I'd imagine it's sunlight / artificial light + growth to harvest time. It takes energy input to make food calories, there's really no getting around it with tec

I'd imagine it's sunlight / artificial light + growth to harvest time. It takes energy input to make food calories, there's really no getting around it with technology. The only way to increase the calories in the harvested food is intense direct light in a short time, or less intense (shaded) light over a longer time. In vertical farms, that's a higher cost of production.