The researchers used solar panels to run a machine that converts carbon dioxide, electricity, and water into acetate—a molecule that can be diluted in water and used to feed plants. They then fed this mixture to algae, yeast, mushrooms, and a selection of commonly grown plants, including cowpea, tomato, canola, and rice. The algae and yeast both grew pretty efficiently on the acetate mixture, which isn’t exactly surprising, as scientists already know that these species can eat acetate. What was more surprising was that the crop plants also consumed the acetate and grew, even though they were growing in complete darkness.

But even if we could bring more tomato plants indoors, that wouldn’t necessarily free up much land to return to nature. The majority of agricultural land is used for pasture to graze animals or to grow feed for animals. A lot of the remaining land is used to grow commodity crops, such as wheat, soy, or corn, with only a relatively small amount of land used to grow fruits and vegetables. These commodity crops are extremely cheap to grow outside, so investing lots of time and money to grow them indoors doesn’t make a whole lot of sense. Growing plants in the dark might be useful in places where energy and space are scarce—like on a spaceflight to Mars—but it’s not suitable for most crops on Earth.