Growing Food in the Dark with Artificial Photosynthesis

Header image: Plants are growing in complete darkness in an acetate medium that replaces biological photosynthesis. Credit: Marcus Harland-Dunaway/UCR

Most plants use a process called photosynthesis to capture energy from sunlight and use it to turn carbon dioxide and water into food. This ability makes plants primary producers, supporting huge webs of other lifeforms. However, photosynthesis is wildly inefficient, converting only about 1% of sunlight into plant biomass.

But now scientists at UC Riverside and the University of Delaware have found a way to remove the need for sunlight and create food using an artificial photosynthesis process, and published their results in Nature Food.

Their two-step electrocatalytic process converts carbon dioxide, electricity, and water into acetate, the main component of vinegar. Food-producing organisms then consume acetate in the dark to grow.

Using solar panels to power the electrocatalysis, this hybrid organic-inorganic system could increase the conversion efficiency of sunlight into food. It could be up to 18 times more efficient for some foods.

“With our approach we sought to identify a new way of producing food that could break through the limits normally imposed by biological photosynthesis.”

Electrolysers use electricity to convert raw materials into useful molecules and products. In this case, the researchers optimised the electrolyser to support the growth of food-producing organisms. They increased the amount of acetate produced while decreasing the amount of salt used, resulting in the highest levels of acetate ever produced in an electrolyser to date.

“Using a state-of-the-art two-step tandem CO2 electrolysis setup developed in our laboratory, we were able to achieve a high