In the dark. How well does the solar cell work in the dark? The only thing truly in the dark are the researchers.
I see reading comprehension skills are not your forte.
They are using solar power to run a electrochemical reaction cell that takes water , CO2 and the electricity from the solar cell and turns that into a chemical called acetate. When mixed with water acetate is acetic acid commonly known as vinegar.
I’m ready for the part you missed here it is pay attention. They then take that liquid acetate and put it in tanks in THE DARK with what they want to grow. Since plants can directly uptake acetate and use it for their cellular respiration those plants can now grow in that tank wait for it..wait for it IN THE DARK without any sunlight. That is a massive breakthrough it decouples the growing of plants from needing sunlight on them.
The electrochemical cell can use electricity from any source they could have used wind turbines or gas turbines or nuclear power. The electrochemical cell doesn’t care where the DC voltage comes from.
The reason they used a solar cell is to compare the efficiency per square meter of surface area in sunlight to that of a square meter of plants doing conventional photosynthesis that is why they uses solar cells. Their process is 18 times more output per square meter of sunlight and that is a big deal try to keep up and welcome to the 21st century.