2% is, I believe, the maximum efficiency ever recorded for conversion of sunlight to food calories. The typical yield on a farm is much lower (granted, some of

2% is, I believe, the maximum efficiency ever recorded for conversion of sunlight to food calories. The typical yield on a farm is much lower (granted, some of that goes to non-food biomass). The yield for crops grown to produce meat, especially beef, is MUCH lower. Fun fact: on a perfectly still day, photosynthesis of a corn field will be curtailed because the plants strip all the CO2 out of the available air, and do so remarkably quickly (IIRC in about five minutes in full sun.)