An innovative pilot project in Füllinsdorf is demonstrating a new, practical way of using solar energy in greenhouses. The photovoltaic systems from the Vaud-based start-up Voltiris make it possible to produce solar power without affecting plant growth.
The EBL (Genossenschaft Elektra Baselland) is testing innovative PV installations in one of the greenhouses owned by the Füllinsdorf-based company Eschbach Gemüsebau. The installations allow the sunlight required for photosynthesis to shine through and thus do not impair plant growth. The technology is primarily aimed at operators of larger greenhouses, which until now could not be operated with conventional PV systems installed on their roofs.
Voltiris – innovative solution for power generation in greenhouses
Voltiris, based in western Switzerland, is breaking new ground in the production of renewable solar energy. Founded in 2022, engineers at this company headquartered in Epalinges (Vaud) near Lausanne have spent more than two years developing innovative photovoltaic systems that have the potential to transform electricity production. Their aim is to use areas in large greenhouses that were previously only used for plant cultivation to produce electricity. Conventional photovoltaic systems are unsuitable for greenhouses due to their design and the shade they create, as plants are naturally dependent on light. Voltiris offers a solution to precisely this problem: with a sophisticated optical system based on a spectral filter method, daylight is concentrated and projected onto conventional photovoltaic panels. However, the technology does not use the entire light spectrum for electricity production, but only that which cannot be used by plants for. Plant growth is not compromised and the previously unused space under the roofs of greenhouses can be used for electricity production. This construction method does not alter the exterior shell of the building and only minimal structural changes are required inside.
Eschbach Gemüsebau – open to new technologies
Andreas Eschbach and his wife are the fifth generation to run Eschbach Gemüsebau vegetable farm and 2BFresh Eschbach AG in Füllinsdorf near Liestal. The business employs around 20 people. For the past seven years, the family business has specialised in the production of microleaves, which it grows in large greenhouses on a hilltop plateau above the municipality of Füllinsdorf. Consumers from the catering and retail sectors appreciate the quality of the products, the cultivation of which requires expertise and skilful handling. Microleaves require consistent climatic and light conditions to achieve optimum growth. Andreas Eschbach was positive about the photovoltaic solution from Voltiris right from the start and was willing to equip one of his greenhouses with Voltiris’ PV systems. Andreas Eschbach: ‘I’m fundamentally open to new technologies and am not afraid to try something that no one has ever done before. We’ve been preoccupied with the issue of electricity consumption and in-house electricity production for some time, but until now there has been no solution that we have been able to combine with our greenhouses in a useful way. When I saw Voltiris’ all-new PV system, it was the first time that I’d seen a product that I could imagine working for us as well. Of course, it remains to be seen to what extent and whether the system will have an impact on plant growth, but so far I haven’t seen any negative effects on the production of our microleaves.’
In one of Eschbach’s greenhouses, around a third of the area under the roof has been fitted with Voltiris PV systems so far, with the next two-thirds scheduled to be installed in spring 2025. The plant will produce more than 50,000 kWh, which will cover a substantial share of the vegetable specialist’s entire electricity requirements. Installing the system was straightforward. Andreas Eschbach: ‘Installation took about two and a half weeks. The implementation by Voltiris and EBL went smoothly and we only had to clear the areas used for growing our crops for a short time. And apart from the installation of some V-beams, no structural changes had to be made to the greenhouse. The whole process has been positive so far.’
Pilot phase on track, EBL assessing launch of sales
EBL operates the plant in Füllinsdorf under a contracting agreement. It is financing and monitoring the installation and maintenance of the PV system by Voltiris, while the greenhouse operator buys the electricity produced at a fixed price. This eliminates the need for major investment and maintenance costs.
Demand for renewable energy generation options is high, and the Voltiris plant can be used to appeal to customers in the vegetable and horticultural sector for whom no satisfactory solution for generating electricity from solar energy has been available before now. The positive initial results for EBL make the energy producer optimistic that, in future, it will be able to offer the product throughout Germanspeaking Switzerland in a contracting agreement with Voltiris. EBL is taking a further step towards local energy production using existing infrastructures.
Find out more about Voltiris
A unique agrivolatics solution : The co-founders of Voltiris got their heads together and came up with a bright idea: using spectral filtering technology to develop the very first solar modules compatible with market gardening under glass, enabling sunlight to do two things at the same time. Find out more about them in our latest publication, “An overview of Cleantech Start-ups”, on page 122.
