Innovatie en Demonstratie Centrum CO2 uit Buitenlucht: Resultaten Skytree Cumulus (Bèta)

The greenhouse horticulture sector faces the significant challenge of completely eliminating fossil CO₂ emissions in the long term. At the same time, CO₂ remains essential for maximizing the photosynthetic capacity of plants. Direct Air Capture (DAC) could serve as a new CO₂ source, but its functioning, integration into greenhouse operations, CO₂ quality, and required inputs for such systems are still largely unknown. The IDC CO₂ project provides a platform for the independent evaluation of DAC technologies, providing insight into the potential contribution of these systems to the sustainability of greenhouse horticulture. As part of the project, several DAC companies will deploy their systems in the greenhouse facilities of Wageningen University & Research in Bleiswijk. The research aims to collect data in a semi-practical setting to: 1) assess CO₂ quality and identify potential phytotoxicity risks, 2) evaluate performance in terms of production capacity, concentration, and energy efficiency 3) quantify necessary inputs such as sorbents, and analyse outputs, such as condensate water, in terms of volume and quality and 4) explore practical implementation challenges. This report presents the key findings from the first tested DAC machine: a beta version of the Skytree Cumulus. In 2025, the Skytree Stratus is expected—a higher-capacity machine specifically developed for greenhouse horticulture. Since the Skytree Cumulus and Stratus are designed for different applications, the research results from the Cumulus trial are not fully representative of the performance of an optimized DAC system for greenhouse horticulture. Nevertheless, the Cumulus could still be evaluated on points 1, 3, and 4, as both systems use a similar sorbent and share core processes. The production capacity, concentration, and achieved energy efficiency were also tested, identifying potential areas for improvement.