I was speaking figuratively. Eew.
The point was that growing edible foodstuff at the point of use obviates transportation of materials, produce, and
shipping-friendly packaged product. You could power the violet LEDs with road-taxed high-test gasoline and come out ahead.
Plus which:
science.howstuffworks.com: Researchers Create Protein Powder With Just Microbes, Electricity, CO2 and Water
Once again, 'fossil' fuels are expedient but not fundamental.