Technology of growing plants in the dark

Solar power has the potential to solve many of the inefficiencies of traditional agriculture, such as the need for large amounts of water, fertilizer, and land to grow crops.

Bioengineers have proposed a bold new method of food production that could radically change agriculture, making it more efficient, sustainable, and adaptable to environments like space. Dubbed 'agroelectricity , ' the system would replace traditional photosynthesis (which converts only about 1% of absorbed light energy into chemical energy in plants) with a reaction that efficiently converts carbon dioxide (CO ₂ ) into organic molecules that plants can use as food , Interesting Engineering reported on October 23.

The research team's agro-electric prototype. (Photo: Feng Jiao).

"Because electro-farming is independent of climate conditions and provides greater efficiency than traditional farming, it could serve as a useful method for supplementary food production when needed ," said study author Feng Jiao. "As global climate change impacts agriculture, advanced food production technologies are becoming increasingly important to stabilize food markets and support a growing population."

Photosynthesis , the process that enables life on Earth by converting sunlight into chemical energy in plants, is extremely inefficient. According to researchers, only a small fraction of the sunlight absorbed by plants (about 1%) is converted into usable energy. With growing food demand, limited arable land, and a looming climate crisis, improving this efficiency is essential.

In agro-electricity, photovoltaic panels would be used to power a chemical reaction between CO2 _and water, creating acetate, a molecule related to acetic acid (the main ingredient in vinegar). Plants would be genetically engineered to use acetate as a primary energy source rather than relying on photosynthesis. If the system were deployed on a large scale, the team estimates, it could reduce the amount of land needed for agriculture by 94%.

Robert Jinkerson, a bioengineer at the University of California, Riverside, who co-authored the study, said the technology was a major step forward. 'If we don't need to grow plants with sunlight anymore, we can take the environment out of it and grow food in a controlled environment indoors ,' he said.

The technology could transform farming into multi-story indoor vertical farms, where solar energy is harnessed outside the building to fuel the plants growing inside. Current versions of the farm-to-table technology have an energy conversion efficiency of about 4 percent, four times higher than photosynthesis, Jiao said, and the CO2 emissions _associated with food production are much smaller.

The method has the potential to solve some of the problems of traditional agriculture, such as the need for large amounts of water, fertilizer, and land to grow crops. Electrofarming would produce food in a controlled environment, allowing for more precise resource management and reducing the environmental impact of farming. Additionally, the method could mitigate the effects of climate change by decoupling food production from weather patterns and seasonal changes.

To achieve their goal, the team is developing genetically modified plants that 'eat' acetate. Plants naturally have a metabolic process that helps them break down food stored in seeds during germination. This process is shut down as soon as the plant begins to use photosynthesis. The bioengineers aim to reactivate the process in adult plants so they can use acetate as an energy source. While the initial research focuses on tomatoes and lettuce, the team plans to expand to high-calorie crops such as cassava, sweet potatoes, and cereals. Although the research is still in its early stages, other organisms such as fungi, yeast, and algae already use acetate as an energy source in nature. This means the technology could be commercially available to these organisms much sooner.