Shade as the Primary Variable
When solar panels are mounted at heights sufficient for agricultural machinery to pass below — typically 2.5 to 4 metres at the ridge — they create intermittent and partial shade across the parcel. The exact shading pattern depends on panel tilt angle, row spacing, and geographic latitude. For Italian latitudes (roughly 37°N in Sicily to 47°N in the Alps), panel tilt angles between 15° and 30° are common, resulting in shade bands that shift through the day and season.
Crops encounter this shade in two ways: direct reduction of photosynthetically active radiation (PAR) reaching leaf surfaces, and indirect effects including altered temperature, humidity, and evapotranspiration rates. The net agronomic outcome is crop-specific and cannot be generalised across species.
Shade-Tolerant Crops in European Trial Data
European agrivoltaic research, particularly work from the Fraunhofer Institute for Solar Energy Systems (ISE) at Heggelbach in Germany and from projects funded under the EU Horizon programme, has documented crops that show acceptable or improved performance under agrivoltaic conditions:
Potatoes
Potato trials at Heggelbach showed that tuber yield held reasonably well under an agrivoltaic configuration compared with open-field controls in the same season. More notably, the reduction in direct solar radiation during peak summer also appeared to reduce water stress in dry years — a relevant consideration for northern Italian regions prone to summer drought.
Clover and Grass Mixtures
Forage crops including red clover and grass-clover mixtures adapted to partial shade with minor yield reductions. Their low canopy and tolerance of interrupted light made them tractable under panel arrays with standard row spacing.
Lavender and Aromatic Herbs
In Mediterranean-climate trials, lavender showed tolerance of partial shade and, in hot summers, may benefit from reduced heat stress under panels. Italian producers in Provence-adjacent zones have noted that high-value aromatic crops could justify the panel infrastructure costs over a shorter payback period than commodity cereals.
Wheat and Other Cereals
Cereal crops are more demanding of full direct radiation at key growth stages, particularly during grain fill. Trial data from European sites suggests yield reductions are larger for wheat than for shade-tolerant alternatives. Placement of high-density grain crops in agrivoltaic configurations is considered technically possible but economically marginal unless energy revenues are substantial.
The Fraunhofer ISE pilot project at Heggelbach, Germany, is one of the most-cited European agrivoltaic research installations. Published data from multiple harvest seasons covers potatoes, wheat, clover, and celery under the same panel configuration. Results are publicly available through Fraunhofer ISE publications.
Microclimate Changes: Temperature and Water
Beyond light, agrivoltaic installations alter local microclimate in ways relevant to crop physiology and irrigation management:
Temperature Buffering
Panel shading reduces peak soil and canopy temperatures during high-radiation summer days. In hot, dry Italian regions — southern Sardinia, inland Sicily, parts of Calabria — this buffering may extend the productive window for cool-season crops or reduce irrigation frequency during heat events.
Reduced Evapotranspiration
Lower radiation and wind speeds between panel rows reduce crop water demand (evapotranspiration). Some trial sites have documented water savings in the range of tens of percent compared to open-field conditions in the same growing season. For Italian agriculture, where water scarcity is a documented stress in southern regions, this is not a trivial consideration.
Panel Drip Effect
During rainfall, panels concentrate water runoff along panel edges, creating strips of higher and lower moisture deposition. This uneven distribution needs to be accounted for in both irrigation design and crop placement. Row crops planted to run parallel with panel rows are better positioned to average out this effect than those planted perpendicular.
Italian Crop Context: What Grows Where
Italy's agricultural diversity means that the relevant crop set for agrivoltaic compatibility varies significantly by region:
| Region | Typical Crops | Shade Tolerance Assessment |
|---|---|---|
| Po Valley (Emilia-Romagna, Lombardy) | Maize, wheat, soybeans, vegetables | Mixed — vegetables more tolerant than grain |
| Southern Italy (Puglia, Basilicata) | Durum wheat, olives, tomatoes, viticulture | Olives tolerant in early stages; tomatoes show variable response |
| Central Italy (Tuscany, Umbria) | Viticulture, sunflowers, legumes, olive | Legumes generally tolerant; sunflowers less so |
| Alpine Foothills (Trentino, Veneto) | Viticulture, apple orchards, small grains | Orchard crops dependent on specific trellis geometry |
Viticulture and Agrivoltaics: An Emerging Area
Several Italian viticulture research institutions have begun examining whether grapevines — grown on trellises at heights compatible with agrivoltaic panel mounting — can be integrated with overhead panels. The interaction between panel-induced shade, reduced sunburn stress on grapes, and potential impacts on sugar and phenolic content is an active area of inquiry. Published agronomic results from Italian vineyards under agrivoltaic conditions were limited as of mid-2026, with trials ongoing in Puglia and Trentino-Alto Adige.
Configuration Parameters That Matter Agronomically
From an agronomy standpoint, the following panel configuration parameters have the largest impact on crop compatibility:
- Minimum clearance height: Determines machinery access and the degree to which the crop is enclosed in a modified microclimate.
- East-west versus north-south row orientation: Affects how shade bands move across the field and whether crops experience more uniform daily light distribution.
- Inter-row spacing: Wider spacing increases solar access per unit of crop area but reduces total panel capacity per hectare.
- Bifacial panels: Bifacial configurations capture light from panel undersides, potentially reducing the shade cast on crops compared to monofacial equivalents at equivalent output.
- Tracking systems: Single-axis east-west tracking can adjust panel angle seasonally, in principle improving crop light access during winter months when sun angles are low.
The MASAF 2022 guidelines use the concept of Land Equivalent Ratio (LER) — a combined productivity metric comparing agrivoltaic output (energy plus crops) with equivalent separate land areas. An LER above 1.0 indicates that the combined system produces more total value per unit of land than the two activities could achieve separately.
Practical Assessment Before Choosing a Crop
Before committing to an agrivoltaic crop selection on a specific Italian parcel, practitioners typically consider: local solar resource and expected shading pattern from the planned configuration; historical water availability and irrigation infrastructure; regional market prices for potential shade-tolerant crop alternatives; and whether existing equipment is compatible with the clearance height of the planned installation.
There is no universal crop recommendation for Italian agrivoltaic installations. The most defensible position is to treat crop choice as site-specific, based on measured or modelled shading data for the proposed geometry and existing agronomic knowledge of the parcel.