Why a solar cadastre?

Today, communities need to offer their residents and professionals a simple and effective way to assess the solar potential of their rooftops and parking surfaces.

Solar Cadastre is a tool that fits perfectly into a renewable energy development action plan.

Advantages of Archelios MAP

Proven precision

Proven precision

The solar potential of rooftops is evaluated thanks to the algorithms of our software archelios PRO, recognized as one of the most precise in the world according to independent international studies.

Find out more about Archelios PRO

A tool mastered by the community

A tool mastered by the community

The community becomes the data’s owner upon its reception and fully controls their diffusion.

Over 20 years of solar energy experience

Over 20 years of solar energy experience

Cythelia Energy, a unique experience as Solar Experts and Software Developers (Archelios suite).

Find out more about Cythelia Energy

A dedicated internet application

A dedicated internet application

The solar cadastre is delivered with a complet Internet application allowing its consultation by the citizens and companies involved. The application has been designed to be user-friendly, intuitive and ergonomic. It is available on all screens (smartphones, tablets, computers) and is supported by all current browsers.

Stages of a solar cadastre’s setup

1Shading calculation

The 3D representation of the territory is the raw material for the production of a solar cadastre.

We base our shading calculations on the latest national geographic institutions data with an accuracy of 25 cm in planimetry. All elements specific to the roof (chimney, roof windows, etc.) and surroundings (trees, other buildings, terrain) are taken into account in the solar survey.

We can also base our calculations on the 3D model of the city buildings when available, which allows us to have a geometric distinction of each side of the roofs in the solar cadastre.

2Solar energy received by each roof

Archelios MAP computes the solar trajectory hour by hour for each month of the year, taking into account the shading calculated in step 1.

The algorithms come from Archelios PRO, considered as the most accurate production forecasting software in the world by 2 independent international studies.

3Integrative Results in Community GIS

The results of the irradiation calculations are provided to the community in the form of standard GIS files (SHAPE and ESRI grid formats). These become the full property of the community upon receipt and may be exploited without copyright or any other commercial limit.

GIS files allow the community to cross the data of the solar cadastre with all the geographical data at their disposal. They can easily identify the most interesting rooftop on their territory or their own buildings, so as to encourage or initiate the most promising photovoltaic projects.

4Online Publication

The solar cadastre is made available to the general public and professionals of the territory via our internet application.

This application has been designed to be easy-to-use, intuitive and ergonomic. It adapts to all screens (smartphone, tablets, computers) and it is compatible with all popular Internet browsers (Chrome, Internet Explorer 11, Firefox, Edge, Safari).

Who are we?

Cythelia Energy has been a reference for more than 20 years, helping their customers throughout the lifecycle of solar projects, from the feasibility studiy to the complete project management of execution and construction.

Cythelia Energy designed Archelios suite, which is dedicated to PV from Design to Operations. The forecast production calculations made with Archelios PRO are the most accurate in the world, according to 2 independent international studies. 

All our solar cadastres made by us today

Soleil avec fond clair Website available
Soleil avec fond sombre Website in construction

The solar cadastre of
Grand Annecy


205,000 inhabitants over 539 km²
Analysis and visual rendering by rooftop
Most important rooftops and car parks
A green cadastre (vegetation potential) realized by VIZEA Research Department
Online access to the solar cadastre via our internet application

The solar cadastre of
Bordeaux and its region


774,000 inhabitants over 580 km²
Analysis and visual rendering by roof side
Visual aspect of the solar cadastre in conformity with the corporate identity and style guide of Bordeaux City
Online access to the solar cadaster via our internet application

Community testimonials

The solar cadastre is a formidable tool that is fully into keeping on with the Climate Plan and the ambitious energy transition objectives of Positive Energy Transition. The solar cadaster really encourages citizens to install photovoltaic panels on their rooftops.

Thierry BilletThierry BilletDeputy Mayor, Environmental Delegate of the City of Annecy

The solar cadastre helped us sensitize the population of Bordeaux on the solar potential of their rooftops, thanks to a simple and precise visualization in a few clicks. It is an integral part of our action plan in the energy field.

Patrick FaucherPatrick FaucherDirector of Energy, Ecology and Sustainable Development at Bordeaux City Hall