Does a flat roof need a mounting frame?

Flat roof systems are usually tilted with a frame, either south facing or in an east west pair. The east west layout fits more modules on the same area.

How much does a north facing roof lose?

A lot, often a third or more of the optimum, and the loss grows with steeper tilt. The calculator shows the figure for your exact location.

Is the optimum always due south?

For maximum annual yield, yes in most of Europe. If self-consumption matters more than the annual total, a west or east west layout can be the better choice.

Roof orientation and tilt calculator

Enter your location, direction and tilt. We compare your setup against the optimal one for that exact location and express the result as a share of the optimum.

Data set

These are reference values for Europe. Our country sites carry verified local data: myosolar.de, myosolar.at, myosolar.ch, myosolar.it, myosolar.es, myosolar.fr

Your inputs

Postcode or city

Roof tilt30°

System size

kWp

Roof direction

PVGIS was not reachable, so this result uses the market average yield and is an estimate rather than a location specific calculation.

Result

Share of the optimum-

Your setup30°, South1,100 kWh/kWp

Your inputs are kept in the address of this page, so you can bookmark or share this result.

Assumptions and sources

The market data behind the calculation above, with source, date and quality, followed by the modelling assumptions the result depends on.

Change our assumptions

These are estimates for your market. Enter your real rates and every result recalculates immediately.

Household electricity price

Sourced default: 0.2896 EUR/kWh

Market data with sources

Specific yield1,100 kWh/kWp
reference valuemyosolar working assumption, not a quotation2026-08-01
Illustrative only. Never print in an article. Use the market specific constant instead.
Household electricity price0.2896 EUR/kWh
reference valueEurostat, EU average household electricity price2025-12-31
European reference value. Choose your country site for local figures.

Rules that apply in your market

These figures are European reference values, not the rules of a single country. Our country sites carry verified local data.

Frequently asked questions

Does a flat roof need a mounting frame?: Flat roof systems are usually tilted with a frame, either south facing or in an east west pair. The east west layout fits more modules on the same area.
How much does a north facing roof lose?: A lot, often a third or more of the optimum, and the loss grows with steeper tilt. The calculator shows the figure for your exact location.
Is the optimum always due south?: For maximum annual yield, yes in most of Europe. If self-consumption matters more than the annual total, a west or east west layout can be the better choice.

Matching guides

This is a transparent model for orientation, not an offer, not a yield guarantee and not financial advice. Binding figures need a site survey.