Maybe a little different compared to the Bay area, but I live outside Jackson, Wyoming. It's currently about 16F outside and there is 12" of snow on the ground. We have access to fresh locally grown tomatoes, lettuce, and other things like that year round.
https://verticalharvestfarms.com/
Just as you mention, it is high quality and tastes great!
Also, it isn't trucked in from Salinas Valley CA which is 1,000 miles away.
Of course, grow-lights in Wyoming will be mostly coal powered, whereas a field in Salinas is renewable energy.
Assuming I am doing the math right, shipping 1 ton of food 1000 miles (refrigerated) is roughly ~30-40kg of CO2, or about 7g-CO2 per tomato (6oz tomato).
A tomato plant is roughly ~40lbs/sqft/year (hydroponic, 40W/sqft), so about 20Wh/g, or about 1.4kg-CO2 per tomato for coal. Maybe more like 1kg-CO2 for the mix in Wyoming.
... depends on what you are trying to optimize, I guess, and how much natural light you can harvest in the vertical greenhouse.
That's not factoring in that the field in Salinas has to use much more water, use pesticides and fertilizer, and tilling and harvesting, which all require more energy than the local hydroponic garden.
Of course the environmental cost should be factored in. I'm still curious if hydroponics (or geoponics, in this article's case) actually winds up having a better carbon footprint than traditional agriculture.
Couldn't some of the gains of indoor vertical farming be gotten with greenhouses? Namely protection against pesticides and minimal water loss from evaporation.
The whole premise of a 'vertical farm' seems bunk to me for this reason. If you want ultrafresh local food in a climate which doesn't support it, with precise control over the growing conditions.. well that's precisely what greenhouses provide. A 'vertical farm' is what you get when you make a greenhouse worse by removing the windows for no real reason, then try to compensate for that with futuristic vibes. Put a greenhouse 15 minutes outside the city and you'll save money with cheaper land and free solar power (greenhouses may also have supplemental lighting or heating if needed.) You get all the freshness advantages of local production, but cheaper. The only 'downside' of greenhouses relative to vertical farms that I can think of: greenhouses are old technology that won't make yuppies feel like they're living in a sci-fi movie.
IIRC in a documentary about spanish produce vs german greenhouse produce they calculated that german produce is much higher in co2 output than spanish, even when the spanish produce is delivered by a semi all the way from Spain! Simply because in spanish climate there is no need for a greenhouse to grow e.g. bell peppers or tomatoes.
I only found a german source: https://www.umweltdialog.de/de/verbraucher/lebensmittel/2015...
it says:
German, heated greenhouse outside of season: 9.3 KG of CO2 per KG tomatoes (well, that is unexpectedly high)
Non heated greenhouse: 2.3KG of CO2 per KG tomatoes
open land in spain: 0.6KG of CO2 per KG
open land in Germany in season, conventional: 0.085KG of CO2 per KG
open land in Germany, organic: 0.035KG of CO2 per KG
although it's from 2015, I don't think that much has changed in 5-6 years to make up such a big difference between heated, nonheated, open land and regional. It also factors in transport from Spain to Germany which is why open land in spain has a higher co2/kg than german open land.
edit: of course I can't find anything that compares vertical hydroponic farming to greenhouses, all I can find relates to CO2 dosing in greenhouses :/
It's less helpful in already highly agricultural nations like the US, but in countries with scarce arable land or fragile ecosystems, or just very small countries like Singapore/Cambodia, vertical farming is superior to greenhouses simply due to square footage
The economics only make sense for specialty things like fresh greens, micrograms, mushrooms, etc. That can't be farmed at a consistant high quality year round or be stored. It will never be economical for 80% of food.
I believe greenhouses and vertical farming are orthogonal. IOW, you can have a vertical farm inside a greenhouse, or a "horizontal" farm inside warehouse with grow lights.
I disagree based on the trends, especially in the US where few, if any, new coal plants are being built and most existing ones are scheduled to be converted to natural gas or shut down. But let's assume that a significant amount of coal will continue to be burned over the next 20 years. Do you think we should stop innovation in other sectors until we are off coal?
Most innovation doesn’t need massive amounts of electricity. EV’s being the only notable exception, but they are also offsetting significant CO2 emissions.
Further, the amount of electricity generated by fossil fuels is going to be heavily dependent on overall electricity demand. Keeping older less efficient and more expensive power plants operating is very much a response to electricity demand not an inherent lifespan independent of the electrical market.
I don't think grow lights in this area are coal powered.
I could see how you might think that because..Wyoming. But I assume hydro and wind, based on the power around me. I'll ask them to confirm. I don't think I'd support coal powered hydro.
I looked it up and Wyoming consumes a lot of coal (according to eia.gov). I don't know about your specific location, but statistically there is going to be a large percentage of coal in that energy mix.
For what it is worth, a tomato truck carries 50,000lbs of tomatoes from the field to a processor. Supply chains are complex, but refrigerated semis can carry a similar load of processed vegetables.
Co-Grow! Use the heat, light and CO² from the power plant directly to power the (growth of) plants, by arranging them around the fire. Use some technomagical glass boiler for that.
Solar + storage is now the cheapest option in the US.
Centralizing energy needs the way vertical farms do, incentivizes the company operating the farm to opt for the cheaper option and install solar on nearby land.
Also, it isn't trucked in from Salinas Valley CA which is 1,000 miles away.