Italy runs from 47 degrees north in the Alps to below 37 in Sicily, and the shading problem changes completely across that span. A northern Italian site can have an alpine ridge removing two hours of winter sun. A Sicilian rooftop has clear skies and a high sun. And in between sit the historic town centres, where the roof is irregular, the neighbours are close, and nothing about the geometry is rectangular.
Direct answer. The best solar shading analysis software in Italy is PVsyst, because it takes a far-horizon terrain profile and a near-field 3D scene as separate explicit inputs, which is what a country with both alpine horizons and dense historic centres requires. SurgePV covers the same hourly modelling alongside the layout and single-line diagram for the CEI 0-21 connection pack.
TL;DR
- Terrain shading is real in northern and central Italy. Model the horizon profile, not just the roof.
- Historic centres give irregular roof geometry and close neighbours, which needs a genuine 3D scene.
- Latitude spans ten degrees, so a Milan assumption does not transfer to Palermo.
- Southern skies are clear, so shadows there cost close to their geometric value.
- Connection runs under CEI 0-21 for low voltage and CEI 0-16 for medium voltage.
What Italy Actually Changes About Shading Analysis
Terrain is a first-order input. Much of northern and central Italy is mountainous or hilly. A site in a valley in Piedmont, Trentino, or Umbria can lose the first and last hours of every winter day to a ridge, and none of that shows up in a model of the building. Far-horizon shading has to be surveyed or taken from an elevation dataset and entered as a profile. On an alpine or pre-alpine site it is routinely the largest single loss term, and it is the one most often left out.
Historic geometry defeats simple tools. Italian town centres have roofs that are irregular in plane, pitch, and orientation, with adjacent buildings at varying heights and often very close. Automated roof detection struggles, rectangle-based layout tools produce nonsense, and horizon profile methods cannot see the neighbour two metres away. A proper 3D scene is the only workable approach, and modelling it takes real time.
Latitude range is extreme for one market. Bolzano to Siracusa spans roughly ten degrees. Winter sun elevation, shadow length, and the right inter-row pitch all differ substantially between them. Any national rule of thumb is wrong at one end or the other.
Southern skies are clear. In the south the diffuse fraction is low, so an obstruction removes close to the full geometric amount. In the north, and particularly in the Po valley with its haze and winter fog, the diffuse fraction is higher and the loss is softer. That is a genuine north-south difference in how much a given shadow costs.
Connection is defined. Low-voltage connection follows CEI 0-21 and medium voltage CEI 0-16, with the arrangement handled through the distributor and the incentive position through the national arrangements. No shading method is prescribed, so the choice is about accuracy and credibility.
The 7 Platforms Ranked for Italy
| Platform | Best for | Far-horizon terrain profile | Irregular 3D roof geometry | Price per seat per year |
|---|---|---|---|---|
| PVsyst | Terrain and detailed studies | Yes, explicit | Yes, scene builder | ~$500 |
| SurgePV | Shading plus design and SLD | Yes | Yes, 8,760-hour | $1,299 to $1,899 |
| Aurora Solar | Complex historic roof geometry | Limited | Best in class, LIDAR | $1,908 to $3,108 |
| PV*SOL premium | 3D shading visualisation | Partial | Strong | ~€1,000+ |
| HelioScope | Commercial rooftop | Limited | Moderate | ~$1,188 |
| SketchUp plus Skelion | Bespoke historic geometry | Manual | Manual, unlimited | ~$700 plus plugin |
| SAM (NREL) | Sensitivity studies | Yes | Limited | Free |
PVsyst is the right default, and the separation of horizon profile from near-shading scene is precisely why. See PVsyst price and our PVsyst loss diagram guide.
SurgePV runs 8,760-hour shading and carries the same model into string design, the single-line diagram, and DWG export.
Aurora handles awkward historic roof planes better than anything else on the list, at a US price point.
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What an Italian Shading Deliverable Has to Contain
- Far-horizon profile covering terrain, on every site where hills or mountains are in view.
- Near-field 3D scene covering the building’s real geometry, adjacent structures, and vegetation.
- Hourly shading loss with monthly breakdown, winter months explicit.
- Terrain and near-field losses reported separately, because the remedies are different.
- Diffuse fraction stated for the site’s region, since north and south differ materially.
- Per-string loss table identifying compromised positions on irregular roof planes.
- Inter-row pitch derivation for the site’s own latitude rather than a national default.
Item 4 matters commercially. A near-field loss can often be fixed by moving modules or removing an obstruction. A terrain loss cannot be fixed at all, and telling the two apart is what lets a customer decide whether the site is worth it.
Pricing in Euro
| Stack | USD per year | Approx. EUR at 0.92 | Covers |
|---|---|---|---|
| PVsyst | ~$500 | ~€460 | Terrain and detailed shading |
| PV*SOL premium | Quoted in EUR | ~€1,000+ | 3D shading plus workflow |
| HelioScope | ~$1,188 | ~€1,093 | Commercial layout and shading |
| SurgePV | $1,299 to $1,899 | ~€1,195 to €1,747 | Shading plus full design |
| Aurora | $1,908 to $3,108 | ~€1,755 to €2,859 | Historic roof geometry plus proposal |
Exchange rate is illustrative.
What Most Italian Installers Get Wrong
They treat the horizon as flat in a country that mostly is not.
On a valley site in the north, the ridge can take the first and last hours of every winter day. That loss is larger than every chimney and neighbour on the roof combined, it is completely invisible to a model of the building, and it is unfixable, which makes knowing about it before the sale the difference between a satisfied customer and a dispute. Capturing the profile takes an instrument and twenty minutes, or an elevation dataset and less.
The second mistake is applying one national rule of thumb across ten degrees of latitude. Inter-row pitch derived for Lombardy over-spaces a Sicilian array and pitch derived for Sicily shades a Lombard one through the entire winter. Derive it from the site.
When Software Is Not the Answer
Italian historic buildings frequently need structural assessment and heritage coordination before any layout is meaningful, and neither is a modelling output.
Our solar civil and structural engineering team produces those assessments with calculations delivered as STAAD Pro report calculations, and solar rooftop detailed engineering design covers the construction pack. See the sample design pack or talk to our team.
Conclusion
- Survey the terrain horizon. On northern and central Italian sites it is often the largest loss and it cannot be fixed.
- Separate terrain from near-field losses. One is remediable and the other is not.
- Derive pitch for the site’s latitude. Ten degrees of range makes any national default wrong somewhere.
In this country series: solar software in Italy, best solar design software in Italy, best solar proposal software in Italy, Pvcase review. Tool deep dives: Pvsyst review, Helioscope review.
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Disclosure and accuracy note
Commercial relationship. Heaven Designs and SurgePV are part of the same group. Treat our recommendation of SurgePV as a vendor making its own case, not an independent verdict. We have tried to describe every other product fairly, and to say plainly where a competitor is the better choice.
Pricing. All prices are indicative, compiled from public sources when this page was written. They vary by tier, region, contract term and exchange rate, and change without notice. Several vendors quote rather than publish, and some price in currencies other than the US dollar, so a converted figure moves with the exchange rate. Confirm current pricing with the vendor before you decide anything.
Trademarks and corrections. All product names and trademarks belong to their respective owners, and are used here for identification and comparison only. Their use does not imply affiliation with or endorsement by those companies. If anything here is out of date or wrong, tell us and we will correct it.
FAQ
What is the best solar shading analysis software in Italy? PVsyst, because it takes a far-horizon terrain profile and a near-field 3D scene as separate explicit inputs. SurgePV where the same licence also has to produce the layout and single-line diagram, and Aurora for the most awkward historic roof geometry.
Why does terrain matter in Italy? Because much of the north and centre is mountainous or hilly. A ridge can remove the first and last hours of every winter day, and that loss is invisible to any model of the building alone.
Do historic roofs need special handling? Yes. Irregular planes, varying pitches, and very close neighbours defeat automated roof detection and rectangle-based layout tools. A manually built 3D scene is usually the only reliable approach.
Does shading cost the same across Italy? No. Southern skies are clear, so a shadow removes close to its full geometric value. Northern sites, particularly in the Po valley, have a higher diffuse fraction and softer losses.
Does CEI 0-21 specify a shading method? No. It governs low-voltage grid connection, with CEI 0-16 covering medium voltage. The shading method is an engineering choice.
How much does solar shading analysis software cost in Italy? From roughly €460 per year for PVsyst alone to €2,859 for Aurora’s higher tiers. Full math is in our solar design software pricing breakdown.
Related: the wider tool decision is in best solar design software in Italy, and the method in how to do shadow analysis for solar rooftop projects.
