows these land types and the relationship between them to provide a better understanding of their composition and characteristics.

Considering the entire territory of the Apulia region, a GIS-based assessment of “land availability” was carried out by applying the procedures described in the following sub-sections.

2.4.1. Estimation of Available AV Agricultural Land

The available areas for renewable energy sources have been selected according to the criteria presented in the Apulian Landscape Plan (ALP) [42]. The ALP aims to promote sustainable socio-economic development and mindful use of the regional territory, also through the preservation and recovery of specific aspects and characteristics related to the social, cultural, and environmental identity of the region, to be taken into account in all processes related to landscape planning and management. Specifically, ALP identifies a composite set of territorial values to be protected, and the combination of all these constraints forms what is known as the regional ‘protection system’. In particular, the above-mentioned Apulian draft law no. 222 of 23 October 2024 considers this ‘protection system’ as the set of constraints to be taken into account in the definition of areas eligible for the installation of renewable energy systems.

This “protection system” consists of three different categories (each forming a subsystem), which are listed in

Table 1. List of the protection criteria and constraints considered in the analysis according to the Regional Landscape Plan and the Hydro-Geological Plans.

Protection Criteria and Constraints	Description
(a) Areas of ecological and environmental importance 1	(1)
Botanical and Vegetational components	Woods + 100 m buffer; natural pastures, shrublands, wetlands.
Protected areas and naturalistic sites	Natural parks + 100 m buffer; other sites of naturalistic interest.
(b) Areas of anthropological, cultural, and historical relevance 1	(1)
Cultural and settlement components	Historical and cultural sites + buffer of 100 m; relevant rural landscapes; areas of archeological interest + 100 m buffer; sheep tracks network + 100 m buffer.
Landscape components	Scenic roads + 1 km buffer; view cones; scenic places + 1 km buffer.
(c.1) Areas of hydro-geomorphological vulnerability 1	(1)
Geomorphological components	Slopes greater than 20%; blades and ravines; dolines; caves + 100 m buffer, geosites + 100 m buffer; sinkholes + 50 m buffer; dune belts.
Hydrogeological components	Coastal territories + 300 m buffer; territories contiguous to lakes + 300 m buffer; rivers, streams, watercourses + 100 m buffer; hydrographic network as a link to the ecological network + 100 m buffer; springs + 25 m buffer; areas of hydrogeological risk.
(c.2) Areas of hydro-geomorphological vulnerability 2	(2)
Hydrological hazard	- High hazard (HA): areas subject to flooding with a return period ≤ 30 years. - Medium hazard (MH): areas subject to flooding with a return period between 30 and 200 years.
Geomorphological hazard	- High hazard (PG3): areas affected by active or quiescent landslide phenomena. - Medium hazard (PG2): areas characterized by the presence of two or more geomorphological factors predisposing the occurrence of slope instability and/or stabilized landslides.

(1) From the Apulian Landscape Plan (ALP); (2) From the Hydro-Geological Plan (HGP) by the River Basin Authority (RBA).

: (a) areas of ecological and environmental importance; (b) areas of anthropological, cultural, and historical relevance; and (c) areas of hydro-geomorphological vulnerability.

Correspondently, in this study, we considered the complete list of protection system components identified by the ALP as constraints. Moreover, we decided to consider as additional constraints the areas defined in the Hydro-Geological Plan prepared by the River Basin Authority (RBA) and identified as areas of high and medium hydro-geological and geomorphological hazard, also listed in Table 1. These latter areas partially overlap the hydro-geomorphological structure identified by the ALP ‘protection system’.

The GIS software ArcGis 10.1 was used to spatially process all the geodata for the entire Apulia region, reported at the provincial level (FG, BT, BA, TA, BR, LE).

Three methodological steps were taken to process the spatial data.

• As a first step, the analysis was carried out to identify, map, and quantify available land areas for the installation of renewable energy systems, taking into account a series of specified land protection criteria, restrictions, and constraints, as provided by national and regional legislation. This procedure answers an essential and unavoidable question: how much land do we have potentially at our disposal for the installation of renewable energy systems, while safeguarding the land that, for various reasons, is the most sensitive or valuable and must therefore be excluded? To this end, a ‘Constraint Map’ was created. This map shows which areas are theoretically available for renewable energy installations. It was produced by applying the ‘union’ function of all the protected and constrained areas listed in Table 1. The sets of applied criteria are intended as exclusion/inclusion criteria. Each criterion is represented by a digital map, formalized by a Boolean operator applied to the vectors of the map. This ‘union’ function combines multiple sets into a single set that contains all unique elements from the given sets. It ensures that there are no duplicate values in the final set (Figure 3A).

2.

The second step is specifically focused on AV systems that, for obvious reasons, can only be installed on agricultural land. The unconstrained agricultural area that could be used for AV systems and that also met certain selective requirements was calculated. The applied criteria were related to the land capability and certain technical feasibility characteristics in order to quantify the potential land available for AV systems. In this second step of the assessment, it was necessary to preliminary select only and exclusively agricultural land use types from the regional Land Use Map (LUM) [43] and intersect them with the Constraint Map. It was then assumed that the best (most fertile and productive) agricultural land should not be used for AV installations, but only land with relatively lower production potential. In this way, the importance of preserving farmland where valuable, typical, and certified crops are grown was emphasized. Accordingly, the Land Capability Classification (LCC) [44] was used to evaluate the productive potential of the agricultural land. LCC was developed by the USDA Soil Conservation Service in 1961 and adopted by the Food and Agriculture Organization (FAO) in 1974. The LCC system identifies eight soil classes with increasing restrictions on specific uses. The first four classes show the capability for agriculture, while from the fifth to the seventh class, the capability is limited to pasture and/or forest. In the eighth class, no human activity is possible. Class I and II lands are those with better agricultural production potential and fewer restrictions; therefore, they were not further included in the analysis. On the other hand, Class III and IV lands are more restricted in some way for agricultural use and were therefore included in the analysis. In short, only agricultural classes belonging to Class III and IV of the LCC were extracted and used for the subsequent processes. It was also decided to consider the LCC classification with respect to agricultural land use without irrigation support for crops.

Other selected AV feasibility criteria considered in the analysis were the slope of the terrain and its orientation (Figure 3B). The terrain slope affects both the optimal conditions for the orientation and inclination of the PV modules and the technical feasibility of the PV plant. As reported in the literature, the maximum slope that makes installation technically feasible is generally set at 15% [45,46]. As slopes become steeper, the installation of PV systems raises issues of soil erosion and foundation instability, making installation more difficult and costly. Considering the geographical orientation (azimuth) of the AV system, its effect is combined with the slope and greatly affects the technical feasibility of the plant; for low slopes, the orientation is irrelevant, but on steeper slopes, the orientation of the site is a constraint, and only south-oriented terrains can be considered. Large, high-capacity, utility-scale PV systems can only be installed on flat or low-slope land conditions (<5%); when the slope is limited and still acceptable (5–15%), solar installations should be built on south-facing land. Therefore, it was assumed that the available areas should meet one of the following conditions: (a) land with a slope ≤ 5%; (b) land with a slope between 5 and 15% facing south (between 135 and 225 angular degrees). To obtain the Availability Map, the considered land capability classes, together with land slope and orientation constraints, were processed by using an ‘intersect’ function (Figure 3B). This function calculates the overlapping area of all the three considered conditions, i.e., the areas in common to all features.

3.

Finally, the third step was dedicated to the development of two simple scenarios reflecting a given land allocation for AV systems on a regional scale. In particular, it was hypothetically assumed that 0.25% and 0.50% of the agricultural area (a fraction of the UAA) could be reserved for AV installations. In this way, it was possible to estimate what the actual contribution of the Apulia region and its provinces could be to the fulfillment of the so-called “burden share”, i.e., the total capacity for AV installations, and to verify the possibility of achieving the target defined at the national policy level with respect to the region.

2.4.2. Census Data on Agricultural Land Use

Parallel to the previous assessment (Section 2.4.1), the dynamics of agricultural land use have been analyzed over a period of almost forty years. For this purpose, the data from five consecutive agricultural censuses (1982, 1990, 2000, 2010, and 2020) were processed [47]. The total and utilized agricultural area (TAA and UAA, respectively) were considered, together with the so-called non-utilized agricultural area (NUA). The NUA includes all the land that, for whatever reason (economic, social, or other), is not used for agricultural purposes. However, it is land that can be used for agriculture with ordinary and normally available means.

If the NUA is large and shows an increasing trend over time, this could reduce the pressure caused by an increasing rate of renewable installations on agricultural land. Conversely, if the NUA tends to shrink over time, it means that production pressure on agricultural land is increasing, and thus competition for alternative land uses is also growing. In other words, NUA can be thought of as a kind of “land buffer” with respect to potential land use changes.

3. Results

3.1. Solar Energy Time Trend

It should be emphasized that the Apulia region has already seen a significant installation of PV systems (as well as wind turbines) in recent years; the latest target for 2030 adds another large number of installations to an already problematic past in terms of agricultural land occupation and land use change. The pace of this PV development will even increase compared to recent years. Figure 4 clearly shows how the two reported lines (the national and the regional lines, respectively) see a sudden increase in their slopes starting in 2022, i.e., at the beginning of the period considered in the National Energy and Climate Plan (NECP) [12].

From 2022 onward, the trends shown in Figure 4 are forward-looking and identify a period in which 10 GW of PV installations per year are expected to be developed nationally, and 1 GW per year regionally. As can be seen from the Figure 4, Apulia contributes about 10% of the national PV installation capacity quite regularly over time.

Looking at the spatial density of PV systems, expressed as the ratio of installed PV capacity to surface area (kW km⁻²), Apulia has always had the highest concentration among all the other regions; therefore, well above the national average. This condition has been consistently confirmed over the past decade (as shown in Figure 5), and even earlier. Looking at 2022, the PV spatial density in the Apulia region was nearly twice as high as the average in Italy.

3.2. Agricultural Land Use

At the national level, the area of TAA, UAA, and NUA has declined impressively over time (Figure 6A). From 1982 to 2020, TAA decreased by nearly 6 million hectares (more than 25%); similarly, UAA decreased by 3.3 million hectares (more than 20%) over the same period. In the Apulia region, the downward trend of TAA and UAA was proportionally less pronounced than at the national level, especially in the last 20 years, but it was still considerable, equivalent to a decrease of 282 thousand hectares (about 17%) and 230 thousand hectares (about 16%) from 1982 to 2020, respectively (Figure 6B).

The NUA values also decreased proportionally even more than the TAA and UAA values, i.e., by 66% at the national level and by almost 50% at the regional level between 1982 and 2020. This indicates a strong pressure on the remaining agricultural land.

In Apulia, the TAA covers 70.5% of the entire regional territory, and the UAA 66.5%: both figures represent the highest values among the Italian regions. Apulia is the third region in terms of absolute TAA and UAA extension (after the two islands of Sicily and Sardinia). On the other hand, Foggia (FG, one of the Apulia provinces) has the largest TAA and UAA in Italy with respect to all other provinces in Italy.

It can be assumed that, on average, at least 2.5 hectares of agricultural land are needed to install an AV system with a peak power of 1 MW. This particular value takes into account the fact that in Italy a 1 MW ground-mounted AV system occupies an average of 1.8 ha, while in Apulia, it reaches 2.0 ha [40]. It follows that, as a first approximation and for the same capacity, a utility-scale AV system will have at least 25% more surface area, i.e., 2.5 ha [48]. This estimate allows an initial, purely indicative, and arbitrary consideration, as developed below. If, for the sake of analysis, the entire NUA were to be allocated to AV systems, what would be the actual installable capacity in the provinces and in the entire region of Apulia resulting from this calculation?

Table 2. Non-Utilized Agricultural Area (NUA) and Utilized Agricultural Area (UAA) in relation to the provinces of the Apulia region, together with the incidence (expressed in %) of the NUA on the UAA. The AV capacity calculation was done under the (purely theoretical) hypothesis that all NUA would be used for this purpose.

Province	NUA	NUA/UAA	AV Capacity
	(ha)	(%)	(GW)
BA	3145	1.20	1.26
BR	1593	1.32	0.64
BT	866	0.80	0.35
FG	4154	0.82	1.66
LE	1744	1.14	0.70
TA	2678	1.79	1.07
Total (Apulia)	14,183	1.10	5.67

shows the results.

It could be argued that the purely theoretical assumption of full utilization of the regional NUA for AV systems would allow 5.7 GW of peak power to be installed, a significant amount compared to the total 7.4 GW required and to be achieved by 2030, particularly considering that the specific PV target should be 4.5 GW. However, as mentioned, this is only an indicative, certainly not realistic, rough estimate.

3.3. Estimation of Agricultural ‘Available Land’

The geographical distribution of each of the three components of the ALP “protection system”, along with the HGP vulnerability components, are shown in Figure 7A–C, while the overall representation of all components together is shown in Figure 7D. This last map represents what we have called the Constraint Map.

Table 3. Constrained areas according to the “protection system” of the Apulia region. The areas are reported according to the three criteria considered in the analysis (see the footnote legend).

Province	Terr. Area (ha)	Area EE (ha)	Area ACH (ha)	Area HGM (ha)	Constr. Area (ha)	Constr. Area (%)
BA	382,478	134,040	223,251	107,839	292,025	76.35
BR	183,942	20,394	120,211	22,321	130,189	70.78
BT	153,003	51,258	77,431	46,624	108,001	70.59
FG	695,679	261,694	359,498	336,361	511,608	73.54
LE	276,230	34,937	210,048	37,193	217,430	78.71
TA	244,068	99,967	136,262	87,292	187,453	76.80
Apulia	1,935,400	602,290	1,126,701	637,630	1,446,706	74.75

Legend: Terr. Area = territorial area of the provinces and the region as a whole; EE = areas of ecological and environmental importance; ACH = areas of anthropological, cultural, and historical relevance; HGM = areas of hydro-geomorphological vulnerability. Constr. Area: constrained areas are the result of applying the ‘union’ function of all the protected and constrained areas (i.e., EE, ACH, and HGM).

shows the entire territorial areas of the Apulian provinces together with the constrained areas related to the “protection system” (EE, ACH, and HGM).

The total constrained areas shown in Table 3 cannot be the simple sum of the three components, but the result of applying their “union” (a specific GIS operator), which takes into account any overlapping areas. The total regional overlapping area (areas where the different constraints are jointly applied) is 64%. Considering the whole Apulia region, the total constrained area is about 75% of the entire territory. The highest relative constrained area is recorded for LE province (79%), while the lowest for both the provinces of BR and BT (71%). The ACH area is almost twice as large as the EE and HGM areas, representing 80% of the total constrained area. Concerning the provinces BR and LE, it is noteworthy that the EE and HGM areas are quite low, while the ACH area is high in relation to the total constrained area. Differently, the FG province shows a high relative incidence of HGM vulnerable areas.

Once the Constraint Map was obtained, the first step of geospatial processing was completed (Figure 3A). The second step is the following.

Table 4. Land allocation by agricultural capability classes for each province and the region as a whole, and their relative proportions with respect to the total land area.

Province	A Terr. Area (ha)	B LCC I–IV (ha)	C LCC III–IV (ha)	D B/A (%)	E C/A (%)
BA	382,478	290,095	213,153	75.85	55.73
BR	183,942	152,132	93,726	82.71	50.95
BT	153,003	117,374	94,470	76.71	61.74
FG	695,679	479,233	408,266	68.89	58.69
LE	276,230	204,449	152,844	74.01	55.33
TA	244,068	162,504	132,876	66.58	54.44
Apulia	1,935,400	1,405,788	1,095,334	72.64	56.59

Legend: A = territorial area of the provinces and the region as a whole; B = agricultural areas with land capacity I to IV; C = agricultural areas with land capacity III to IV; D = relative ratio of B to A; E = relative ratio of C to A (both expressed as percentages).

shows the allocation of agricultural land (extracted from the LUM) in relation to the Land Capacity Classification (LCC).

The Constraint Map was then intersected twice, first with the regional LUM to select only areas of agricultural use. From the areas thus identified, a second intersection was made with the LCC map, further selecting those areas that met the AV feasibility criteria, i.e., land slope and exposure. This second stage of geospatial processing (Figure 3B) allowed us to obtain the final Availability Map.

The area of all agricultural classes (from I to IV) covers about 73% of the total regional territory. A certain diversity can be observed at the provincial level, where BR has the highest value of about 83%, while TA and FG have the lowest values, ranging from 66 to about 69%. If only classes III and IV are considered, the percentage of agricultural land for the whole region drops to about 57%. At the provincial level, the highest values were recorded for the provinces of BT and FG (62 and 59%, respectively), while the other provinces show comparable values ranging from 51 to about 56% (Table 4).

After removing the areas classified as “constrained” (according to the Constraint Map), the AV feasibility criteria were applied, and the AV available areas were mapped for each province and the region as a whole (Figure 8).

Table 5. Allocation of unconstrained agricultural land according to three selected feasibility criteria (see the footnote legend), showing the potential available land for AV installations.

Province	FC.1 (ha)	FC.2 Within FC.1 (ha)	FC.3 Within FC.1 (ha)	FC.2 and FC.3 Within FC.1 (ha)
BA	55,173	54,487	104	54,591
BR	24,725	24,725	0	24,725
BT	33,757	33,056	102	33,158
FG	162,741	159,342	736	160,078
LE	35,782	35,780	0	35,780
TA	42,087	41,982	33	42,015
Apulia	354,264	349,373	975	350,348

Legend: FC.1 = first feasibility criterion: unconstrained LCC III–IV, referring to land without irrigation; FC.2 = second feasibility criterion: as for FC.1 but selecting slope within 5%; FC.3 = third feasibility criterion: as for FC.1 but selecting slope between 5 and 10% facing south; and finally, the last column (FC.2 and FC.3 within FC.1) is the sum of the two land categories and represents the potential available land for AV installation.

shows the unconstrained agricultural land that can be potentially allocated to AV systems (i.e., available land) according to the three successive feasibility criteria (see the footnote legend).

According to Table 5, the total regional area potentially available for AV installations is about 350 thousand hectares, with the province FG expressing the highest availability (160 thousand hectares), much more than the other Apulian provinces, with areas between 25 and 55 thousand hectares. As shown in

Table 6. Territorial areas, utilized agricultural areas, and available areas for AV installations, together with the relative incidence of available areas in relation to territorial and utilized agricultural areas (expressed as percentages).

Province	Terr. Area (ha)	UAA (ha)	Available Area (ha)	Avail/Terr. (%)	Avail/UAA (%)
BA	382,478	262,924	54,591	14.27	20.76
BR	183,942	121,098	24,725	13.44	20.42
BT	153,003	108,270	33,158	21.67	30.63
FG	695,679	505,337	160,078	23.01	31.68
LE	276,230	152,954	35,780	12.95	23.39
TA	244,068	149,542	42,015	17.21	28.10
Apulia	1,935,400	1,300,125	350,348	18.10	26.95

, the potentially available land addressed to AV installations represents, for the entire Apulian region, 18% of the territorial land (maximum value: FG = 23%; minimum values: LE and BR = 13%) and 27% of the utilized agricultural area (maximum value: FG = 32%, minimum value: BR = 20%).

Finally, two separate scenarios were generated, considering a low and a high threshold for the allocation of UAA to the installation of AV systems. The low threshold envisages a 0.25% occupation of the UAA, to be chosen, of course, within the defined available areas. The high threshold, on the other hand, is doubled, i.e., 0.50% occupation of the UAA, again within the available areas.

According to the two scenarios reported in

Table 7. Scenarios of utilized agricultural area (UAA) addressed to the installation of AV systems. Two scenarios are compared: a lower scenario (0.25% UAA) and an upper scenario (0.50% UAA). Simulation results are reported in terms of installed power.

Province	UAA (ha)	Available Area (ha)	Lower Scenario Power Capacity (MW)	Upper Scenario Power Capacity (MW)
BA	262,924	54,591	263	526
BR	121,098	24,725	121	242
BT	108,270	33,158	108	217
FG	505,337	160,078	505	1011
LE	152,954	35,780	153	306
TA	149,542	42,015	150	299
Apulia	1,300,125	350,348	1300	2600

, a 0.25% occupation of agricultural land would allow for a regional installed AV capacity of 1.3 GW, while doubling this percentage (i.e., 0.50%) would also double the installed capacity, reaching 2.6 GW. It is worth recalling that by 2030, the Apulia region will have to reach an additional 7.4 GW of installed renewable energy capacity compared to 2021, including approximately 4.5 GW from PV systems. According to our estimates, with 0.25 and 0.50% of the UAA occupation, it would be possible to reach 18% and 35% of the total 2030 regional renewable energy target, or 29% and 58% of the estimated PV target capacity. It is very important to define the total agricultural area needed to achieve these results. The areas potentially occupied by AV plants would be 3.25 and 6.50 thousand hectares for the first (lower) and second (upper) scenarios, respectively. These areas represent 0.9% and 1.9%, respectively, of the total available agricultural land for AV installations (350 thousand hectares) in the region.

It should be noted that the remaining amount of renewable energy capacity to meet the regional target should come from installations in both eligible and available areas, taking into account renewable technologies other than AV. For this reason, the percentages of land coverage envisaged by the proposed scenarios may be possibly overestimated compared to the actual needs, taking into account, for example, the contribution of wind turbines, another widely used (also discussed and controversial) technology in the region.

4. Discussion

4.1. The Essential Role of Public Land-Use Planning

The current historical phase is characterized by severe climate and energy crises, making action to replace fossil fuels and mitigate climate change compelling and also urgent. The switch to renewables and the substitution of fossil fuels are factors that significantly improve environmental quality and mitigate climate change, but should not jeopardize the landscape, which should be considered a priceless common heritage. Large-scale renewable installation projects and possible landscape degradation are at the center of today’s public debate and social turmoil in Italy, especially in those regions where these installations have reached an impressive land concentration.

In the midst of this ecological transition, we need to emphasize the specific relevance of applying land planning procedures, with the Regional Landscape Plan (in our case the ALP) as a powerful reference tool. Public planning must play a leading role in managing this transition and be able to regulate its territorial deployment without being influenced or pressured by the industrial system and market interests.

4.2. Land-Use Planning and GIS-Based Assessment Procedures

Energy land planning involves a complex interplay of geographic, management, and design decisions [34]. When agricultural land is used to support renewable energy development, especially considering the need for industrial-scale AV systems, the identification and classification of potentially available areas for AV systems becomes paramount [49]. GIS methods and applications play an essential role in any kind of planning process, especially in issues such as energy land-use planning. Before any policy decision is made, a preliminary territorial analysis is needed to identify the resources at stake and the compatibility of their use with other possible development scenarios in the province or region.

In line with the above recommendations, the aim of this study was to develop a methodological procedure to identify agricultural areas available for the installation of AV systems in the Apulia region, using a GIS approach. Specifically, in this study, the analysis was carried out taking into account the regional Draft Law no. 222 of 23 October 2024. Although this law is still in draft form, it should be emphasized that it incorporates some key aspects already established by the ALP and existing national legislation. First of all, this law recalls the definition of eligible areas as defined by national law and distinguishes them from available and unavailable areas. This is a crucial point that should be explained and further clarified (see Section 2.3). “Eligible” land for PV installations is land that is not contested, disputed, or in competition with alternative uses, especially if these uses are economically viable, i.e., land that could be considered “empty” and therefore potentially usable without particular problems (note: of course, no land is actually “empty” and nature is everywhere, as well as the ecosystem services associated to nature). Conversely, if the land can be defined as “available” for potential renewable energy installations, it means that it has been identified by avoiding all the possible territorial constraints and conflicts through proper land use planning. Finally, a land (or more correctly, a “site”) can be defined as “suitable” if it is within the available land area for that specific use (i.e., PV or AV), and also meets certain feasibility criteria, resulting in the site being considered optimal for that type of use.

4.3. Merits of the Applied Methodology

While examples of “suitability” analysis of AV installations are quite common, and there is a good deal of work on the subject in the literature, little or nothing can be found on what we might call “availability” assessment.

However, it should be recalled that the availability assessment concerns a preliminary stage of land use planning and quantifies, in general terms, the available land resources that could potentially be allocated to AV installations. In contrast, the suitability analysis comes later and is more closely related to the nature or type of the AV project and its specific implementation characteristics and technical feasibility, leading to the identification of the most suitable land (or sites) in relation to a set of characteristics (size of the AV installation, types of crops and farming systems, market conditions, etc.).

This approach deserves to be systematically considered and applied by those involved in land use planning in public administration and government agencies. Its value, therefore, goes beyond the single case of application considered here and becomes a tool of wide and diffuse use.

4.4. Objectives Achieved in This Research

The first objective was to quantify the area of what we defined as “available” land for AV installations, i.e., agricultural land without any type of protective restriction or constraint (cultural, historical, geomorphological, landscape, ecological, etc.). This should minimize the risk of impacting the environment and the most representative landscape features. The union of all the constraint layers mapped by the ALP has shown that particular attention has been paid to the protection of the land, as evidenced by the fact that 75% of the total territory of the Apulia region is protected, although differences can be observed at the provincial level.

A second objective goes beyond the simple amount of potential agricultural land to be assigned to AV installations and includes the quality of that land, in other words, soil fertility or land capability class [31,33,34]. Since this study does not aim to promote the uncontrolled installation of AV systems on highly productive and fertile land, it was decided to focus on classes III and IV of the LCC map under non-irrigated conditions. This resulted in a reduction from 73% (classes I–IV) to 57% (classes III–IV only) of the total regional territorial area (Table 4). The final steps of the calculation were to extract the agricultural land from the total and to introduce two feasibility criteria—slope and exposure—in order to select only the more favorable areas of the land potentially available for the AV system. This resulted in a further reduction of the total agricultural areas available for AV to 350 thousand hectares, i.e., a decrease to 18% of the total territorial area (Table 6).

A third objective of this work is to prevent AV installations from becoming an excessive occupation of agricultural land. According to our scenarios, 0.25% and 0.50% of the total regional UAA coverage can achieve 18% and 35% of the total regional renewable energy target (7.4 GW) or, alternatively, 29% and 58% of the regional PV target (estimated at 4.5 GW using the same national ratio of total renewable energy to PV equal to 0.61). The area estimated by the two scenarios represents 0.9% and 1.9%, respectively, of the total agricultural land available in the region for AV installations.

4.5. Farmland Losses

Another result of the analysis carried out in this paper is related to the progressive and persistent contraction of agricultural land. Independent of the “land grabbing”, as some refer to it, due to renewable energy installations (not only PV but also wind turbines), the main problem for agriculture is that the TAA, UAA, and NUA have impressively decreased from 1982 to 2020, as shown by the census data, both at the national and regional levels (Figure 5). There are multiple, deep, and critical stresses that undermine the agricultural sector and trigger the conversion of its land to other uses. For this reason, it should be emphasized that the energy sector should be a leverage factor to promote rural development and support agriculture and not the other way around.

In particular, NUA should not be considered tout court available for AV systems. In this respect, farmers receiving support from the CAP (Common Agricultural Policy) have to comply with EU standards for Good Agricultural and Environmental Conditions (GAEC). GAEC8 states that at least 4% of the arable land of each farm should be devoted to non-productive areas. Although the compulsory nature of this measure has now been released and the measure has been transferred to Eco-scheme 5 (another CAP measure) as a voluntary measure, the fact remains that it is considered useful, if not necessary, to have “ecological focus areas” (EFAs) on the farm. In the Apulia region, NUAs represent about 1% of the UAA (Table 2) and 2% of the arable land, which is well below the given threshold of 4%. Despite these conditions, a maximum and theoretical AV capacity of 5.7 GW could be installed if, hypothetically, all NUAs were potentially dedicated to this use.

4.6. Pressure from the Energy Industry

We have repeatedly pointed out that the Apulia region must reach the threshold of 7.5 GW of energy from renewable sources by 2030. It is estimated that 4.5 GW can be attributed to solar plants. Facing this requirement, which is considered very demanding, the offer of new plants to be installed by energy companies reached the exorbitant figure of 68.26 GW for Apulia alone (more than nine times more the target) and 38.72 GW for PV alone (about 8.6 times more the target) by March 2025. In the province of Foggia alone, new applications for solar power plants amount to 21.52 GW, and for wind power plants to 18.02 GW, for a total electrical capacity of 39.54 GW. These figures are the clearest sign of the technological maturity of the sector, the economic advantage of these investments, and the absolutely favorable climatic and environmental conditions that guarantee excellent electrical productivity. However, all this is incompatible with the preservation of the landscape.

This means that the pressure exerted by the energy industry is very strong, and that the demand for connection to the electrical grid and for the authorization of installations overrides any possibility of effective administrative regulation. These are, in fact, irreconcilable figures in relation to what has been theoretically foreseen, and any balance is therefore in danger of being blown. Once again, the need and urgency for reliable regional spatial planning is reinforced by this overexposed condition.

4.7. Utility-Scale PV Installations as a Component of the Current Energy Transition

PV is a very good technology for deploying distributed energy systems, but unfortunately, roof surfaces and open industrial areas alone are not enough to meet the overall energy target. Small-scale energy systems, although insufficient, are very important because they support bottom-up energy projects and promote citizen participation and their direct responsibility. On the other hand, high-capacity, utility-scale PV installations are considered essential to effectively achieve the binding 2030 and 2050 targets with the necessary speed.

Recently, the Italian Institute for Environmental Protection and Research [50], based on the current total area of buildings in Italy, estimated the net area available for PV installations between 760 and 992 km². Assuming flat roofs and a requirement of approximately 10 m² for each kW installed (i.e., 1 MW = 1 ha), it was estimated that between 76 and 99 GW of PV capacity could be installed on existing buildings. Similar results were obtained in a previous estimate from the energy and strategy research group of the Politecnico di Milano [51], which calculated a total urban surface area of 3481 km², an available urban area of between 680 and 890 km², and therefore a potential installed capacity of between 68 and 89 GW. This energy capacity is exactly or almost enough to cover the increase in total renewable energy foreseen by the NECP until 2030 (80 GW), but not the increase foreseen until 2050 (200 MW).

In any case, there is no doubt that the most reasonable solution should be to install PV systems first on the roofs of new buildings, on public buildings, in industrial areas, in abandoned and reclaimed areas, along the buffer strips of main roads, and wherever the impact on the landscape is negligible. Recognizing that this will not be enough in the long run, it is important that installations are also directed towards larger PV systems that do not require new land occupation, through compatible technologies such as AV installations in rural areas, thus avoiding agricultural land use change and land consumption, the most serious mistakes of the past renewable energy “golden rush”.

4.8. A Wide Range of AV Applications

Properly planned, the deployment of AV systems can reconcile the two goals of generating renewable energy while preserving agricultural land and protecting the landscape.

First, AV systems should be installed in areas where agricultural activity has gradually ceased due to economic and social marginalization. Under these conditions, agricultural land is no longer cultivated, and some tree crops are almost completely abandoned or only occasionally managed. Particular cases are those where some areas have been hit by serious epidemics that have affected crops and caused serious damage. It is worth recalling the almost total destruction of olive groves in southern Apulia by the bacterium Xylella fastidiosa. To date, Xylella has infected and killed more than 21 million olive trees, a disaster that has left behind a ghostly scenario. More than 8000 square kilometers, or 40% of the Apulia region, have been infected. A regeneration plan for olive groves, which is particularly costly, could therefore include the partial implementation of AV systems in combination with traditional or even modern olive groves (intensive and super-intensive olive groves in hedgerows). This implies that part of the capital of the energy industry is also invested in the recovery of the agricultural sector.

Considering Apulia, even in a Mediterranean environment with a hot and dry summer period, the cultural systems that can be associated with an AV installation can be quite varied. Fruit tree crops are the most common (especially olive groves and vineyards). Horticultural vegetables, particularly summer crops, can only be grown if irrigation is available. In more marginal areas, fodder and pasture can also be good companions of solar panels in AV systems, along with melliferous, nectar, and officinal crops.

Another critical issue is the maximum yield reduction compatible with AV [52]. A threshold has not been established by the Italian Ministry guidelines [53], but can be found in guidelines or regulations from other states, both inside and outside the EU. It is reasonable to fear that the absence of this threshold may lead to design and management choices that are contrary to a truly integrated agricultural model, one that is effective for the economic valorization of agricultural activity. In Germany, the standard DIN SPEC 91434 sets a threshold for agricultural yield under AV systems to be at least 66% of the reference yield. In Japan, the legislation allows AV farms to operate only if crop yield is at least 80% compared to before AV installation [54]. Only recently, from the private sector, a standard for AV systems has been issued, which sets a threshold for the agricultural yield of AV systems of at least 70% of the crop yield in open-field conditions [55].

4.9. Some Suggestions for a Properly Planned Energy Transition

In summary, the following are some guidelines that should be followed in order to achieve an effective planning and implementation process for renewable energy sources, also considering AV systems, in the Apulia region (as well as in other regional territories).

• Promote and strengthen the role of land use planning, taking into account a fundamental tool of national legislation, represented by the Regional Landscape Plan. To this end, the culture of public planning must be actively revitalized.
• Unify national rules and standards for identifying eligible areas for installing renewable energy systems.
• Clearly define the quantitative targets to be achieved in the implementation of renewable energy installations (including AV systems) and the maximum areas that can be allocated to such installations, so as to avoid a land-grab race, especially for agricultural land.
• Ensure transparent administrative processes and timely involvement of local communities directly affected by renewable energy projects.
• Promote the quality of AV projects, with particular attention to the suitability of the farming systems applied, their management, the legal form of the farm entrusted with the agricultural management of the land, and the monitoring systems.
• This latter can be done through periodic (once or twice a year) project applications in response to public tenders that allocate precise quotas of energy capacity. This would encourage competition between projects and thus a gradual increase in their quality, as an alternative to a simple administrative logic of “first come, first approved”.

5. Conclusions

While the renewable energy industry is in a frenzy of business opportunities and a large part of public opinion is in turmoil, expressing concerns and organizing protests, the central government as well as the regional administrations (with some exceptions) are standing still and have been doing so for several years, without responding to the urgent demand to guide the energy/ecological transition. This is not conducive to a fair and balanced process and leaves room for ungovernability and approximation in the management of lands and territories, especially considering the agricultural land. There is an urgent need to apply a land planning approach to properly define land use rules to be followed. Land and landscape quality should be considered as an irreplaceable community heritage that requires, as a priority, precise spatial information in order to develop effective guidelines that can overcome the gradually worsening social contrasts on renewable energy sources.

The analyses that were carried out in the present work were intended to serve precisely the forementioned purpose, that is to identify, map, and quantify the areas potentially available for the installation of renewable energy systems, and then, with respect to AV systems, to define the maximum extent or range of agricultural land to be used and that should be considered appropriate to achieve the energy transition goals set by the central government. To this end, a GIS-based methodology, which we have termed a “land availability assessment”, was developed and applied prior to what is usually termed a “land suitability analysis”. This approach should be considered as a preparatory set of information to proceed with planning decisions and to define how to manage the energy target with respect to environmental constraints. As this method has been adopted in a region particularly exposed to the so-called “green energy land grabbing”, it can be confirmed that it is also well suited to other territorial conditions, wherever it is applied.