4 ms·

Interesting trade-off - much higher energy costs, but on the other hand, mine shafts are probably largely pest-free. No birds, certainly, and probably a much sm

Interesting trade-off - much higher energy costs, but on the other hand, mine shafts are probably largely pest-free. No birds, certainly, and probably a much smaller rate of insect/fungus/mite infection as there's less opportunity for them to be blown in on the wind. The energy costs probably wouldn't be offset by the pest-prevention costs - but it might reduce the damage to the environment, and the increasing fungicide resistance, caused by widespread spraying.

timClicks 8y ago
Also you can grow whatever you want whenever season you want. There's no seasonal variability in temperature or hydration - everything's controlled.
rococode 8y ago
Also, presumably, a big space advantage. Using an existing tunnel network should be easier than having to build a giant building or dig out new tunnels.
- zrobotics 8y ago
  As opposed to the space advantage of just farming on the surface, and not having to dig tunnels or build greenhouses?
  - ivanhoe 8y ago
    And what do you do in winter? In many mountain areas you can't grow sensitive plants unprotected even in summer...
    - logfromblammo 8y ago
      Generally, you place a thermal "fruit wall" poleward of the plants you wish to protect. In winter, the wall absorbs some sunlight, and reflects some onto the plants, while re-radiating heat. The exact angle is determined by prevailing wind direction. The roots get a thick blanket of mulch. If you have enough money, you can then stretch a roll of translucent plastic film from the top of the wall and stake it out to form a lean-to. Or, a light frame can eliminate the need for stakes. (If you're really rich, you can put glass panels in the frame.) Throw a straw blanket over the transparent layer at night, and dangit, now you have a greenhouse, which we were trying to avoid doing. Building an entire field's worth of Chinese-style thermal-wall greenhouses is really cheap, relatively speaking. An unmortared wall made of interlocking compressed-earth blocks will last at least a few years. (Obviously, growing only plants that can survive the local climate without any assistance is cheapest--you just plant the seeds and wait.) Tunneling is a large capital expense. Collapse/subsidence prevention, pumping, and tunnel air management are large ongoing operating expenses. The cost to heat and cool a tunnel, on the other hand, is nearly zero. The greenhouse might need a pile of compost in it to keep it warm enough.
zrobotics 8y ago
How is this at all better ecologically, considering energy costs? The electrical demands to operate a mine are huge, most of which are used in pumping water out of the mine and air conditioning to make the atmosphere breathable. Air conditioning would arguably go up, since it is possible for plants to suffocate themselves with O2 in an enclosed environment. To me, this looks like a far worse ecological disaster than conventional farming unless we develop some form of truly free energy like practical fusion power.
- adrianN 8y ago
  Fusion power is not free. The fuel is relatively cheap, but all the high tech needed to keep the plasma burning needs to be maintained and investments for building power plants need to be recovered.
ivanhoe 8y ago
In cold climate it might not be so much more energy because greenhouses need to be heated in winters and it takes a lot of energy too. For instance 2kW heater is not much, compared to a 2kW light fixture which is like 5 strong led consoles that can grow a lot of lettuce (and also provide enough heating at the same time). If you use rotating stands you can optimize it even more. I think much bigger problem will be controlling the humidity and preventing molds from attacking the plants.
- adrianN 8y ago
  If energy costs were to rise, we could reduce the need for heating greenhouses by a lot if we built them a little smarter. For example you can build greenhouses in northern China, where it gets quite cold, that need almost no additional heating: https://solar.lowtechmagazine.com/2015/12/reinventing-the-greenhouse.html https://solar.lowtechmagazine.com/2015/12/reinventing-the-gr...
arethuza 8y ago
There is a mine ventilation shaft not far from where I live: https://www.geograph.org.uk/photo/765213 https://www.geograph.org.uk/photo/765213 It is very noticeable on cold days that there is a plume of warm moist air coming out of the old workings. Indeed, when I first saw it I thought there must be a fire (although I soon realised what it actually was).

timClicks 8y ago

Also you can grow whatever you want whenever season you want. There's no seasonal variability in temperature or hydration - everything's controlled.

rococode 8y ago

Also, presumably, a big space advantage. Using an existing tunnel network should be easier than having to build a giant building or dig out new tunnels.

zrobotics 8y ago
As opposed to the space advantage of just farming on the surface, and not having to dig tunnels or build greenhouses?
- ivanhoe 8y ago
  And what do you do in winter? In many mountain areas you can't grow sensitive plants unprotected even in summer...
  - logfromblammo 8y ago
    Generally, you place a thermal "fruit wall" poleward of the plants you wish to protect. In winter, the wall absorbs some sunlight, and reflects some onto the plants, while re-radiating heat. The exact angle is determined by prevailing wind direction. The roots get a thick blanket of mulch. If you have enough money, you can then stretch a roll of translucent plastic film from the top of the wall and stake it out to form a lean-to. Or, a light frame can eliminate the need for stakes. (If you're really rich, you can put glass panels in the frame.) Throw a straw blanket over the transparent layer at night, and dangit, now you have a greenhouse, which we were trying to avoid doing. Building an entire field's worth of Chinese-style thermal-wall greenhouses is really cheap, relatively speaking. An unmortared wall made of interlocking compressed-earth blocks will last at least a few years. (Obviously, growing only plants that can survive the local climate without any assistance is cheapest--you just plant the seeds and wait.) Tunneling is a large capital expense. Collapse/subsidence prevention, pumping, and tunnel air management are large ongoing operating expenses. The cost to heat and cool a tunnel, on the other hand, is nearly zero. The greenhouse might need a pile of compost in it to keep it warm enough.

zrobotics 8y ago

How is this at all better ecologically, considering energy costs? The electrical demands to operate a mine are huge, most of which are used in pumping water out of the mine and air conditioning to make the atmosphere breathable. Air conditioning would arguably go up, since it is possible for plants to suffocate themselves with O2 in an enclosed environment. To me, this looks like a far worse ecological disaster than conventional farming unless we develop some form of truly free energy like practical fusion power.

adrianN 8y ago
Fusion power is not free. The fuel is relatively cheap, but all the high tech needed to keep the plasma burning needs to be maintained and investments for building power plants need to be recovered.

ivanhoe 8y ago

In cold climate it might not be so much more energy because greenhouses need to be heated in winters and it takes a lot of energy too. For instance 2kW heater is not much, compared to a 2kW light fixture which is like 5 strong led consoles that can grow a lot of lettuce (and also provide enough heating at the same time). If you use rotating stands you can optimize it even more. I think much bigger problem will be controlling the humidity and preventing molds from attacking the plants.

adrianN 8y ago
If energy costs were to rise, we could reduce the need for heating greenhouses by a lot if we built them a little smarter. For example you can build greenhouses in northern China, where it gets quite cold, that need almost no additional heating: https://solar.lowtechmagazine.com/2015/12/reinventing-the-greenhouse.html https://solar.lowtechmagazine.com/2015/12/reinventing-the-gr...

arethuza 8y ago

There is a mine ventilation shaft not far from where I live: https://www.geograph.org.uk/photo/765213 https://www.geograph.org.uk/photo/765213 It is very noticeable on cold days that there is a plume of warm moist air coming out of the old workings. Indeed, when I first saw it I thought there must be a fire (although I soon realised what it actually was).