For a client, we analysed the performance of large-scale direct air capture (DAC) projects to eliminate CO2 emissions. These projects attract huge investments and are used in net-zero roadmaps by associations and companies. Some projects plan annual capture capacities of up to 500,000 t CO2 (0.5 Mta). However, due to the low concentration of CO2 in the ambient air, about 2 million m3 of air have to be processed to capture a single metric tonne of CO2. This requires massive energy for fans and a large installation, where the air is treated with liquid sorbents. In such closed systems, sorbents have to be regenerated, which also requires massive energy. Even if green energy can be used for free, none of the projects that we analysed, keeps its sustainability promises.