
Farm grows vegetables in a desert using sun and seawater - rmason
https://www.newscientist.com/article/2108296-first-farm-to-grow-veg-in-a-desert-using-only-sun-and-seawater/
======
dlss
From OP:

> Sunshine and seawater. That’s all a new, futuristic-looking greenhouse needs
> to produce 17,000 tonnes of tomatoes per year in the South Australian desert

> The $200 million infrastructure makes the seawater greenhouse more expensive
> to set up than traditional greenhouses, but the cost will pay off long-term,
> says Saumweber. Conventional greenhouses are more expensive to run on an
> annual basis because of the cost of fossil fuels, he says

From the #1 google result for "cost of a ton of tomatoes"
[http://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=15889](http://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=15889):

> Processors agreed to pay growers $83 per ton in 2014, up from $70 per ton
> last year.

So assuming _100%_ profit margins (ie the tomatoes grow themselves, no human
labor needs to be paid, nothing needs repairing or replacing, tomatoes deliver
themselves to processing plants, etc, etc), the 17,000 tonnes produced would
yield ~$1.4M annually. That's an awful (0.7%) annual return on $200M. Much
less than you could get by investing the $200M in an index fund.

Which is to say there's a 0% chance it will "pay off in the long-term".

~~~
rusanu
But the infrastructure cost of $200M can go down drastically on subsequent
iterations, think how the cost of solar evolved past 5 years.

I'm thinking at this as proof of concept. If it works, there are many rich
areas of the globe where fertile soil is at a premium and cannot grow much.
Basically, transform oil dollars into local grown food.

~~~
MarkMc
> But the infrastructure cost of $200M can go down drastically on subsequent
> iterations, think how the cost of solar evolved past 5 years

So my $200M inestment will struggle to compete with a $40M investment in 5
years? That is a reason _not_ to invest.

~~~
regularfry
It's a $200M investment to own the company which will be taking $40M off
someone else in a few years time to design and build their farm for them.

------
achow
Seems like this idea is couple of decades in making..

A seawater greenhouse is a greenhouse structure that enables the growth of
crops in arid regions, using seawater and solar energy.

The technology was introduced by British inventor Charlie Paton in the early
1990s and is being developed by his UK company Seawater Greenhouse Ltd.

The technique involves pumping seawater (or allowing it to gravitate if below
sea level) to an arid location and then subjecting it to two processes: first,
it is used to humidify and cool the air, and second, it is evaporated by solar
heating and distilled to produce fresh water. Finally, the remaining
humidified air is expelled from the greenhouse and used to improve growing
conditions for outdoor plants.
[https://en.wikipedia.org/wiki/Seawater_greenhouse](https://en.wikipedia.org/wiki/Seawater_greenhouse)

Making Namibia’s desert green using seawater
[https://www.newera.com.na/2016/07/08/making-namibias-
desert-...](https://www.newera.com.na/2016/07/08/making-namibias-desert-green-
seawater/)

~~~
hyperpallium
> On a sunny day, up to 39 megawatts of energy can be produced – enough to
> power the desalination plant...

They don't appear to be using evaporation and distillation, but instead
generate electricity and run the desalination plant with that... I'm guessing,
by pressured osmosis, as used elsewhere in Australia.

My question is: why don't they do it as you assumed? Whatever a solar still
might lose in efficiency, it must surely make up in the reliability and
simplicity of no moving parts.

~~~
bjelkeman-again
During the pilot project Sundrop decided to simplify the design. The equipment
for the distillation of the hot humid air proved to be complicated to produce
with the resources available at the time and they decided to go with a more
conventional method.

Personally I think the original design could be made to work, but it needed
more R&D than Sundrop was prepared to spend at the time.

~~~
stuaxo
Indeed, trying too many new processes all at once would be setting yourself up
for failure. Now this works, the other parts can be addressed and further
efficiencies made.

~~~
stuaxo
There's a great video on youtube about the Advanced Passenger Train in Britain
in the 80s where they tried a few too many new things with predictable
results.

------
DavidWanjiru
Where are the nutrients for plants coming from?

They say plants are grown in coconut husks instead of soil. Does the coconut
husk act merely as a plant holder, or is it the one that provides the
nutrients that the plant would otherwise obtain from soil (with/without
fertilizer)? That part is not clear to me.

Edit: "There is no need for pesticides as seawater cleans and sterilises the
air..." What does this even mean? Do we normally use pesticides to clean and
sterilize the air? Are the pests that we fight with pesticides eliminated when
the enclosed air in a greenhouse is cleaned and sterilized in this manner?

~~~
crypt1d
> They say plants are grown in coconut husks instead of soil. Does the coconut
> husk act merely as a plant holder, or is it the one that provides the
> nutrients that the plant would otherwise obtain from soil (with/without
> fertilizer)?

The coconut husk is just an inert medium which has good water retention rate.
The nutrients are supplied via water by irrigating the plants frequently or
submerging the roots. The whole method of growing plants like this is known as
hydroponics[0].

[0] If you are interested in hydroponics, this guy has a lot of amazing videos
that explain various aspects of it -
[https://www.youtube.com/user/Just4Growers](https://www.youtube.com/user/Just4Growers)
.

~~~
go_go_
Also, if you're interested in hydroponics (especially indoor) and live within
the US, be careful how you buy the materials needed to start. The police are
known to profile these customers and raid the houses several months later [0].

[0] [http://www.kansascitycriminaldefenselawyer.com/when-
gardenin...](http://www.kansascitycriminaldefenselawyer.com/when-gardening-
warrants-a-swat-raid/)

~~~
soared
Looks like a reliable source to me!

~~~
go_go_
That was just one of the more succinct sources I could find at the time. Here
is an article from the Washington Post which details the subsequent lawsuit
against the police department (which they lost).

[https://www.washingtonpost.com/news/the-
watch/wp/2015/12/28/...](https://www.washingtonpost.com/news/the-
watch/wp/2015/12/28/federal-judge-drinking-tea-shopping-at-a-gardening-store-
is-probable-cause-for-a-swat-raid-on-your-home/)

------
femto
sun, seawater .... and fertiliser.

As made clearer in other articles [1], they are adding nutrients to the water.

In response to delbel: As mentioned in [1], the farm has a 10-year contract
with Coles, one of Australia's big supermarkets, and that was what enabled the
farm to be funded. Consequently, you can go to Coles and buy these tomatoes
for about A$7 per kg. [2]

[1] [http://www.abc.net.au/news/2016-10-01/sundrop-farms-opens-
so...](http://www.abc.net.au/news/2016-10-01/sundrop-farms-opens-solar-
greenhouse-using-no-fresh-water/7892866)

[2]
[https://shop.coles.com.au/online/SearchDisplay?storeId=10601...](https://shop.coles.com.au/online/SearchDisplay?storeId=10601&catalogId=10576&langId=-1&beginIndex=0&browseView=false&searchSource=Q&sType=SimpleSearch&resultCatEntryType=2&showResultsPage=true&pageView=image&supermarketRefer=yes&searchTerm=tomatoes)

~~~
jonknee
> sun, seawater .... and fertiliser. As made clearer in other articles, they
> are adding nutrients to the water.

Yes, that is how plants work.

~~~
ChristianBundy
Why so smarmy? The article specifically says "using only sun and seawater", so
it's worth mentioning that they're also adding nutrients to the water. There
are three necessary ingredients.

If the title was "using only sunlight and nutrients" or "using only seawater
and nutrients" it would make sense to mention the third ingredient, so I'm
confused at why you jumped straight to condescension.

~~~
civilian
IDK, I am with jonkee here. Femto seems like the smarmy one to anyone who has
some knowledge of biology.

It's really weird to be on a HN thread where most of the people don't know
much about the topic, you get really weird pedantic posts seemingly out of
nowhere. Biology and space seem like the most common ones, where people who
are very smart point out missing details, the kind of missing details that are
handwaved by the actual professionals and the kind of details that would turn
an article like this into a textbook chapter.

~~~
femto
A realistic possibility was that they are using the cheap energy to
manufacture nutrients, such as ammonia, on-site, which is an energy intensive
process [1].

[1][https://www.scidev.net/global/agriculture/news/solar-
ammonia...](https://www.scidev.net/global/agriculture/news/solar-ammonia-
process-may-spur-fertiliser-revolution.html)

~~~
lightedman
Another alternative is the seawater they're getting comes loaded with nitrates
already from fertilizer runoff or naturally-occuring sources of nitrate
leaching.

------
pilooch
For those interested in these matters, the books by Masanobu Fukuoka (1) are a
must. They may challenge some of the HN crowd views on progress, technology
and religion, as they did definitely challenge mine, but they carry
significative scientific truths. His focus on fighting desertification was
both genius and ahead of his time.

(1)
[https://en.m.wikipedia.org/wiki/Masanobu_Fukuoka](https://en.m.wikipedia.org/wiki/Masanobu_Fukuoka)

~~~
xkarga00
The One Straw Revolution has been very inspiring for me. Highly recommended to
anyone who wants to learn about natural farming.

~~~
oska
Inspired me so much that I flew to Tokyo, caught an overnight ferry to Shikoku
and then hitch-hiked across the island to visit his farm. Met the man and
spent the day looking around the farm/orchard. It was very beautiful.
Unfortunately he was then too old for me to stay longer (I'd had dreams of
living and working on the farm). This was back in 1990.

~~~
pilooch
Beautiful! If you have pictures and one day blog a few lines about this
encounter, I'd be delighted to read it!

~~~
oska
Thanks for your interest. I should write it up. I also visited an organic
mikan farming co-operative not far from Fukuoka's farm on Shikoku and stayed
there a few days. Actually he suggested it to me.

------
bjelkeman-again
There are several things which aren't covered well in the article. I have
spent quite a lot of time looking at the feasibility of the Seawater
Greenhouse in multiple locations, including a visit to this Australian
location a few years ago. [1] I haven't been involved since the pilot
installation in Port Augusta, so they may have changed a few things described
below.

The Seawater Greenhouse design is not a conventional greenhouse. It cools
rather than heats a crop, it is an open design, rather than a conventional
"closed" design.

The system, as designed by Charlie Paton, uses evaporative cooling in the
greenhouse. Essentially they have a cardboard wall, sort of like a thick honey
comb with holes through it, over which they pour seawater. The air is pulled
through the wall by large relatively slow fans. When the air moves through the
"honey comb" wall, the air changes direction (30 degree angle channels).
Particles and insects in the air essentially get stuck in the seawater.
Seawater is particularly bad for insects and other small pests as the salt
clogs up the exoskeleton and the breathing channels when the water evaporates.

Even though the greenhouse was standing in an area of vegetation with a
significant insect population outside, we hardly saw any insects on the
inside. But you could often find quite a few insects in the seawater tanks
used to hold the water for the evaporators. The stable climate created in the
greenhouse and the seawater "barrier" created by the evaporators means the
pest insect pressure is lie and you can easily control it with natural enemies
(bio control). (There where poisonous spiders in the canopy of the crop but
they don't affect the crop, but act as biocontrol. Just don't let them bite
you.)

Plants grow much better in a cooler and high humidity environment. The plants
don't have to put so much effort into transpiration to keep an acceptable
temperature for photosynthesis. The evaporators with seawater handles both of
those things.

The temperature during my visit peaked on Christmas Day at 43 C, but inside
the greenhouse it was a much more acceptable 35 C. (We had our Xmas dinner
just behind the evaporators, the most pleasant place in Port Augusta at that
point.) The energy used for this cooling primarily comes out of the water and
the surrounding air. Some energy is used for pumping water. Without the
evaporative cooling the temperature in the greenhouse would have been at a
level which would have killed the plants. During my visit the plants and crop
grew so fast that we had to help harvesting to keep up.

The evaporators are also covered by sea salt, which is hydroscopic (absorbs
water) which means that when the temperature drops at the end of the day you
don't get water (dew) collecting on the plants. This is important as dew on
the plants and produce allows botrytis (mold) to grow and potentially destroy
the produce. This also avoids having to burn sulphur in the greenhouse to kill
the mold.

[1] pictures from my wife during the visit
[https://www.flickr.com/photos/ankertje/7044271777/in/album-7...](https://www.flickr.com/photos/ankertje/7044271777/in/album-72157625710401409/)

~~~
russdill
What happens to the concentrated sea water at the end of the cycle? Does it
get pumped back to the ocean? Deposited into the ground?

~~~
pm90
100% natural, environment friendly, organic non-GMO locally produced
Australian salt!

~~~
utternerd
How would one even make genetically modified salt? The most you could do is to
add additional genetically modified compounds to the salt, but salt in and of
itself cannot be genetically modified.

------
rmason
When I saw the headline I knew instantly how they did it. But the one thing
unexplained in the story was their claim that the seawater piped in eliminated
the need for pesticides.

I would bet it was the desert climate that reduced the need for pesticides. I
am willing to predict that they will eventually need to use pesticides.

~~~
proee
if the plants are inside a greenhouse, i think this is a major barrier to most
pests.

~~~
cmrdporcupine
Greenhouses can amplify pest problems as they are a closed system where things
can get crazy very quickly with no natural checks and balances. They are some
of the biggest consumers of pesticides.

~~~
jrapdx3
Growing tomatoes one time under cover had a huge problem with white fly, not
an unusual infestation, but a very stubborn one. While using the natural kinds
may be better, pesticides are often a necessity in that situation. Your
comment was completely on target for many commercial producers.

~~~
niftich
This may turn out to be a silly question, but how does a pest infest a closed
system in the first place? Do they arrive in the soil? Do they fly in the
door?

Could there be ways to mitigate or prevent the mechanism of infestation in the
first place?

~~~
ldp01
I imagine it boils down to a question of expense.

Pests can probably arrive through:

    
    
      - People's boots/clothes.
      - The water.
      - The soil/fertiliser.
      - The air.
    

Each of those inputs would need to be filtered. And the cost of filtration (or
the entry/exit protocols for the workers) would need to be balanced against
the cost of losing a crop.

------
molteanu
In case you missed the article from yesterday, which was also posted here,
named "The Dizzying Grandeur of 21st-Century Agriculture":

[http://www.nytimes.com/interactive/2016/10/09/magazine/big-f...](http://www.nytimes.com/interactive/2016/10/09/magazine/big-
food-photo-essay.html?_r=0)

------
ph0rque
So, this is a hydroponic greenhouse. It would be neat if they went one step
further and made it an aquaponic greenhouse. The use of salt water means they
could consider growing saltwater fish (or shrimp, or fish for caviar). The
only caveat is whether it would be easy to separate the salt from the water
while keeping the other nutrients (nitrogen, etc) in the water for the plants.

~~~
slfnflctd
I don't think it's been settled whether aquaponic setups are any more
efficient overall than hydroponics when you consider all the inputs. A lot of
it would depend on the local environment, the scale of your operation, and the
availability of whatever you're feeding the water critters. It's more variety,
though, which in itself is a nice thing.

~~~
ph0rque
Since this is a commercial enterprise, the question is not one of efficiency,
but of potential profit. You're right that there are a lot of factors that
would play into profitability.

------
foxhop
If this catches your interests, please research greening the deserts using
permaculture.

Here is one example but there are many examples and projects:

[https://www.youtube.com/watch?v=D4Nb-
rqGfWI&spfreload=10](https://www.youtube.com/watch?v=D4Nb-rqGfWI&spfreload=10)
| Reversing Desertification With Sticks, Rocks, and Ancient Wisdom

Permaculture is more practical in the long run, doesn't require much tech.

~~~
schiffern
This. Looking at the headline I half expected this to be a permaculture
installation.

> _I think if we could get Earth in a living and stable state, not a
> constantly degrading and dying state caused by our actions, then we have won
> some right to go to the stars. But at present I don 't think we'd be welcome
> anywhere else in the universe. You wouldn't welcome anybody who'd laid waste
> to their house and wanted to live in yours, I'm sure._ \-- Bill Mollison,
> Co-founder of Permaculture (4 May 1928 – 24 September 2016)

------
mikehines
Perhaps we could colonize the deserts on earth before Mars.

~~~
Hondor
When the next comet strikes, solar powered desert farms will be wrecked just
as much as everywhere else on Earth.

~~~
carterehsmith
Sure, but comet can strike Mars just as easily as it can strike Earth. Maybe
even more easily - gravity, lack of atmosphere, etc.

~~~
DougWebb
That's an interesting idea... I think the thin atmosphere and lack of ocean
might actually make comet strikes on Mars less devastating than on Earth. Less
frictional heating during the impact, no global tsunamis caused by an ocean
strike, much less wind and shockwave around the impact site, faster settling
of post-impact dust and debris. You wouldn't want to be near the impact site
on either planet, but if you're far away on Mars you might barely notice it,
while on Earth you could be on the opposite side of the planet and still be
killed by a tsunami or shrouded in darkness until all the plants around you
are dead.

------
didsomeonesay
> no soil, pesticides, fossil fuels or groundwater

What about fertilisers? I would assume they still use conventional ones made
from fossile fuels. Anybody got more information, did I miss sth in the
article?

------
jrpt
So it's basically a desalination process in a greenhouse powered by solar? I'm
not sure why this is better than leveraging existing infrastructure to get
freshwater and electricity. Also, farming somewhere other than a desert, then
transporting the food to the population (if they live in a desert).

~~~
mastazi
I guess it makes sense in places like SA, NT or WA, where, in 90% of their
territory, all the alternative resources you mentioned are hard to get by.

~~~
bjelkeman-again
There are plenty of economically unproductive coastal deserts in the world
where this could be used.

------
tuananh
Combine with this and we're golden

[http://www.independent.co.uk/news/science/japanese-plant-
exp...](http://www.independent.co.uk/news/science/japanese-plant-experts-
produce-10000-lettuces-a-day-in-led-lit-indoor-farm-9601844.html)

------
pcmaffey
For a headline that explicitly excludes the 3rd essential component of growing
(light, water, nutrients), the article mentions nothing about how these plants
are getting nutrients.

I assume they're supplementing liquid nutrients, as they're growing
hydroponically in coco husks? If so, that makes the headline seem
ridiculous...

The coolest thing in the story for me is using salty air to repel pests.
Though I wonder about the longevity of that solution. I've never seen a
bullet-proof solution to pest control, and especially in self-contained
environments, it's usually just a matter of time. Nevertheless, makes me
wonder about a saltwater humidifier....

~~~
pm90
Salty air is highly corrosive. Unless you want rust in every bit of iron in
your furniture, that may not be the best idea.

------
Nanzikambe
The headline claim is demonstrably poorly researched and as others point out
the project seems to be incredibly poor value.

There's a lower tech approach that's been extensively proven and in production
since 1998, it produces not just veg, but firewood/biomass, shrimps, fish,
fresh water and more:

[http://articles.latimes.com/2001/jan/06/news/mn-9169](http://articles.latimes.com/2001/jan/06/news/mn-9169)
[https://www.youtube.com/watch?v=_P1rPnVUME4](https://www.youtube.com/watch?v=_P1rPnVUME4)

------
ars
This would be awesome for Israel!

And if they could only fix their political problems (to put it mildly) Gaza as
well. It could make a real difference in their future.

~~~
DasIch
Israel has already made huge investments into desalination and has now more
water than it needs.

~~~
ars
More drinking water than it needs, but not more agricultural water - they
could grow a lot more with extra water.

This method could help them do that.

------
EGreg
Wow, simply wow.

Humanity is turning the world into farms, destroying natural forests but then
engineering new types of habitats.

I wonder what the Earth would look like in 200 years.

What I am worried about is the rapid growth of the human population and its
energy use. You can't have exponential growth forever. Most of the issues come
from that. Farms and monocultures sound nice, but are they sustainable? Are
the resources being recycled somewhere, or are we going to be plugging holes
with bacteria digesting plastic and producing plant food?

~~~
35bge57dtjku
> You can't have exponential growth forever.

We don't. Look at the more developed nations.

------
baq
> “It’s a bit like crushing a garlic clove with a sledgehammer,” he says. “We
> don’t have problems growing tomatoes in Australia.”

that's an epic way to miss the point completely.

------
the_watcher
This is fascinating. I grew up about 30 miles from the Salton Sea, which is in
the middle of the desert of Southern California. We get tons of sun. I'd be
very interested if these researchers are communicating with those
investigating how to best clean up the Salton Sea. While those efforts are
still in their infancy, there could be some overlap in application of the
research.

------
donarb
Or instead of wasting energy trying to remove the salt, you could just use
diluted seawater.

[https://www.google.com/amp/s/amp.theguardian.com/science/201...](https://www.google.com/amp/s/amp.theguardian.com/science/2014/oct/18/humble-
potato-poised-to-launch-food-revolution%3f0p19G=e)

~~~
sfifs
Well... you still need to have ready access to fresh-water to dilute seawater.
This experiment is being done in a desert area where fresh-water is likely a
high premium.

------
apendleton
I wonder what they're doing with their desalination outflow? The prine
produced during desalination can be nasty, toxic stuff:
[https://en.wikipedia.org/wiki/Desalination#Environmental](https://en.wikipedia.org/wiki/Desalination#Environmental)

------
dx034
Why do they use concentrated solar power? Isn't that much more expensive and
risky at current prices?

~~~
ndonnellan
That's a good question. Also kind of an interesting side note: the company
behind the solar technology here is not Sundrop, but they're not mentioned at
all. Which I find really curious. I may have worked for that company 4 or 5
years ago. 100 points for whoever can name them!

------
oh_sigh
...and most importantly, fertilizer

(this is covered in the article, but the headline forgets that part)

------
bnolsen
They built themselves a prime bird frying machine. Insects like heat, the
birds follow them and voila, instant cooked meat! Extra bonus for this type
solar.

------
lolive
Solar mirrors need to be extremely clean to be efficient. And that requires a
lot of soap and clean water. Could it be a deal breaker in that kind of
systems?

------
kbart
_" The $200 million infrastructure makes the seawater greenhouse more
expensive to set up than traditional greenhouses, but the cost will pay off
long-term"_

It's really nice experiment, but I don't see how that's gonna pay off. You
need to sell a hell lots of tomatoes to earn _$200 million_ back.

~~~
lolive
Rebrand it as a "Neural-network-AI-assisted seawater greenhouse". And VCs will
fund your 200M$ in a minute.

~~~
kbart
You could've said the same about anything related to "web" in nineties and we
know how it ends, sooner or later. That doesn't make something economically
viable on the long run. I'm all up to self sustained, "green" farming in
impossible places, but 200M$ for a moderate size greenhouse seems way too much
to be something more than an experiment.

------
wodencafe
>First farm to grow vegetables in a desert using only sun and seawater

And Coconut Husks.

------
nikolay
Just becomes something looks like a tomato, it doesn't make it one! In order
to have nutritious produce, you need a lot more than just macro ingredients!

------
maplechori
This should definitely be tried in the UAE!

------
delbel
To pay for the infrastructure, they will probably need to sell the tomatoes
for $100 a pound for twenty years.

~~~
daveguy
Well, the articles states the greenhouse is expected to yield 17,000 tonnes
per year or 37.47 million pounds of tomatoes. The infrastructure costs 200
million dollars. So if they sell the tomatoes for $5.34 per pound they will
pay off the infrastructure in a year. 53.4 cents per pound and they will pay
off the infrastructure in 10 years. I expect it will be somewhere in between.

Pretty close though.

~~~
mikekchar
Edit: Is my price right??? After posting I began to doubt it and I am having
terrible problems trying to find out what the current market prices for
tomatoes is...

Commodity prices are usually expressed in tonnes. It seems at the moment the
price is between $70-$80 per tonne. At $70 per tonne, the price would be about
$1.2 million. You also need to pay operating costs. If the infrastructure is
$200 million, I don't see how they will possibly pay it back. Even at current
low interest rates, I don't think you would be able to pay off your loan.

And yes, commodity prices for food are _ridiculously_ low. _All_ of the money
goes to distributors. Fix that and we can have nice things like this.

~~~
jonknee
But they aren't selling processing tomatoes for commercial use (pizza sauce,
ketchup, etc), they have a contract with a grocery chain for fresh consumer
sales. Amazingly enough it sounds like they ran the numbers before spending
$200,000,000.

~~~
mikekchar
I just figured they had government subsidies. But immediately after posting I
decided that the price seemed wrong. There are some references to California
producers accepting a contract for that amount, but I have to think it is an
error. I can't find a single link for commodity prices of tomatoes.

Maybe as you imply they aren't sold as commodities because the shelf life is
too low.

