The paradox of vertical farming

Artificial lighting saves land because plants can be grown above each other, but if the electricity for the lighting comes from solar panels, then the savings are canceled out by the land required to install the solar panels.

@neauoire but with high enough efficiency you get to run multiple story high farms from a single panel

@neauoire plus the fact you yield produce all year round, unlike traditional farms

@neauoire i think really the best selling point of solar+vertical farming would be solar panels overlapping existing buildings in cities, with localised small scale vertical farms within those cities, freeing up a ton of infrastructure that we use for transfer and harvest and limitations that had with it. Though currently solar doesn't have great efficiency to surpass the tradeoff, there's some almost 50% efficiency panels in research, which would almost make it a 1:1 trade in m^2 on a good day

@neauoire on the other hand, electricity is a lot easier to move than plants so if you can put the panels out where density isn't a problem and the farms near the people needing the food, you're possibly still better off.

@ndpi You mean like installing panels around the equator to power the farms near the poles?

@neauoire that's pretty large scale! I was thinking put the panels a few tens-to-hundreds of kilometers outside of a city and the farms inside.

@neauoire @ndpi Replacing many km² of tomato greenhouses in southern Spain which truck their produce to northern Europe with PV panels feeding HVDC connections to vertical farms further north might be a net win on a number of axes: overall productivity increase, transport emissions reductions, working conditions (lot of near slave labour of African immigrants currently) and quality of fruit delivered.

@neauoire @ndpi Supermarket tomatoes in the UK are awful now: red but under ripe, thick skinned with a watery middle and no flavour as they're selected to look good on the supermarket shelf after they've been trucked from Spain. Local production from local wind power and HVDC PV could allow much shorter trips from “farm” to store so much better quality.

@edavies @neauoire it was interesting seeing all the greenhouses in Iceland growing fruits and veggies using geothermal power. I imagine we could do something similar with other sources in northerly regions.

@neauoire I'm typically not one to complain about recreating nature but this is a fair point. You also have to calculate the energy and waste impact of the solar panels themselves. Imo hydroponics/vertical farming doesn't usually make sense where there is plenty of sun available.

@neauoire what about crops that grow with less sunlight than is in the area? The artifical lighting could be less powerful that the sunlight, and the excess power from the solar panels could power other things. Or the farm could be built taller with less area on the surface used by the panels than would be used by the crops.
@neauoire solar is so inefficient, i can't imagine PV-based vertical farming even becoming viable. if you have nukes or hydro power available, that's a different story.

@neauoire In a city center with solar panels on roof tops and then centralized plant farms you may gain some efficiency.

The alternative being someone going up to every roof top to care for / harvest the plants?

@rune the alternative might be something like a garden on every roof yeah.

@neauoire I think it would be easier to get people to install solar panels than getting them to care for a garden (if one can even be setup on their roof).

I also think you can do it more efficiently if you centralize it a bit.

But I absolutely recognize that it complicates things and has some downsides.

@neauoire @rune or what about a solar collector/concentrator on a tall building that distributes into a farm within that same building underneath? 🤔

@neauoire vertical farming is a joke. You can't grow anything worthwhile in there except lettuce, tomatoes, other microgreens, and herbs.

@neauoire I'm not so sure this is true. I can't find true apples to apples numbers to do the math. Chlorophyl only captures 6% of solar energy. If the solar panel absorbs all frequencies and then powers LEDs at specific frequencies then you could come out ahead this way. There's also an additional advantage in the desert. All that extra sun will drive off moisture but the panel can handle it.

@neauoire Mirrors? Lightpipes?

In the long run, we'll inevitably have to build that Dyson sphere!

@neauoire The other benefits arise from not dumping pesticides and fertilizer directly into the water system, as well as being weather agnostic. Most of these vegetables/greens would come from Mexico or California otherwise out of season.

Individual gardening, especially in urban environments, won't provide enough food to sustain those who grow it, particularly those with winter.

Nonetheless you still can't do stable grains in vertical farms. So its kind of moot.

@neauoire the panels may be placed on land (or sea or whatever) that couldn't be used for farming otherwise, though. Or be on top of built up areas that are already not used for farming. It's not quite zero sum

@neauoire and then the replies loaded and I saw a hundred copies of the same 🙃 sorry for adding to the noise

@neauoire I'd imagine transporting electricity, from the solar plant in the desert, to the vertical farm near the cities where that food is consumed, would be advantageous compared to using big trucks to carry unripe fruits over long distances.

@pindola You'd also have to transport the water, and create artificial wind, and somehow bring pollinators(maybe?).

The solar panels could go closer to the sun, like in space too. By the time we get to mass vertical farming, we will get to solar panels in space too.

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