This assignment is being carried out against the backdrop of a rooftop solar cadastre being drawn up in 2019 for the Greater Geneva area (around 2’000 km2), including the District of Nyon (located in the canton of Vaud), as part of the G2Solaire France-Switzerland INTERREG project (completed in May 2022), in which the Vaud Department of Energy (DIREN) is an institutional and financial partner.
The technical and methodological approach is based on that used for the Greater Geneva solar cadastre. Using the DSM (digital surface model based on LIDAR data from 2019), it is possible to calculate the slope, orientation, near and far shading (relief) and incident solar irradiation for any point on the territory (cell or pixel of 0.5m resolution) on an hourly basis, then aggregated by month and over the year. From this raw data, production potential indicators are calculated for each roof and building. Given the Canton's large surface area (3’000 km2), it is divided into several 3x3 km2 tiles (372 tiles in total). Each tile is calculated separately, and the results (raster) are then assembled for the whole canton. As sunshine conditions are highly variable, alternating between lowland and mountain areas, a specific meteorological file is compiled for each tile using the Meteonorm® tool. The calculation time is accelerated thanks to high-performance algorithms and the use of a GPU machine.
The development of the Vaud solar cadastre has made it possible to meet the challenge of processing a very large area (around 3’000 km2), 225’000 buildings, and the shading associated with the significant relief in certain regions of the canton (Jura and Alps).
The solar cadastre produced for the whole of the canton of Vaud provides reliable information on the gross solar potential, the total solar potential per section of roof and per building, and the potential for self-consumption of the solar power generated, taking into account an economic optimum. The information provided is an aid to decision-making, whether to motivate individual owners to take the plunge and install their own roofs, or to help building owners prioritise their investments. The database provided enables statistical processing of a large number of buildings at a time.
The solar cadastre will shortly be available online on the canton of Vaud's geoportal (thematic layer dedicated to energy - internet link).
Project partner(s)
Project leader - team
Gilles Desthieux
(HEPIA)
