Buying solar panels: what to look for

Panels differ in power per unit, looks and price per watt-peak. On a small roof you often pick high power per panel so you need fewer modules for enough kilowatt-peak. On a large roof, price per watt-peak matters more. We explain the difference between cell types on the monocrystalline versus polycrystalline comparison page.

Every panel sold in the Netherlands must meet European quality standards. The real difference is in mounting, layout and matching the inverter. A good choice always starts with a roof survey.

At SolarFast we look at tiled roof, bitumen or a flat roof with ballast. Shade from a chimney or dormer decides whether string or micro-inverters fit. In apartment blocks we also check whether the owners' association agrees and where the cable runs to the fuse box.

Solar panels produce direct current. An inverter converts that to alternating current for your home and the grid. Inverter quality and power partly determine your yield. Prefer panels and inverter as one matched system, not loose parts from different suppliers.

Inverters in the Netherlands must meet the European grid connection requirements (the RfG network code). On the Netbeheer Nederland list you can check which types have been assessed against them; the list is a verification aid, not exhaustive. Ask explicitly for brand, model and power in your quote.

Look at MPPT trackers: they keep production per string as high as possible. If shade on your roof is unavoidable, micro-inverters are often smarter. We compare string and micro side by side on string inverter versus micro-inverters. More on what an inverter does is on what is an inverter?.

To feed power back to the grid you need a meter that registers consumption and feed-in separately. An old Ferraris meter without feed-in registration cannot do that and must be replaced. If your current meter cannot measure feed-in, your grid operator usually installs a smart meter at no charge, Milieu Centraal explains. If you voluntarily switch from a suitable analogue meter to a smart meter, charges may apply.

The inverter always connects on a separate circuit in the fuse box. Sometimes wiring, residual-current devices or the main fuse need updating. If you are unsure about your fuse box, raise it in the advisory meeting.

For new connections 3x25 amps is the standard; many existing homes still have a single-phase connection. If you plan solar alongside a heat pump, charger or large system, a heavier connection may be needed. Upgrading costs a one-off fee; moving to a connection above 3x25 amps also raises your fixed grid charges. The ACM explains what to watch before enlarging your connection.

Choose a skilled installer with its own fitters, clear warranty terms and a fixed contact if something goes wrong. Ask for references, certification and how mounting and finish are done. Those shape your result as much as the panel itself.

SolarFast works with its own fitters from Amstelveen. We are InstallQ certified and work to fixed safety and quality standards. Your quote explains why certain panels and a certain inverter fit, and what happens if something ever fails. No subcontractors you only meet on installation day.

There are several warranty layers. Product warranty covers manufacturing defects on the panel or inverter. Performance warranty states how much the panel still delivers after 10 or 25 years. Installation warranty covers the fitter's work. Sometimes a system or yield warranty is added.

Check that warranty runs from the manufacturer, not only from the installer. If your supplier goes bankrupt, you still want to reach the manufacturer. Also ask whether warranties transfer when you sell the home.

Our quotes list factory warranties on panel and inverter separately, plus our installation warranty. That way you know upfront what to expect if something goes wrong.

Request at least three no-obligation solar panel quotes, as Milieu Centraal advises. We prefer to plan a survey at your home for that: you see more on the roof than over the phone. Line the quotes up on the same points: total watt-peak, brand and model of panels and inverter, mounting materials, all work from start to clean-up, warranties and what is included. The quote checklist helps you miss nothing.

A good quote is an all-in price. That should cover scaffolding, connection to the fuse box, monitoring, waste disposal and sometimes a small recycling fee per panel. You also want a layout sketch on the roof and the inverter location indoors.

The cheapest line is rarely the full bill. Unsure about another supplier's quote? Send it to us and we will review the panels, inverter and terms with you.

After signing the quote, a few practical steps come before panels go on the roof. Your grid operator must know you will feed in, and your energy supplier must be able to settle the installation. Often your installer registers with the grid operator; check in your contract who does which step. Milieu Centraal describes the steps before and after installation.

After installation you register the system on Energieleveren.nl. You also enter inverter brand and model; the system checks it against the approved list. Register the panels with your energy supplier too so feed-in can be settled. How that works is in our article on net metering.

Check your buildings insurance as well. Solar panels are not automatically covered. Nail-fixed systems usually are; click systems sometimes are not. Tell your insurer about the installation and read the policy terms.

You request a no-obligation quote via our form or by phone. At SolarFast you get a response within 24 hours with a proposal based on your use and roof. After you agree, we schedule installation, usually within three weeks, with no deposit required.

The quote states total power in kWp, the inverter type, the mounting system, all warranties and who handles registrations. No extra lines that only appear on installation day. Want to know how much power you can generate? Read our piece on yield and return.