Solar panels are the most popular sustainability measure in the Netherlands and, for many homeowners, the first step towards a lower energy bill and a better energy label. The technology is mature and the installation is done in a day, but that does not make it a job to outsource lightly. A roof that really should have been replaced first, an inverter that does not suit the roof, a consumer unit without a spare circuit, a forgotten registration with the grid operator or a leak at a roof penetration for which nobody wants to be responsible: these are the complaints that come back after installation. This article walks through the whole route, from the suitability of the roof to the handover, and explains who does which part of the work. For the wider options and schemes for making your home more sustainable, read Sustainable renovation: grants and options.
Is your roof suitable?
Not every roof is a good solar roof, and a bad start on the roof cannot be put right later. Assess the following points, preferably together with the installer and, if you have doubts about the roof covering, a roofer:
- Orientation. A south-facing roof slope gives the highest yield, but south-east and south-west are hardly any worse. East and west give less per panel, but spread production over the day, which is actually favourable once net metering ends because you use more of your own generation directly. A purely north-facing roof slope is rarely recommended.
- Pitch. For the Netherlands, the optimum angle is around thirty-five degrees; anything between roughly twenty and fifty degrees yields hardly any less, and flatter or steeper roofs also score better than is often thought.
- Shade. A chimney, dormer, tree or taller neighbouring building that casts shade for part of the day reduces the yield of the whole string system. Ask the installer for a shading analysis and, if there is shade, consider micro-inverters or optimisers (see below).
- Load-bearing capacity. Panels, the mounting system and, on a flat roof, the ballast put extra weight on the structure. On a sound pitched roof with tiles this is rarely a problem; with a flat roof, a lightweight structure, an old roof or a roof that is already sagging, a structural assessment is wise. The owner remains responsible for structural safety, even if no permit is required.
- Condition of the roof covering. This is the point that is skipped most often. Solar panels last twenty-five years or more; a bitumen roof or tiled roof that will need replacing within ten years should be renewed first. Removing panels from a roof and putting them back for a roof renovation is costly and often comes at the expense of guarantees. Have a roofer assess the roof covering, the gutters and the flashings before the panels are ordered, and where possible combine roof insulation and roof renewal with the installation.
- Asbestos. Asbestos has been banned since 1 July 1993, so corrugated sheets or roof boarding in homes built before 1994 may contain asbestos. Drilling or screwing into it is not permitted and installers will not mount panels on it; the roof must first be cleaned up by a certified company.
Permit: when you do and when you don't need one
Under the Omgevingswet (the Dutch Environment and Planning Act), solar panels on the roof of a home are as a rule permit-free, both for the technical building activity and for the omgevingsplan (environment plan) activity. The Besluit bouwwerken leefomgeving (Bbl, the Dutch Building Decree) designates solar panels and solar collectors on a roof as permit-free nationally, subject to conditions: on a pitched roof the panels lie within the roof surface, in or directly on the roof and at the same pitch as the roof; on a flat roof they stay at a distance from the roof edge at least equal to the height of the panel; and the inverter or storage tank, if it does not form a single unit with the panel, is inside a building (article 2.29, under d, Bbl; the technical side is exempted via article 2.27, under k). A national permit-free rule takes precedence over your municipality's omgevingsplan; the municipality therefore cannot make these panels subject to a permit after all via the omgevingsplan.
There are exceptions to this that you must take seriously:
- Listed buildings. On a national, provincial or municipal listed building (including one with provisional protection), solar panels are not permit-free; you need an omgevingsvergunning (environmental permit) and the municipality assesses the application against the heritage value. Panels at the back, out of sight, stand a better chance.
- Nationally protected townscape or village view. In a rijksbeschermd stads- of dorpsgezicht (nationally protected townscape or village view), panels are only permit-free on a rear roof slope that does not face publicly accessible areas (article 2.30 Bbl); on front and side roof slopes, or on a rear roof slope facing a public path or water, a permit is required.
- Panels in a different arrangement. Panels on a frame at a different angle from the roof slope on a pitched roof, panels that project beyond the roof edge, or panels on a carport, boundary partition or in the garden are not covered by the standard exemption and require a check in the Omgevingsloket (the government's online permit portal).
- Welstand (aesthetic control). Municipalities can set rules in their omgevingsplan or welstandsnota (design policy document) on the appearance of panels at the front; for panels that are permit-free nationally, only retrospective aesthetic enforcement remains, but in protected areas the appearance does carry weight.
Always do the permit check in the Omgevingsloket and keep the outcome. If you live in an apartment, the roof is jointly owned and you need permission from the vereniging van eigenaren (VvE, owners' association), usually via a resolution of the owners' meeting; many VvEs choose to install the panels collectively. Arrange this before you commit to an installer.
Pitched roof or flat roof: mounting, ballast and east-west
On a pitched roof, the panels are fixed on a rail system with hooks to the tile battens or with screws to the structure, at the same angle as the roof. The roof covering remains intact, but tiles sometimes need to be adjusted or replaced with lead flashing or a cable outlet tile. With in-roof systems, the panels replace part of the roof covering; that looks better, but requires watertightness to be guaranteed by the panels and flashing profiles, and is therefore even more of a job for a roofer.
On a flat roof, the roof covering is almost never drilled through. The panels stand in a frame held in place with ballast (paving slabs or blocks), so that wind cannot lift or shift the arrangement. The amount of ballast follows from a wind calculation per roof; the roof covering must be able to bear that weight and the point loads, and is protected with pedestals or rubber mats. A commonly used layout is the east-west arrangement: panels back to back at a low angle, which means more panels fit on the roof, the wind load is lower and the yield is spread over the day. South-facing arrangements at a steeper angle yield more per panel, but need more space between rows to avoid shading.
Fire safety and inspection
Fires caused by solar panels are rare, but when they do occur the cause is almost always a poorly made connector, damaged cabling or an incorrectly placed inverter. So ask explicitly about the working method: plugs of the same brand and type on both sides, cables that do not lie over sharp edges or in water, cables that are fixed on the roof rather than lying loose, and an inverter mounted on a non-combustible surface with enough ventilation and not in a cramped cupboard among combustible items. For the design and mounting of solar power systems on buildings there is the standard NEN 7250, which sets requirements for, among other things, structural integration, wind load, watertightness, fire safety and fixing. For commercial and larger (collective) installations, insurers increasingly require an independent Scope 12 inspection under the SCIOS scheme; for an ordinary home this is not mandatory and insurers do not usually ask for it, but do report the installation to your buildings insurer and ask whether any conditions apply. A tidy handover with an inspection report from the installer, including measurement of the string voltages and the insulation resistance, is a reasonable requirement for any home.
Inverter and home battery
Panels produce direct current (DC); the inverter converts this into alternating current (AC) that the home and the grid can use. There are three main variants:
| Type | How it works | Suits |
|---|---|---|
| String inverter | All panels in series (a string) on one central inverter; the weakest panel determines the yield of the string | An unobstructed roof slope without shade, one orientation; the simplest and most proven solution |
| Optimisers | A small controller per panel under the panel, combined with a central inverter; each panel delivers its own maximum | Partial shade, multiple orientations, monitoring per panel desired |
| Micro-inverters | One inverter per panel or per two panels on the roof; no high-voltage DC in the home | Small or complex roofs, shade, expandability, preference for low DC voltage |
An inverter usually has a shorter life than the panels and will need replacing once during the system's lifetime; bear that in mind when choosing a location that stays accessible. More and more inverters are hybrid and suitable for a home battery. A battery stores electricity generated during the day for the evening, increases self-consumption and becomes more attractive now that net metering stops on 1 January 2027 and energy suppliers charge for feeding electricity back. A battery is also an additional electrical installation with its own requirements for placement, ventilation and fire safety; have the location and the connection assessed by the same installer or electrician.
Net metering, feed-in charges, grid congestion and tax
The salderingsregeling (net metering scheme) means that the electricity you feed back into the grid is offset against the electricity you take from it, so that you only pay for net consumption. The Wet beëindiging salderingsregeling (the act ending net metering) has been passed and comes into force on 1 January 2027; net metering then stops in one go, without a phase-out. After that, you receive a reasonable payment from your energy supplier for electricity fed back, which until 1 January 2030 must amount to at least 50 percent of your bare supply tariff and may not be negative on average per month; the ACM (the Netherlands Authority for Consumers and Markets) supervises this. In addition, many energy suppliers already charge terugleverkosten (feed-in charges): a fixed monthly contribution or an amount per kilowatt hour fed back for customers with solar panels, because the peaks of solar power cost them money on the wholesale market. The ACM has investigated these charges several times and has not found them unreasonable; from 1 January 2027, suppliers must express feed-in charges for households as an amount per kilowatt hour fed back, so that contracts are easier to compare. The consequence for the design of your installation: the return shifts from "generate as much as possible" to "use as much as possible yourself". A somewhat smaller system, an east-west arrangement, smartly switching the heat pump, water heater and charging point to run during sunny hours, and possibly a home battery therefore become more important than under net metering.
You must register every generating installation with your grid operator via energieleveren.nl, the grid operators' national register for generating installations. The grid operator then knows what is connected to its grid and whether the meter is suitable; an old meter that runs backwards when feeding back is replaced. In many regions there is grid congestion: the grid is full. For homes with a small-consumer connection, this usually does not mean you are not allowed to install panels, but it does mean that on sunny afternoons the inverter may throttle back or switch off because of excessive grid voltage, so yield is lost. Ask the installer whether the inverter is set to gradual power reduction when grid voltage rises, which is possible with most inverters from after 2018; since 2024, grid operators no longer register individual reports of inverters cutting out, they reinforce neighbourhoods with structural voltage problems on their own initiative, and you have no right to compensation for lost yield.
Two tax points. Since 1 January 2023, the zero VAT rate has applied to the supply and installation of solar panels on or near homes, so you no longer have to reclaim the VAT separately from the Belastingdienst (the Dutch Tax Administration). The zero rate applies to the panels and what is needed to connect them (mounting materials, inverter, cabling, adapting the meter cupboard), but not to a home battery, a heat pump, a complete new consumer unit or integrated panels when buying a new-build home; on those you pay 21 percent. And the Investeringssubsidie duurzame energie en energiebesparing (ISDE, the Dutch investment grant for sustainable energy and energy saving) is intended for insulation and heat pumps, among other things, not for solar panels on homes; there is no national purchase grant for panels, but some municipalities and provinces have their own schemes or loans, and an Energiebespaarlening (energy-saving loan) is available via the Nationaal Warmtefonds (the Dutch national heat fund). An overview of what is subsidised can be found in the article on sustainable renovation.
Who does what: installer, electrician and roofer
With a typical installation by a specialist solar panel company, most of the work comes from a single source, but it is useful to understand which disciplines are involved and who is responsible for what.
- The installer or electrician designs the system (number of panels, string layout, inverter), lays the panels and the DC cabling on the roof, fits the inverter, runs the AC cable to the meter cupboard and connects it to a dedicated circuit in the consumer unit with the correct protection. They test the installation, configure the inverter and set up the monitoring. If the unit has no spare circuit, no residual current protection suitable for an inverter, or a three-phase connection is needed, the consumer unit must be adapted first; when that is necessary and what it involves is explained in Replacing or extending the consumer unit. This electrical part is work for an electrician or an installer with an electrical accreditation, not for a fitter who only lays panels.
- The roofer is responsible for everything that affects the watertightness of the roof: the penetrations for cables through the roof covering or the tiles, repairing or replacing tiles, lead and bitumen, assessing whether the roof covering can bear the ballast and being walked on and, with an in-roof system or a roof renovation, the entire roof surface. On a simple tiled roof, the installer usually does the roofing work themselves; with a flat roof with older bitumen, an in-roof system or a roof that needs renewing anyway, a roofer should be involved. Safety on the roof, with edge protection or fall arrest, is also the responsibility of whoever carries out the roofing work.
- The grid operator does nothing to your installation, but records the registration, replaces the meter if necessary and monitors the grid voltage.
- You as the owner arrange the VvE permission, the permit check, notifying your buildings insurer, the registration with the grid operator (unless the installer demonstrably does it for you) and an energy contract in which feeding back is properly arranged.
Who is responsible for a leak after installation? Legally, it is whoever carried out the work on the roof and did so defectively: the installer who fitted the hooks or made the penetration, or the roofer who renewed the roof surface. In practice, disputes arise if both have been on the roof, or if the roof was already old and the installer did not report it. Prevent that: have the condition of the roof recorded before installation (photos and a brief assessment), preferably choose one contracting party that supplies the whole job and manages subcontractors, and record in the quote who guarantees the watertightness of penetrations and fixings and for how long. For the relationship between client, main contractor and subcontractors, see also Comparing quotes.
Quality marks, guarantees and maintenance
You can recognise a good installer by their accreditations and memberships. InstallQ manages the accreditation schemes for installation companies, including the Zonnestroomsystemen (solar power systems) accreditation, with an annual inspection of completed work; Techniek Nederland is the trade association of installation companies, with general terms and conditions (AVIC) and a disputes procedure, and Holland Solar is the trade association of the solar energy sector. The older Zonnekeur quality mark built on the InstallQ accreditation; its website is currently unreachable, so only attach value to that quality mark if the company can demonstrate that it still holds it. Ask about the business liability insurance and about what happens if the company ceases to exist; guarantees are only worth something as long as someone is there to honour them, and in that case manufacturers' guarantees from the panel and inverter makers continue to run.
There are three kinds of guarantee, which you should not confuse. The product guarantee on the panels covers manufacturing defects and usually runs for ten to fifteen years, with premium brands up to twenty-five years or more. The performance guarantee promises that after a certain number of years a panel will still deliver a certain percentage of its original output, usually over twenty-five to thirty years. The installation guarantee from the installer covers the mounting work, the cabling and the watertightness and is usually much shorter, often two to ten years; this is the guarantee you fall back on in the event of a leak or loose cables, so look critically at the duration and the conditions. The inverter has its own product guarantee of five years as standard, which can be extended for a fee.
Maintenance is limited. In the Netherlands, rain largely washes the panels clean; cleaning is only needed for stubborn dirt, bird droppings or a very shallow pitch, and then with soft water without aggressive products or high pressure. More important is monitoring: the inverter's app shows whether the yield is in line with the forecast; a string that stops working or an inverter that frequently switches off because of grid voltage is quickly noticed that way. Visually check the cabling, the fixings and, on a flat roof, the ballast every year, and have the installation checked during a roof renovation or after a severe storm. When cleaning does make sense and how to do it safely is explained in having solar panels cleaned.
Checklist for the quote
- Number of panels, brand and type, and the total peak output in watt peak (Wp).
- A yield forecast in kilowatt hours per year, based on your roof, orientation, pitch and shade, with the assumptions included.
- Type, brand and capacity of the inverter, the choice of string, optimisers or micro-inverters and where the inverter will go.
- Mounting system and, on a flat roof, the wind calculation and the amount of ballast.
- Work on the consumer unit: dedicated circuit, protection, and whether the unit needs adapting or extending.
- Roofing work: penetrations, repair of tiles or bitumen, assessment of the condition of the roof, and who carries it out.
- Safety on the roof and the company's liability and CAR (contractor's all risks) insurance.
- Guarantees: product, performance, inverter and installation, with duration and conditions, and who the point of contact is.
- Who does the registration with the grid operator and whether you receive confirmation of it.
- The company's accreditation (InstallQ Zonnestroomsystemen or a Kiwa process certificate) and memberships (Techniek Nederland, Holland Solar).
- Handover with an inspection and measurement report, set-up of the monitoring and an explanation.
- Application of the zero VAT rate on the quote.
In summary: start with the roof, not with the panels. Have the roof covering assessed and, if necessary, renewed first, check the permit position and the VvE, choose an inverter that suits the shade and orientation, have the consumer unit put in order and register the installation with the grid operator. Design the system for self-consumption now that net metering is coming to an end, and record who guarantees the watertightness. On VerbouwPro you post your job free of charge and electricians, installers and roofers from your area respond.