David Jossen
Managing director of Energie Electrique du Simplon EES
06/19/2023, 10:00
| Blog
Alpiq launched the Gondosolar project in 2021 through its subsidiary Energie Electrique du Simplon SA. Gondosolar has since pioneered various other project ideas. As the most advanced project in Alpiq’s alpine photovoltaics (PV) programme, it has already reached significant milestones: the environmental assessment was carried out last summer, and the planning application can be submitted in July 2023. In addition, the project relies on a new, innovative system design with PV panels in a tree structure on account of its environmental compatibility. David Jossen, managing director of Energie Electrique du Simplon EES, explains more in an interview.
David, in the Gondosolar project, new ‘solar trees’ will be used with the photovoltaic panels. How did this change come about?
During the intensive project development work, it became apparent that the previous system design with inclined, south-facing PV panels on steel tables were not the best option for the Gondosolar project. On the one hand, integrating the system into the alpine landscape and the soil protection are major challenges. The uneven ground and the requirement for as little earthwork as possible meant that the ‘table’ construction could hardly have been pre-fabricated in series. This would entail considerable additional costs for the project – particularly regarding installation in the difficult-to-access area of the Alpjerung. The benefit of the tree structure is that the system can be pre-constructed in the production facility. On the other hand, the area is exposed to fierce winds in winter, which can lead to large snow drifts with the risk of snow accumulating in open spaces. This has caused us to re-evaluate all available options in terms of system design.
What are the advantages in system design of using a tree structure rather than the previous ‘table’ design?
The tree structure of the PV panels draws on the experience of avalanche barriers. They are specifically based on experience with snow drift control measures to contain snow avalanches. The shape mimics the so-called baffle, which is known and proven to create wind turbulence that blows snow out of the structure’s base and lower ‘arms.’ The Gondosolar project team has worked with a natural hazards consultant and a PV technology consultant for the new system design. These consultants have already gained initial experience with the tree structure. For this purpose, 16 bifacial PV panels are mounted crosswise on a vertical mast, creating a tree-like structure. It will now be further investigated with a test facility comprising several ‘solar trees.’
With Ovronnaz Solar, the Grands Plans solar park in Grimentz and Prafleuri, Alpiq as a partner has other alpine PV systems in the pipeline in addition to the Gondosolar project. Is the tree structure system design also planned for these?
Gondosolar is essentially the pioneer project for other alpine PV systems, as it was one of the first alpine PV projects to be launched as early as 2021 and the environmental assessment was carried out last summer. This means that it is more advanced in terms of planning than most other projects, which can now benefit from the experience of project development. However, which system design makes the most sense for which project primarily depends on the respective geographical and environmental conditions. With Gondosolar, firstly the wind-exposed location, the uneven ground and the hard-to-reach geographical location have been decisive for us in terms of changing the design. That being said, we are also very much focussed on the environmental impact: we want to achieve optimal integration into the sensitive alpine landscape, preserve the soil protection as much as possible and keep earthwork to a minimum. From today’s perspective, the ‘solar trees’ seem to be the best solution for the Gondosolar project.