What's the areal efficiency of this process? The primary input to the growth reactor is hydrogen gas. The primary input to producing renewable hydrogen is elec

What's the areal efficiency of this process? The primary input to the growth reactor is hydrogen gas. The primary input to producing renewable hydrogen is electricity. A solar farm in a good location, like Desert Sunlight, achieves an annualized power density of about 10 megawatts per km^2 (0.1 megawatts (100 kW) per hectare). It takes about 50 kWh of electricity to produce a kilogram of hydrogen via electrolysis: https://www.energy.gov/eere/fuelcells/doe-technical-targets-hydrogen-production-electrolysis https://www.energy.gov/eere/fuelcells/doe-technical-targets-... According to this paper by some of the people behind Solar Foods, "Carbon emission avoidance and capture by producing in-reactor microbial biomass based food, feed and slow release fertilizer: Potentials and limitations" ( https://www.researchgate.net/publication/326571432_Carbon_emission_avoidance_and_capture_by_producing_in-reactor_microbial_biomass_based_food_feed_and_slow_release_fertilizer_Potentials_and_limitations https://www.researchgate.net/publication/326571432_Carbon_em... ), it takes about 560 kg of hydrogen to produce 1000 kg of dry microbial based biomass with a protein content of 70% [1]. At 100 kW/ha, a solar farm in a good location can produce (100 / 50) * 24 * 365 = 17,520 kg of H2 per hectare, per year. That in turn can produce 17520 / 0.56 = 31,286 kg of dry microbial biomass per year, containing 31286 * 0.7 = 21,900 kg of protein per hectare per year. According to some (admittedly quite dated, circa-1972) data collected on this page, the crop with the best areal productivity of edible protein is soybeans at 400 kg/hectare/year. https://en.wikipedia.org/wiki/Edible_protein_per_unit_area_of_land https://en.wikipedia.org/wiki/Edible_protein_per_unit_area_o... According to table 2 in the article, the essential amino acid profile of this bacterial protein is equal or superior to soy in all respects. The areal protein productivity of a solar farm coupled to microbial reactors may be more than 50 times that of growing conventional crops. If the bacterial protein is used as animal feed for animals with a good feed conversion ratio (e.g. farmed salmon), it even looks like you could get more animal protein per hectare this way than a vegetarian diet can achieve with conventional farming. And the water requirements are reduced even more drastically than the area requirements. And the electricity production can take place on non-arable land. I would be interested to see more modern areal productivity figures for soy; presumably there has been some additional intensification since the early 1970s, though not 50x improvement. [1] Hydrogen consumption is not stated directly, but they say that hydrogen at $3/kg makes up 60% of the $2800 cost to produce a dry tonne of bacterial biomass. (0.6 * 2800) / 3 = 560 kg of hydrogen.