« 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 · Optimisers
Power optimisers: every panel performs at its peak
A shaded panel holds back the whole string on a string inverter. An optimiser, placed under each panel, isolates it electrically: it produces at its own maximum without affecting its neighbours. The sweet spot between string and micro-inverter, ideal for complex roofs.
- +5–25%
- on a shaded roof
- Per panel
- individual monitoring
- Safety
- panel-by-panel shutdown
Per panelindividual optimisation
+5–25%gain with shade
Technical specifications
What optimisers are really worth
The figures that matter to know whether optimisers are worth the premium on your installation.
- Function DC-DC per panel
The optimiser adjusts the voltage and current of each panel independently. The result: a shaded or dirty panel no longer drags down the others.
- Gain with shade +5–25%
The gain depends on how significant the shading is. On a shade-free roof, the gain is near zero — optimisers aren’t justified.
- Monitoring Per panel
Each panel is tracked individually in the app. A faulty or dirty panel is detected immediately.
- Safety SafeDC
During an outage or intervention, each optimiser brings its panel down to 1 V. No more high voltage on the roof: safety for firefighters and technicians.
- Compatibility With string inverter
Optimisers combine with a compatible string inverter. No need for micro-inverters: a single central inverter is enough.
- Lifespan 25 years
25-year warranty, aligned with the panels’ lifespan. No mid-life replacement, unlike a string inverter.
* Indicative values. The real gain depends on the shading and the configuration — assessed at the survey.
In full transparency
Optimisers: benefits & limits
Optimisers aren’t always necessary. Here’s when they’re worth the premium and when you’re better off without.
Where they shine
- Each panel independentOne panel’s shading or dirt no longer affects the others.
- Per-panel monitoringImmediate detection of a faulty or underperforming panel.
- SafeDC safetyPanel-by-panel voltage shutdown during an intervention.
- Cheaper than micro-invertersThe cost/performance compromise between pure string and micro-inverter.
What you should know
- Useless without shadingOn a homogeneous roof with no shade, the gain is near zero — a needless cost.
- Premium per panelAround €40–70 per optimiser, multiplied by the number of panels.
- Extra component on the roofOne more element per panel, exposed to the weather (but warranted 25 years).
- Inverter compatibilityRequire a compatible string inverter (usually the same brand).
For which roof
Are optimisers right for you?
It all depends on your roof. Three situations where they’re justified:
-
Partial shading (chimney, tree, dormer)
Does a chimney’s shadow touch 2–3 panels? Optimisers free the other panels from that constraint.
-
Multiple orientations
Panels on two different pitches (east + west, for example). Optimisers let each orientation produce at its maximum.
-
Enhanced safety
The SafeDC function shuts down the voltage panel by panel. Required in certain contexts (public buildings) and reassuring for everyone.
Optimisers or micro-inverters?
Micro-inverters go further (AC conversion per panel, 25-year lifespan). But they cost more. Compare with the solar inverter to choose the right architecture.
Glissez la poignée pour comparer
Real case · shaded roof, Namur
A chimney that was dragging down production — solved by optimisers
A 5 kWp installation where the chimney shaded 3 of the 12 panels at the end of the day. The entire string was losing 20% of production. After adding optimisers, each panel produces independently: annual production has recovered 15%.
- +15%of production recovered
- 12 optimisersinstalled in 2h
- Monitoringper panel now
Customer reviews
They chose wendows
5.0/5 · 1verified reviews
Compare the architectures
String alone, optimisers or micro-inverters?
Three possible architectures for your installation. The choice depends on shading and budget.
| Critère | Optimisers + stringVous êtes ici | String aloneVoir la gamme → | Micro-invertersVoir la gamme → |
|---|---|---|---|
| Shading management | Per panel | String affected | Per panel |
| Price | In between | The gentlest | The highest |
| Monitoring | Per panel | Overall | Per panel |
| SafeDC safety | Yes | No | Yes |
| Lifespan | 25 years (optim) + 10–15 (inv.) | 10–15 years | 20–25 years |
| Battery possible | With hybrid | With hybrid | Separate AC battery |
| Ideal for | Partial shading, safety | Simple roof, budget | Very complex roof |
Indicative benchmarks. The choice depends on your roof — we assess the shading at the survey.
- the brain
Inverter
The string inverter is still needed with optimisers. We choose a compatible one.
See the inverters → - all-inclusive
Solar kit
Optimisers fit into the kit if your roof justifies them.
See the kits → - the panels
Panel types
N-type, P-type, bifacial: optimisers work with all types.
See the types → - to pair with
Battery
Combine optimisers and a hybrid inverter for storage and backup.
See the batteries → - the basics
Solar roof
Assess your roof’s shading and orientation before choosing the architecture.
Check my roof → - ↑ category
All things photovoltaic
An overview of our solar panels in Belgium.
Back to the solar guide →
Indicative price 2026
How much do optimisers cost?
The premium is €40 to €70 per panel. It’s only justified if shading or mixed orientations call for it.
See full solar kit prices →* Indicative ranges per installed optimiser. The production gain must offset the premium over time.
- Optimiser (unit) €40–70per panel, installed
- Set of 12 panels €500–850total premium installed
- Compatible inverter €800–1,500compatible string required
- Reduced VAT 6%for renovation (home > 10 years old)
Optimisers FAQ
Your questions about optimisers
Are optimisers always necessary? +
No. On a simple roof, with no shade and a single orientation, a string inverter alone is enough. Optimisers are only justified if shading or mixed orientations reduce the production of some panels.
How much production do you gain? +
The gain depends on how significant the shading is. On a lightly shaded roof, the gain is 5 to 15%. On a heavily shaded roof, it can reach 25%. On a shade-free roof, the gain is near zero.
Can optimisers be added to an existing installation? +
Yes, provided the inverter is compatible. If it isn’t, we replace the inverter at the same time. We check compatibility before proposing.
What’s the difference with micro-inverters? +
The optimiser is a DC-DC converter: it adjusts the voltage but doesn’t convert to AC. It stays cheaper than a micro-inverter and requires a central string inverter. The micro-inverter converts directly to AC under each panel.
Are optimisers reliable? +
Warranted 25 years, they’re designed to last as long as the panels. No moving parts, sealed electronics. Reliability feedback is excellent on the major brands.
Which brands do you recommend? +
SolarEdge is the leader in optimisers (a closed system with a SolarEdge inverter). Tigo offers optimisers compatible with other inverter brands. We choose based on your configuration.
Get your free optimisers quote within 48h
Free shading assessment, precise sizing, incentives calculated. Describe your project in under a minute.
- Free and no obligation
- On-site shading assessment
- Installed by our certified fitters