Method transparency
How we calculate your estimate
The instant estimate on "My roof" and the proposal that follows rely on a model published here without filter: the same data, the same assumptions, the same caution — so you can verify every figure instead of having to take our word for it.
1. Solar production
Public data, not an in-house figure
The yield (how many kWh each installed kWc produces per year) comes from PVGIS (European Commission, Joint Research Centre) — the most-cited public reference for solar irradiation in North Africa. We don't estimate it ourselves: the full table, city by city and tilt by tilt, is published as-is on our Solar yield in Morocco page. Without a GPS pin dropped on the map, the instant estimate starts from a default latitude (Casablanca, the most central point in our service area) and a due-south orientation — the theoretical optimum — then refines once a real pin is placed.
Source
System losses
Default orientation
2. A range, not a single number
Why a low bound and a high bound
The production PVGIS reports is already net of generic system losses (14%). We apply an ADDITIONAL climate confidence band on top: the high bound is the raw PVGIS figure; the low bound reduces it by a factor combining the thermal derate of a hot coastal summer (panels lose efficiency as they heat up), soiling and haze — real, documented losses, never a pessimistic figure invented just to hedge. This range (never a single confident number) is the same logic as the confidence band shown live on the estimator.
3. Savings: self-consumption first
We only value what YOU consume yourself
Law 82-21 organizes low-voltage self-production in Morocco: your system produces electricity, part of it is consumed directly at home (self-consumption), the rest flows onto the grid. Our estimate only values the self-consumed share — at the utility rate for your bill bracket, the same grid you already pay.
We add NO surplus resale line to the grid. This isn't an oversight: ANRE has published a resale tariff decision for medium/high-voltage installations (MT/HT), but no equivalent tariff for low-voltage residential (BT) has been published to date. As long as this BT tariff doesn't exist in writing, pricing in a resale income would mean inventing a number — exactly what we refuse to do.
4. Preliminary, refined after a visit
A starting point, never a final quote
The instant estimate is calculated in seconds from your bill (and, if you drop one, a GPS pin on your roof). It sees neither your neighbourhood's real shading, nor your roof's condition, nor the equipment ultimately available. That's why every estimate carries the "preliminary, refined after a visit" note: the final figure — the one on your signed proposal — always comes after a free, no-obligation technical site visit.
To go further
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