« Devis clair, sans surprise, primes comprises. Un seul interlocuteur du début à la fin. Je recommande sans hésiter pour le photovoltaïque. »
Pierre M.Tournai
Solar panels · Understanding the types
Which type of solar panel? the guide to choosing the right efficiency
Monocrystalline, polycrystalline, N-type, bifacial: they all produce electricity from sunlight, but their efficiency, lifespan and cost differ. In Belgium, monocrystalline dominates residential. This guide compares the technologies to point you the right way.
- 20–22%
- mono N-type efficiency
- 25–30 years
- linear warranty
- ~950 kWh
- per kWp/year in Belgium
20–22%monocrystalline efficiency
N-typelatest generation
The technologies
Understanding each type of panel
They all capture light, but the cell makes the difference. Here’s what each technology brings in practice.
- Monocrystalline P-type 19–21%
The most widespread technology. Pure silicon cells, black, good efficiency. Reliable and proven, it’s the standard choice for Belgian residential.
- Monocrystalline N-type 21–22%
The latest generation: better efficiency, slower degradation (near-zero LID) and better behaviour in low light. The rising standard in 2026.
- Bifacial +5–15%
The panel captures light on both faces. The gain depends on the albedo (reflective surface under the panel). Attractive on flat roofs or on raised structures.
- Polycrystalline 17–19%
Blue cells, cheaper but lower efficiency. Almost gone from the Belgian residential market in favour of monocrystalline, whose prices have caught up.
- Efficiency per m² 200–220 W/m²
A 400 Wp mono N-type panel takes up about 1.8 m². The higher the efficiency, the less roof surface you need for the same production.
- Warranty 25–30 years
Linear production warranty (85–92% after 25 years depending on the technology). N-types offer the slowest degradation and the best long-term warranty.
* Indicative values for mainstream panels in 2026. Real-world performance depends on the model and the installation — confirmed during the survey.
Help choosing
Which type for which situation?
The right type depends on your roof, your budget and your goals. Here’s how to find your way.
Lean towards monocrystalline N-type
- Better efficiency per m²Ideal when roof space is limited — more watts per panel.
- Slower degradationN-type technology holds its production better over the years.
- Better in low lightProduces more in overcast weather — a real advantage under Belgian skies.
- Rising standardInstallers are switching to N-type in 2026; prices are catching up with P-type.
Lean towards P-type or bifacial
- Spacious roof, tight budget→ P-type stays competitive when space isn’t an issue.
- Flat roof or reflective surface→ Bifacial captures light from below and gains 5 to 15%.
- Large installation (> 10 kWp)→ Bifacial on a raised structure maximises production per panel.
- Roof with multiple orientations→ The type matters less than the inverter and the optimisers.
For which roof
Which type for your roof?
The roof guides the choice as much as the budget. Three common situations:
-
Pitched roof, limited space
Monocrystalline N-type maximises production per m². Each panel produces more, so you need fewer of them to reach the target output.
-
Flat roof
Bifacial on a tilted structure captures the light reflected by the membrane. An extra gain that strengthens the payback.
-
Large roof (> 10 kWp)
On a large installation, bifacial N-type combines high efficiency and a bilateral gain. The extra investment pays off through the increased production.
The panel type isn’t everything
The inverter and the optimisers weigh as much as the panel on real production. And the roof (orientation, pitch, shading) remains the first factor.
Glissez la poignée pour comparer
Real case · family home, Namur
From P-type to N-type: more production on the same surface
A 30 m² south-facing roof where the customer was torn between P-type and N-type. We installed 14 monocrystalline N-type panels of 420 Wp: 5.9 kWp on the same surface that would have held only 5.3 kWp in P-type. An 11% gain in annual production.
- 5.9 kWpon 30 m²
- +11%vs P-type same surface
- ~5,600 kWhof annual production
Customer reviews
They chose wendows
5.0/5 · 1verified reviews
Compare the technologies
Mono P-type, N-type or bifacial?
The table to see the differences at a glance. Polycrystalline is no longer relevant in residential in 2026.
| Critère | Mono N-typeVous êtes ici | Mono P-typeVoir la gamme → | BifacialVoir la gamme → |
|---|---|---|---|
| Efficiency | 21–22% | 19–21% | 21–22% + rear gain |
| Annual degradation | ~0.3%/yr | ~0.5%/yr | ~0.3%/yr |
| Low light | Very good | Good | Very good |
| Price | 2026 standard | Slightly less | Slightly more |
| Bilateral gain | No | No | +5–15% |
| Production warranty | 25–30 years | 25 years | 25–30 years |
| Ideal for | Standard residential | Tight budget, large surface | Flat roof, raised structure |
Indicative benchmarks for mainstream panels in 2026. The optimal choice depends on your roof — we fine-tune it at the survey.
- the full package
Solar kit
Panels + inverter + installation: the turnkey kit sized for your consumption.
See the kits → - the brain
Inverter
The type of inverter (string, micro, hybrid) weighs as much as the panel on production.
See the inverters → - to pair with
Optimisers
Maximise each panel independently in case of shading or mixed orientations.
See the optimisers → - the basics
Solar roof
Orientation, pitch, roof covering: the roof remains the first factor in production.
Check my roof → - to pair with
Battery
Store the surplus for the evening. The battery multiplies your panels’ self-consumption.
See the batteries → - ↑ category
All things photovoltaic
An overview of our solar panels in Belgium: production, inverters, batteries and incentives.
Back to the solar guide →
Indicative price 2026
How much does a solar panel cost by type?
The price per Wp varies little between P-type and N-type in 2026. Bifacial is slightly more expensive. Here are some benchmarks for installed hardware.
See full solar kit prices →* Indicative ranges for installed hardware (panel only). The price of a complete kit depends on the total output and the inverter.
- Mono P-type panel 400 Wp ~€120–160per panel, excluding installation
- Mono N-type panel 420 Wp ~€140–180per panel, excluding installation
- Complete 6 kWp kit installed €6,000–9,000panels + inverter + installation
- Reduced VAT 6%for renovation (home > 10 years old)
Panel types FAQ
Your questions about panel types
Is polycrystalline still worth it in 2026? +
No, for residential. Monocrystalline has caught up with polycrystalline on price while offering better efficiency. Poly is still used in some large industrial installations, but it has all but disappeared from the Belgian consumer market.
What’s the difference between P-type and N-type? +
N-type uses phosphorus doping (instead of boron for P-type). The result: better efficiency, slower degradation and better behaviour in low light. In 2026, the N-type premium is minimal and most installers offer it as standard.
Is bifacial worthwhile on my roof? +
The bilateral gain depends on the reflectivity beneath the panel. On a flat roof with a light membrane or a raised structure, the gain reaches 10–15%. On a classic pitched roof, the gain is marginal and the premium isn’t always justified.
How many panels do I need for my home? +
It depends on your annual consumption and the available surface. For an average Belgian household (~4,000 kWh/year), 10 to 14 panels of 400 Wp are enough (4–6 kWp). We size it precisely at the survey.
Do panels produce in Belgium, even in overcast weather? +
Yes. Panels produce as soon as there is light, even diffuse. In Belgium, annual production is around 900 to 1,000 kWh per kWp installed. N-types produce a little more than P-types in overcast weather.
What warranty applies to solar panels? +
Two warranties: the product warranty (manufacturing defects, 15–25 years) and the linear production warranty (85–92% of output after 25–30 years). N-types offer the best linear warranties on the market.
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