
Old coal mines can be underground food farms - zeristor
https://www.bbc.co.uk/news/uk-wales-46221656
======
yholio
Coal mines are exceptionally dangerous places. They require constant
ventilation against methane accumulation and pumping out water that seeps in
all the time. The soil is friable and there is a careful trade-off between
personel safety and resources invested into consolidation and securing the
galleries against collapse.

A mine is not some kind of free underground cave, it's an industrial
installation requiring constant engineering. They have 24/7 command centers
that monitor and correct safety parameters before anyone is allowed to go in.
When mines close, they are flooded, refilled or sealed, to prevent underground
explosions and collapse that could kill people above. The closure of mines is
itself a dangerous and expensive operation.

Bottom line, if it ain't worth going down there and picking unlimited
quantities of coal worth $70/ton, it most certainly isn't worth it to invest
and labour for months in a high risk environment, only to get limited
quantities of agricultural produce worth $200-$300/ton.

~~~
chokma
In addition to the dangerous environment, it's also likely to be contaminated
with a lot of toxic stuff. In the closed German coal mines the pumps have to
run 24/7 to prevent both the rising water from flooding the region* and the
flame retardants and other poisons from reaching the surface waters.

* some areas like the city of Essen have dropped by 16m, others up to 40m due to mining. Running the pumps to prevent flooding is considered part of the Ewigkeitskosten (eternal costs, see: [https://de.wikipedia.org/wiki/Ewigkeitskosten](https://de.wikipedia.org/wiki/Ewigkeitskosten) ).

edit: fixed numbers, added link

~~~
porker
> and the flame retardants and other poisons

What did they do with the flame retardants? Spray parts of the mine with them?

~~~
nine_k
A lot of things in a mine is made of wood.

~~~
fencepost
Even worse, a lot of things in a coal mine are made of coal or are covered in
coal dust. Flammable powders can be ugly, particularly if they're floating.

------
netcan
If startup-ey media is anything to go by, agg-tech has some weird ideas about
what the problems are with aggriculture.

The water and land required for vegetables farming isn't a problem. We don't
need to move lettuce production into buildings, mines or submarine farms.

Most of the water & land is used for cereal farming.

Whatever you can grow in a mine or a skyscraper can be grown on a "small" farm
near a city. Whatever water saving, pesticide minimizing, or other benefits
you get have little to do with location.

There are plenty of led/hydroponic farms in normal farming places.

~~~
ryanmercer
>We don't need to move lettuce production into buildings, mines or submarine
farms.

Food crops in general absolutely, some like lettuce could actually benefit
from being done indoors though as you could limit exposure to things like E.
coli compared to traditionally grown lettuce.

Growing in a largely enclosed system also allows you to prevent runoff, use
the least amount of water possible, control all environmental variables etc
BUT unless we suddenly develop fusion today and magically start bringing
hundreds of fusion plants online a year, using the sun is always going to be
more efficient than grow lights.

~~~
Retric
Economically that’s true, but ignoring capital costs...

LED’s are up to 50% efficient. The best Solar is hitting 44% effecency. So, we
can only keep ~22% of the energy from sunlight. However, plants are green
because they only absorb a subset of sunlight. So, by designing LED’s that
only emit the light best collected by plants you can get fairly close to 1:1
and theoretically you could see a net gain. Thus, 100 years from now things
might flip. Further, we can stick solar panels many places we can’t effecently
farm.

It’s still going to stay very niche, such as producing ultra high grade
produce for high end restaurants.

~~~
namlem
We could potentially supplement the LEDs with fiber optics that deliver
natural sunlight underground.

------
NeedMoreTea
10% of the entire UK's area available in mines? That seems a tad on the high
side at first glance.

No mention of flooding, collapse and the many seams that were well under 6'
high. I remember claims that many mines would be inaccessible thanks to
flooding and collapse within days of closure during all the mine closures of
the 80s. No idea how much of that was hype to try and avoid closures of
course.

So what percentage is worth opening up again for possible agriculture? Based
on the photo of two chaps using an old shelter the size of a poly tunnel, very
very inefficiently, barely any.

Seriously, having seen commercial poly tunnels, I'd expect to have the staging
shown but wide enough that a human can only just squeeze down the centre path,
_and_ another level, _and_ the entire floor area allocated to growing as well.

I'm gonna need a bit more convincing on this. :)

~~~
arethuza
Here is a link to the UK Coal Authority interactive map:

[http://mapapps2.bgs.ac.uk/coalauthority/home.html](http://mapapps2.bgs.ac.uk/coalauthority/home.html)

There are a _lot_ of old mines in the UK!

[NB I found out about this when researching buying a house outside of
Edinburgh - we ended up getting a house near an old limestone mine in Fife
although where our house is it's volcanic rock with no mine workings under
us].

Edit2: In case anyone is wondering here is a geology map viewer for the UK:

[http://mapapps.bgs.ac.uk/geologyofbritain/home.html](http://mapapps.bgs.ac.uk/geologyofbritain/home.html)

~~~
nmeofthestate
Interestingly you can see mining used to stretch under the Firth of Forth
between Lothian and Fife. Supposedly, back in the day, the tunnels linked up
and you could have walked from Fife to Lothian via the mine workings.

This idea in the article seems like utter nonsense, and the fact that it's in
an article on a reputable website doesn't give me any confidence it isn't.

~~~
shaki-dora
> Firth of Forth between Lothian and Fife

I have no idea what (who? Where?) this is, but now I want to conquer it/ask
them out for dinner.

~~~
arethuza
[https://en.wikipedia.org/wiki/Firth_of_Forth](https://en.wikipedia.org/wiki/Firth_of_Forth)

It's an area thick with history from before the Romans to more recent times.
One example:

[https://www.bbc.co.uk/news/uk-
scotland-46273928](https://www.bbc.co.uk/news/uk-scotland-46273928)

~~~
davrosthedalek
Is that somehow related to Genesis' Firth of Fifth?

------
camtarn
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.

~~~
zrobotics
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
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.

------
walrus01
Just about the only ex mines which are useful afterwards are salt mines, some
of which are used for climate controlled storage facilities or data centers.
Not coal mines.

And the occasional hard rock nickel mine, one of which was repurposed into the
Sudbury neutrino observatory.

~~~
retzkek
The Sanford Underground Research Facility is in the former Homestake gold mine
in South Dakota. [https://www.sanfordlab.org/](https://www.sanfordlab.org/)

Work recently began to prepare the facility for the massive DUNE neutrino
detectors, which will be to neutrino physics what the LHC is for high-energy
physics. [http://www.dunescience.org/](http://www.dunescience.org/)

------
sesm
Dwarf Fortress players have known this for over a decade

~~~
rtkwe
Given how badly most of those games end I'm not sure I'd look for designs
there.

------
muriithi
When I see all these high tech plans to grow food in developed countries, I
always wonder how developing countries who sell food to developed countries
will get reliable markets.

But then again no one owes poor countries a decent livelihood.

~~~
ryanmercer
> I always wonder how developing countries who sell food to developed
> countries will get reliable markets.

They'll stop growing specialty stuff for export and start growing a more
diverse range of crops and sell them domestically which will lower food prices
and should benefit their economies in the long run.

The US exports 40% of the corn it grows, uses another 20% for ethanol
production but we import 40% of our fruits and 20-something percent of our
vegetables. We also exports absurd amounts of other grains. If we grew most of
our crops for domestic use and stopped importing tropical and out of season
fruits and vegetables, we'd have much more sustainable farming practices, less
waste, considerably smaller carbon emissions from all the importing and
exporting, etc.

Go to your grocery, you'll see mounds and mounds of bizarre looking alien pods
which are allegedly fruit and vegetables from far off lands. I can't possibly
imagine they sell even 50% of what the stores receive because most people
simply have no idea what it is or how to prepare it.

Hell, I have problem finding sweet peppers that are molded and/or aren't
wilted leathery looking things when I go to the grocery each week. Week after
week, store after store, without fail. That's waste and none of it is grown
domestically (mostly Mexico although occasionally the stores near me will have
stuff from South America).

~~~
ryanmercer
*aren't molded

------
onemoresoop
For plants growing in vertical shafts, it seems to me that plants will have to
get used to grow somehow horizontally or at an 90 angle (last 2 figures in the
article [0]). How would that be possible? I think this may come to a
misunderstanding and an oversimplification of this technique and plants would
still grow vertically and upwards.

[0]
[https://ichef.bbci.co.uk/news/624/cpsprodpb/76A1/production/...](https://ichef.bbci.co.uk/news/624/cpsprodpb/76A1/production/_104596303_a5ede59c-809f-4485-a554-04ce0ee1e596.jpg)

~~~
dmurray
Most plants are pretty good at growing towards the light. It's not a suitable
way to grow a pine forest, but it should be OK for lettuce.

------
code_beers
Great idea! Why would we grow plants where the sunlight is? Illogical!
Preposterous! Let’s bury them in caves full of toxins and industrial waste,
then grow them using expensive artificial lighting!

------
zeristor
One can only eat so much lettuce and herbs though, I believe they’re the most
economically viable, but grains, and potatoes not so much.

~~~
adrianN
I'd go for mushrooms and yeast tanks in damp dark places. But you can also eat
only so much of them.

------
tbarbugli
Stop eating beef instead of focusing on these BS ideas.

~~~
neaden
Pasture raised cattle, and other grazing animals, can actually be very
environmentally friendly. Properly managed pasture requires very little to no
fertilizer, pesticides, or herbicides and acts as a net carbon sink. It can
also have a large amount of biodiversity. The problem right now is feedlot
style operations, where corn is grown as a mono-culture in one place and then
shipped to a feedlot.

~~~
rtkwe
That's not the system we have though and going to a grazing based supply for
cattle would require drastically cutting back the consumption of beef. Only
about 10% [0] of the world's current beef is supplied through grazing pastures
and that's already stressing grazing areas in suboptimal climates.

[0]
[http://www.fao.org/docrep/x5304e/x5304e03.htm](http://www.fao.org/docrep/x5304e/x5304e03.htm)

~~~
neaden
Definitely true, and I didn't mean to imply that. Just think it is important
to point out that we do have existing ways to sustainability eat beef, though
as you point out it would require cutting back consumption to something more
approaching the historical norm. I just think that grazing animals have an
important role in our food system going forward as we try to make it more
sustainable.

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simon_000666
Err, or you could use them as pumped hydro storage and make all that off peak
renewable energy useful, like most other countries are doing.

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speedplane
Mines are "perfect" farms? I remember hearing once that in order to grow,
plants need this thing called light.

~~~
simonh
Try reading the article. For shafts close to the surface they can use fibre
optics to bring in sunlight, deeper down they use LED lights.

~~~
ben_w
Sunlight is ~1,000 W/m^2. Even accounting for the efficiency boost of only
using photosyntheticaly useful parts of the spectrum, the quoted energy cost
feels off by one or two decimal places.

There is also the point that sunlight is free, and greenhouses already solve
the same problems. The Netherlands already does this to great effect:
[https://www.nationalgeographic.com/magazine/2017/09/holland-...](https://www.nationalgeographic.com/magazine/2017/09/holland-
agriculture-sustainable-farming/)

~~~
simonh
Tunnels have much better and cheaper climate control, easier access to water,
cheaper land costs. It's not necessarily a case of one one single variable
determining the viability of the whole idea especially when this is, as I
said, _covered_ _in_ _the_ _article_.

No idea if this will ever come to fruition, but these people do seem to have
done some homework and have prototypes up and running now.

