Every year, the Swiss start-up Climeworks wants to suck up to 4,000 tonnes of CO2 directly from the air and deposit it underground. Orca, as the plant is called, went into operation on Iceland at the beginning of September. Orca consists of eight large containers that suck in CO2 with the help of fans and filter it out. Climeworks’ plants are powered by renewable energy. Icelandic carbon storage company Carbfix mixes the captured CO2 with water and pumps it underground. There, the mixture reacts with basalt rock and mineralises into solid carbonate in a few years. The quantities of CO2 that Orca captures are still relatively small. The company’s goal is to increase them significantly. A major problem with the method is its high cost. They are said to be in the range of several hundred dollars per tonne of CO2. In the long run, however, the price is supposed to drop to under 100 dollars.