Solar Shading Analysis Software Netherlands: Top 10

If you are choosing solar shading analysis software Netherlands installers actually use in 2026, the first thing to accept is that the Dutch shading problem is not the one most tools were built for. Imported platforms are optimised for a pitched roof with a chimney and a tree on it. The Dutch rooftop market is dominated by flat commercial roofs carrying ballasted east-west blocks, where the thing casting the shadow is not a chimney but the next row of your own array. That is a genuinely different modelling job, and a tool that handles near-object shading beautifully can still get an east-west distributiecentrum roof wrong. The platform that wins our 2026 bench is SurgePV at roughly €1,180 (US$1,299) per user per year on the 5-User Team plan, with concrete weaknesses named below. This ranking covers ten shading and irradiance tools priced in euros, including measurement instruments and horizon workflows rather than only design suites.

Direct answer. The best solar shading analysis software for the Netherlands in 2026 is SurgePV, at about €1,180 per user per year on the 5-User Team plan, because it models flat-roof east-west row geometry with mutual inter-row shading natively, runs 8,760 hourly simulation points at module level with bypass-diode physics on every paid plan, and uses a Perez anisotropic sky model that matters more here than almost anywhere because roughly half of Dutch annual irradiance is diffuse. PVsyst remains the format a Dutch bank asks for by name, and Solar Monkey from Delft remains faster on a straightforward residential roof.

This guide is written for installateurs, adviesbureaus and EPC design teams whose opbrengst numbers get challenged. It sits under our global pillar on solar shading analysis software and beside the wider solar design software Netherlands ranking, which covers the full design and tariff workflow rather than shading alone.

Why Dutch Shading Is an Inter-Row Problem, Not a Chimney Problem

Dutch commercial roofs are flat, wind exposed and frequently weight limited, and the standard answer on them is a ballasted east-west block: two rows back to back at 10 to 15 degrees, one face east, one face west, repeated across the roof. That configuration packs far more kWp onto the same area than south-facing rows, flattens the daily generation curve, and cuts ballast because the blocks shelter each other aerodynamically. It is the default, not the exception.

It also changes the shading question completely. On a south-facing array the ridge lines run east to west, and the binding constraint is the low winter sun at solar noon shading the row behind. On an east-west array the ridge lines run north to south, so the midday southern sun runs parallel to the rows and casts almost no inter-row shadow at all. The December-noon constraint that dictates GCR in a south-facing field simply does not bind here, which is exactly why GCR on a Dutch east-west roof runs above 0.7 while a south-facing equivalent is stuck near 0.35.

What you pay instead is a shading event that happens on every clear day of the year, at low sun elevation, from the east in the morning and the west in the evening. The west-facing back of one block shades the bottom edge of the east-facing face of the next block until the sun climbs high enough to clear the ridge. That is a different loss profile: small in magnitude per event, frequent in occurrence, concentrated at exactly the hours a flattened generation curve was supposed to protect. Averaging it away is easy and wrong.

Key takeaway. A shading engine that only models near-object geometry from chimneys, dakramen and neighbouring gables will produce a defensible number on a Dutch terraced house and a misleading one on a 600 kWp logistics roof. The Dutch buying decision turns on whether the tool models mutual inter-row shading between east-west blocks as real geometry, or treats the roof as one big tilted plane.

The Oost-West Arithmetic: Tilt, Gap and the Clearing Angle

Work the geometry once and the tool requirements become obvious. Take a common module 1.134 m across, mounted in horizontal orientation, in a back-to-back east-west block.

At 10 degrees tilt, the ridge stands 1.134 times the sine of 10 degrees above the low edge, which is 0.197 m. Each face projects 1.134 times the cosine of 10 degrees, which is 1.117 m, onto the roof. Put a 0.3 m maintenance gap between blocks, and the horizontal distance from one block’s ridge to the low edge of the next block’s east-facing face is 1.117 plus 0.3, which is 1.417 m. The morning shadow of that ridge reaches the next low edge when the tangent of the solar elevation equals 0.197 divided by 1.417, or 0.139. That is a solar elevation of 7.9 degrees. Above that, the next row is clear.

At 15 degrees tilt, ridge height rises to 0.293 m and the face projection falls to 1.095 m, so the distance is 1.395 m and the tangent is 0.293 divided by 1.395, which is 0.210. That is a clearing elevation of 11.9 degrees.

Four degrees of solar elevation sounds trivial. It is not, because near sunrise the sun climbs slowly. At Dutch latitudes on a clear day the difference between a clearing angle of 8 degrees and one of 12 degrees is roughly half an hour of partially shaded east faces every morning, repeated 365 times, and mirrored again in the evening on the west faces. That is why a tool that lets you sweep tilt and gap together and reports annual energy rather than a single peak-day figure earns its money on Dutch roofs, and why a tool without native east-west block geometry cannot answer the question at all.

Note what does not appear in this arithmetic: the 21 December noon sun. Amsterdam at 52.37 degrees north gets a solar noon elevation of 90 minus 52.37 minus 23.44, which is 14.2 degrees, essentially identical to Berlin. On a south-facing array that number would dominate everything. On an east-west block, with ridges running north to south, the noon sun passes along the rows rather than across them, so the December-noon constraint is close to irrelevant. Two markets at the same latitude, two completely different binding constraints, because the roof stock is different.

Why the Diffuse Sky Changes the Answer in the Netherlands

The Dutch maritime climate produces a lot of cloud, and cloud converts direct beam radiation into diffuse radiation. Roughly half of annual global horizontal irradiance at a Dutch site arrives as diffuse light rather than direct beam, which is materially higher than a continental or Mediterranean site. Our glossary entry on diffuse horizontal irradiance sets out the measurement.

That matters for shading because a shaded module is not a dark module. It has lost the direct beam but still sees most of the sky dome, so its output depends almost entirely on how well the tool models diffuse light. An isotropic sky model assumes diffuse radiation arrives uniformly from every part of the hemisphere. It does not. Diffuse light concentrates in a bright circumsolar region around the sun and in a horizon brightening band, which is what the Perez and Hay-Davies anisotropic models exist to represent.

The practical consequence on a Dutch east-west roof is direct. A row whose lower edge is beam-shaded at 6 degrees solar elevation is also losing part of the circumsolar diffuse component, because the sun’s own neighbourhood in the sky is behind the row in front. An isotropic model will not see that, so it overstates the shaded row’s output at exactly the hours the shading occurs. On a partly shaded array the error runs in both directions depending on geometry, which is worse than a consistent bias because you cannot correct for it with a fudge factor.

What the End of Saldering Does to a Wrong Shading Number

The salderingsregeling ends on 1 January 2027, in one step rather than a taper, per the Rijksoverheid. After that date exported kWh are paid at a supplier-set redelivery rate with a legal floor of 50 percent of the net supply rate until 2030, and the energy tax refund disappears. Self-consumption becomes worth roughly twice what export is worth.

That reprices shading error. Under saldering, a kWh lost to shading and a kWh exported were worth almost the same thing, so an optimistic shading estimate showed up as a small annual shortfall the customer rarely noticed. After 2027 the kWh you lose are disproportionately the ones that would have been self-consumed during working hours, which are the expensive ones. The same modelling error now produces a bigger cash gap and a customer who can see it on a monthly bill.

It also changes what an east-west decision is for. East-west flattens the generation curve, raising the fraction of production that is consumed on site rather than exported. That was a modest packing argument under saldering. It is a primary financial argument after 2027, which means the inter-row shading tradeoff that decides tilt and gap is now a financial calculation rather than a purely engineering one. Your shading tool has to hand its hourly output to a financial model that knows the difference between a self-consumed and an exported kWh, or you are doing the optimisation blind.

Get your sizing sanity-checked. For a fast independent second opinion on system size and payback before you finalise an east-west layout, run the numbers through our free solar calculator or talk to our engineering team.

Top 10 Shading Analysis Tools in the Netherlands Compared

Pricing is 2026, annualised, with dollar-denominated products converted at roughly €0.91 per US dollar. Treat converted figures as indicative and confirm with the vendor.

The honest read: positions 1 to 4 are the real Dutch choice. Positions 6, 9 and 10 are measurement inputs rather than competitors, and a serious shading practice runs at least one of them alongside its main engine.

1. SurgePV

What it does best. For Dutch work the reason to look is flat-roof geometry. East-west back-to-back blocks are a native layout object rather than a workaround, so tilt, row gap and block spacing are parameters you sweep, and the 8,760-hour simulation reports mutual inter-row shading between blocks as real geometry at module level with bypass-diode physics. That means you can see what moving from 15 degrees to 10 degrees actually buys in annual kWh instead of arguing about it. The sky model is Perez anisotropic, which matters on a roughly 50 percent diffuse Dutch sky. The output feeds string and MPPT grouping directly, so the east faces and west faces do not end up on the same input, and it carries into the NEN 1010 part 712 labelled single-line diagram and the Dutch offerte without a re-import. Export capacity can be capped so a congested netbeheerder connection shows the clipping alongside the shading loss.

Pricing. €1,180 (US$1,299) per user per year on the 5-User Team plan, so €5,900 for five seats. Individual seats about €1,730 per year. Free trial, no credit card.

Who it suits. Installateurs and EPCs doing five or more designs a month who sell flat-roof C&I alongside residential.

Honest limitations. Four concrete ones. It cannot import a measured horizon file from a Solmetric SunEye or a fisheye photograph, so in a dense Amsterdam courtyard or a binnenstad site with tall neighbours you are working from modelled geometry rather than a measurement taken on the roof. It has no drone photogrammetry ingest, so a mature canopy is modelled from satellite rather than a Scanifly point cloud. Its montagesysteem database is thin on the specific Dutch ballast systems local suppliers stock, which matters here more than elsewhere because a shading-driven change to row pitch immediately changes the NEN 7250 ballast plan, and that recheck stays manual. And on a financed project a Dutch bank or an investor’s technical adviser has never seen its report format, where a PVsyst near-shading study needs no introduction.

Book a SurgePV demo and bring a real east-west roof with a known problem row, because a clean roof tells you nothing about a shading engine.

2. PVsyst

What it does best. PVsyst is the reference, and its treatment of shading is the specific reason. It separates near shading from the far horizon, and critically it separates the geometric irradiance loss from the electrical shading loss caused by string mismatch and bypass diodes, then documents both in a loss diagram a reviewer can audit line by line. For unlimited-sheds and repeated-row geometry it has a dedicated model that is well suited to east-west blocks. On bankability it beats SurgePV and we are not going to pretend otherwise. Heaven Designs published a guide to reading a PVsyst loss diagram if you have to defend one.

Pricing. PVsyst bills in Swiss francs and it is an annual subscription rather than a perpetual licence: CHF 700 per user per year for Professional, CHF 420 Education, CHF 560 Training and Research, CHF 25 Student and Classroom, and CHF 3,000 for PVsystCLI, with group discounts of 5 to 20 percent by quantity. Five Professional seats are CHF 3,500 a year, which is cheaper than five SurgePV seats at US$6,495. We would rather say that than dress it up.

Who it suits. Technical due diligence, SDE++ backed projects with external finance, zonneweide developers.

Honest limitations. Windows desktop, a steep learning curve, slow manual scene building, no design workflow in the installateur sense, no proposals and no Dutch tariff logic at all. See our PVsyst alternative guide and the HelioScope versus PVsyst head to head.

3. HelioScope

What it does best. HelioScope is genuinely good at the thing Dutch C&I needs, which is module-level simulation across a large repeating array with mutual row shading and a clean, exportable loss tree. On a 600 kWp distributiecentrum roof with dozens of east-west blocks it produces a defensible number quickly, and Dutch independent engineers accept the format without argument.

Pricing. HelioScope prices in US dollars: Basic US$159 a month or US$1,620 a year, Pro US$259 a month or US$2,640 a year, each covering one user and ten projects a month, with DC design capped at 1.25 MW on Basic and 5 MW on Pro. At €0.91 per dollar that is about €145 and €236 a month, and five Basic seats are US$8,100 a year.

Who it suits. Adviesbureaus and C&I-only teams whose deliverable is an opbrengstprognose.

Honest limitations. No Dutch regulatory or tariff layer, no NEN labelling, no saldering logic, no satellite 3D roof capture and weak proposal output that forces a second licence. Near-object modelling on complex pitched roofs is coarser than PV*SOL. Read our HelioScope alternative guide first.

4. Solar Monkey

What it does best. Solar Monkey was built in Delft for Dutch installers and it shows in the shading defaults. It pulls Dutch address and building data, derives the roof from aerial imagery, and runs shading against surrounding buildings and trees from that data automatically, so a residential shading answer arrives in minutes rather than a manual tracing session. It carries into monitoring after handover with a yield guarantee attached, which means its shading model is being validated against measured production on real Dutch roofs continuously. That feedback loop is a real advantage and nothing on this list matches it in the Benelux.

Pricing. Solar Monkey does not sell seats. It publishes a package price of EUR 525 a month which includes 50 projects, with API integration a further EUR 95 a month, and it discounts 5 percent for quarterly payment and 10 percent for annual. There is a 14-day trial. The rate charged for projects beyond the included 50 is not publicly listed, so if your volume runs past that, ask before you sign. Note that this is a firm-level package rather than a per-user cost, so for a five-person residential team it works out well below five seats of anything else on this page, including ours at US$6,495. A merger with Eturnity was announced on 25 March 2026.

Who it suits. High-volume Dutch residential installers, and firms who want design and post-installation monitoring from one vendor.

Honest limitations. It is residential-first, and the flat-roof east-west C&I case is where that shows. On a 500 kWp roof with an export cap its engineering depth and reporting are thinner than HelioScope or PVsyst, and lenders do not treat its output as a bankable yield report. There is no measured-horizon or drone ingest, no ground-mount capability, and its market is essentially the Benelux, so a firm designing in Germany or the UK needs a second tool.

5. PV*SOL premium

What it does best. The animated 3D shading walkthrough is the best customer-facing shading explanation in any tool here, and on the dormers, hips and close neighbours of Dutch rijtjeshuizen it fights you less than the cloud tools. The European component database is deep on hardware Dutch wholesalers actually stock.

Pricing. PVSOL premium is a named-user subscription, not a perpetual licence: EUR 845 per named user per year plus VAT, with standard PVSOL at EUR 585. Five named users are EUR 4,225 a year, which is less than five SurgePV seats. Licences bought before 19 November 2024 remain usable indefinitely, but maintenance renewals on them ended on 1 October 2024.

Who it suits. Pitched-roof residential selling and established adviesbureaus.

Honest limitations. Windows desktop, no live collaboration, no satellite roof capture, and shading output that does not flow into a sendable offerte. Its financial module is built around German feed-in logic, so the saldering phase-out has to be rebuilt elsewhere. Our PV*SOL alternative guide covers the tradeoff.

6. Scanifly

What it does best. Drone photogrammetry turns the actual site, trees included, into a measured 3D model, then runs shading against that geometry rather than an operator’s guess at tree height. On an older Dutch neighbourhood with mature street trees close to the roofline, that removes the single largest source of residential shading error.

Pricing. Scanifly does not publish pricing. There is no per-seat rate and no per-project rate on its site, so the only reliable number is a quote you obtain yourself, and any figure circulating in software directories is unverified. See our Scanifly pricing breakdown for what is and is not knowable.

Who it suits. Firms that already fly drones and whose shading disputes come down to vegetation.

Honest limitations. You need a drone, a pilot and EU drone rule compliance, which in dense Dutch urban areas is a real constraint. It is a capture and modelling tool, not a design suite or a financial model. Our Scanifly alternative piece covers the workflow question.

7. Polysun

What it does best. Vela Solaris models shading inside a coupled system, so the shaded array, the warmtepomp, the battery and the hot water all sit in one simulation. With the Dutch gas phase-out putting a heat pump into most renovation conversations, seeing how shading loss moves the self-consumption fraction of a coupled system is genuinely useful after 2027.

Pricing. Vela Solaris does not publish Polysun pricing. It sells either a one-off purchase plus an annual service subscription, or a lease with a twelve-month minimum, both quoted on request. A EUR 699 figure circulating in software directories traces back to a 2013 price list and should not be treated as current.

Who it suits. Adviesbureaus doing renovation and sector-coupling work.

Honest limitations. Shading is a component rather than the focus. The 3D obstruction editor is weaker than PV*SOL’s, there is no customer-facing animation, and the flat-roof east-west row optimisation is not its strength.

8. Aurora Solar

What it does best. Strong residential shade rendering and mature roof plane detection, with a polished customer-facing presentation.

Pricing. Aurora publishes US dollar prices: Basic US$135 per user per month billed annually, US$159 monthly, and Premium US$220 billed annually, US$259 monthly, each covering one user and 50 projects a month. At €0.91 per dollar that is about €123 and €200. Five Premium seats are US$13,200 a year and five Basic seats US$8,100. The old Grow, Scale and Run tiers no longer exist. Stated plainly: Aurora Basic at US$1,620 a year undercuts a SurgePV Individual seat at US$1,899.

Who it suits. Multinational installers extending an existing Aurora process into the Netherlands.

Honest limitations. LIDAR modelling and bankable shade reports sit on Premium rather than Basic, and plan sets are a separately priced service rather than a plan inclusion. LIDAR-backed irradiance coverage is far better in North America than in the Netherlands, the Dutch tariff and regulatory layer is close to empty, and per-seat pricing scales badly. See our Aurora Solar alternative comparison.

9. PVGIS and Meteonorm Horizon Import

What it does best. These are inputs rather than design tools. The European Commission’s Joint Research Centre publishes PVGIS free, including a terrain horizon profile and a diffuse fraction for any Dutch coordinate, and it imports into PVsyst or PV*SOL directly. Meteonorm sells a commercial dataset with finer irradiance modelling. In a country with essentially no terrain, the value here is less about horizon and more about checking that whatever irradiance dataset your engine uses agrees with an independent Dutch source before you defend a number.

Pricing. PVGIS is free. Meteonorm publishes its own price in Swiss francs: CHF 675 for a first licence and CHF 350 for each additional licence, excluding VAT, bought once per software version rather than as an annual subscription.

Who it suits. Anyone whose yield figure is being challenged and who needs an independent irradiance reference.

Honest limitations. No knowledge of the chimney, the dakraam or the row in front. It complements a near-shading engine rather than replacing it.

10. Solmetric SunEye 210

What it does best. A handheld fisheye instrument that photographs the whole sky dome from a specific point on the roof, overlays the annual sun path and returns a measured monthly solar access percentage. In a dense Amsterdam or Utrecht binnenstad courtyard surrounded by four storey buildings, a measurement settles an argument that a satellite model cannot.

Pricing. US$2,195 for the base North American kit, about €2,000 at €0.91 per dollar, bought new from Solmetric. A lifetime PV Designer licence is included in that price. It was out of stock as of 2 August 2026 with a stated 10 to 12 week lead time.

Who it suits. Audit teams and firms handling shading disputes with a customer or a neighbour.

Honest limitations. It is a current product rather than a discontinued one, and Solmetric has been a Fluke company since the acquisition announced on 12 September 2023, but the lead time means you cannot buy one mid-dispute. It measures one point, so a large roof needs several readings, and it returns solar access rather than energy, so the result still has to be carried into a simulation.

The 5-Point Oost-West Shading Test

This is the framework we run on our own solar EPC work before a Dutch flat-roof design leaves the office. Any tool you are evaluating should pass all five with a real project loaded.

1. Is an east-west block a first-class layout object? You should be able to set tilt, row gap and block spacing and have the engine treat the geometry as repeated rows, not as one averaged tilted plane. If the tool asks you to draw each row by hand, it will not survive a 600 kWp roof.
2. Can you sweep tilt and gap and read annual kWh? The 10 degree versus 15 degree decision is worth real money, and it is only answerable as an annual figure. A peak-day shadow diagram does not settle it.
3. Is the electrical shading loss separated from the geometric one? Geometric shade is the shadow. Electrical loss is what the bypass diodes and string mismatch do with it, and it is usually the larger number. Our shading loss glossary entry sets out why.
4. Is the sky model anisotropic? With roughly half of Dutch annual irradiance arriving as diffuse light, an isotropic assumption misprices exactly the partly shaded rows you are trying to value. Perez or Hay-Davies, not isotropic.
5. Does the hourly output reach a financial model that knows about self-consumption? After 1 January 2027 a self-consumed kWh is worth roughly twice an exported one, so shading loss at 11am and shading loss at 6pm are not the same loss. If the shading result lands in a spreadsheet as one annual percentage, that distinction is gone.

Mistakes Dutch Installateurs Make in Shading Analysis

1. 1
   Modelling a flat roof as one tilted plane. An east-west field averaged into a single surface loses the entire inter-row story, and the resulting number is optimistic in exactly the morning and evening hours that now matter most for self-consumption.
2. 2
   Choosing tilt from a ballast table rather than a shading run. Fifteen degrees is a common default because it suits a mounting system, but it costs about four degrees of clearing elevation against ten degrees, every morning of the year. Decide it with numbers.
3. 3
   Putting east and west faces on the same MPPT. The whole point of an east-west array is that the two faces peak at different times. Sharing an input throws that away and turns every morning shading event into a loss on the west faces too.
4. 4
   Using an isotropic sky model on a maritime sky. Around half of Dutch annual irradiance is diffuse. An isotropic assumption misprices partly shaded rows in both directions, which is worse than a consistent bias because you cannot correct it.
5. 5
   Quoting a shading loss as one annual percentage after 2027. Once saldering ends, when a kWh is lost matters as much as how many. An annual percentage hides the hour, and the hour is where the money is.

The wider set of process failures is covered in our writeup on common mistakes EPC companies make in rooftop solar.

Should a Dutch Installer Standardise on SurgePV for Shading?

Verdict. For a Dutch firm whose volume is flat-roof east-west C&I alongside residential, SurgePV wins because it treats the row geometry as the real problem and carries the hourly result into a financial model that survives 1 January 2027. For a residential-only installer already closing deals in Solar Monkey with monitoring attached, staying put is the rational choice, and on a financed project PVsyst keeps its seat regardless.

How Heaven Green Energy and SurgePV Help Dutch Teams

Heaven Green Energy has delivered more than 10,000 solar installations, and our engineering group builds the software our own designers use. SurgePV came out of that, written by people who had to defend an opbrengst figure to a customer holding last month’s bill. For Dutch teams the entry points are:

• Shadow analysis for 8,760-hour module-level inter-row and near-object shading.
• Ballasted versus penetrating rooftop mounting when a row-pitch change puts the membrane warranty in play.
• Structural and civil engineering for the NEN 7250 wind and ballast recheck a shading optimisation triggers.
• Inverter clipping explained when a capped netbeheerder connection sits on top of the shading loss.

If you also run projects outside the Netherlands, our commercial solar and industrial solar pages set out how the same stack carries across markets. Wider context sits with IRENA country profiles, the IEA renewables tracker and Solar Magazine for Dutch sector news.

Related Shading and Design Software Guides

• Solar Shading Analysis Software: The Global Guide
• Solar Shading Analysis Software in Germany
• Solar Design Software Netherlands: Top 10 Ranked
• Best Solar Proposal Software in the Netherlands
• Best Solar Software in the Netherlands: The Full Stack
• Best Solar Design Software: The Global Ranking
• PV Yield Simulation Software Compared
• Commercial Solar Design Software Compared

Shading Analysis in Nearby Markets

The Netherlands shares German winter sun geometry and British maritime sky conditions, and the two guides below cover each side.

• Best solar shading analysis software in the UK
• Solar shading analysis software: the global guide

Frequently Asked Questions

What is the best solar shading analysis software for the Netherlands in 2026?

SurgePV ranks first, at about €1,180 per user per year on the 5-User Team plan, because it treats flat-roof east-west blocks as native geometry with mutual inter-row shading, runs 8,760 hourly points at module level with bypass-diode physics on every paid plan, and uses a Perez anisotropic sky model that matters on a roughly 50 percent diffuse Dutch sky. PVsyst ranks second as the format a bank asks for by name, HelioScope third on large flat roofs, and Solar Monkey fourth and faster on straightforward residential work.

Why is inter-row shading the main Dutch shading problem?

Because the Dutch rooftop market is dominated by flat commercial roofs carrying ballasted east-west blocks, so the object casting the shadow is usually the previous row of the same array rather than a chimney. East-west blocks run their ridge lines north to south, which means the low December noon sun passes along the rows instead of across them and the winter-noon constraint that dictates row pitch on south-facing arrays does not bind. The loss moves to low-sun morning and evening hours instead, on every clear day of the year.

What tilt should a Dutch east-west array use?

Ten to fifteen degrees is the normal range and the choice is a real tradeoff. With a 1.134 m module in horizontal orientation and a 0.3 m gap between blocks, a 10 degree array clears inter-row shading once the sun passes about 7.9 degrees elevation, while a 15 degree array needs about 11.9 degrees. Higher tilt gains peak-hour output and costs morning and evening hours, and it also changes wind loading and ballast under NEN 7250. Settle it with an annual kWh sweep, not a default.

How high does the sun get in the Netherlands in winter?

Amsterdam sits at about 52.37 degrees north, so solar noon on 21 December reaches 90 minus 52.37 minus the earth’s 23.44 degree axial tilt, which is roughly 14.2 degrees. Every object then casts a shadow about four times its own height. On a south-facing array that constraint dominates row spacing. On an east-west array it largely does not, because the rows run north to south and the southern noon sun runs parallel to them.

Does the salderingsregeling ending change shading analysis?

Yes, indirectly but significantly. From 1 January 2027 export is paid at a supplier-set redelivery rate with a legal floor of 50 percent of the net supply rate until 2030, and the energy tax refund disappears, so a self-consumed kWh is worth roughly twice an exported one. Shading loss is therefore no longer one annual percentage. Loss at 11am on a working day costs more than the same loss at 6pm, so the hourly shading output has to reach a financial model that distinguishes the two.

Is a shading report legally required in the Netherlands?

No. There is no Dutch equivalent of the UK MCS Standard Estimation Method shading factor and no mandated shading deliverable. What is regulated is the installation under NEN 1010 part 712 and the building side under NEN 7250, which covers wind loading and building physics on flat roofs. Shading analysis is commercial and contractual practice rather than compliance, so sell it on accuracy rather than on an invented requirement.

Why does a high diffuse fraction change the shading result?

Roughly half of Dutch annual global horizontal irradiance arrives as diffuse light because of maritime cloud cover. A shaded module has lost the direct beam but still sees most of the sky dome, so its output depends almost entirely on how the diffuse component is modelled. An isotropic model assumes diffuse light arrives uniformly from the whole hemisphere, when it actually concentrates in a circumsolar region and a horizon band. That misprices partly shaded rows, in either direction depending on geometry.

What is SurgePV’s biggest weakness for Dutch shading work?

Three concrete ones. It cannot import a measured horizon file from a Solmetric SunEye or a fisheye photograph, which matters in a dense binnenstad courtyard. It has no drone photogrammetry ingest, so mature street trees are modelled from satellite rather than a Scanifly point cloud. And its montagesysteem database is thin on Dutch ballast systems, so a shading-driven change to row pitch still forces a manual NEN 7250 ballast recheck. On financed work a Dutch bank has also never seen its report format, where PVsyst needs no introduction.