Seawater Greenhouse (2017) | Hacker News Reader

Seawater Greenhouse (2017)

seawatergreenhouse.com

67 pointszeristor22 comments

Sundrop Farms [1] built a 40Ha seawater greenhouse facility in Australia with investment from KKR. They managed to get multi-year fixed pricing due to the undersupply of quality tomatoes in the region. This is pretty much unheard of in the industry. The facility was sold in 2019 [2]. The original inventor is a fellow British fellow, Charlie Paton [3] - he's a great guy and helped us get to know the greenhouse industry when we were starting out.

A lot more high-tech greenhouses need to be built. They are a great solution for supplying high-quality, locally-grown food, with minimal pesticides and resilience to extreme weather caused by climate change. They have the same benefits as vertical farms but with higher efficiency - especially for crops like tomatoes and berries.

Shameless plug: At Optimal, we are solving the barriers to scale for high-tech greenhouses. Our team has deep expertise in greenhouse horticulture and machine-learning/optimisation/control/software.

Find out more about what we're doing here: youtu.be/LDJ_QdUaap4

Team: https://www.linkedin.com/company/optimal-labs/

Contact me (founder) directly if you want to know anything about this fascinating way of growing: david@optimal.ag

[1]: https://www.sundropfarms.com [2]: https://www.freshplaza.com/article/9104623/new-owners-for-su... [3]: https://seawatergreenhouse.com/team

Hey there, FYI on your careers page the "Overseas applicants" button just opens the same page in a new tab.

Sorry about that. We're using AngelList as our careers page and it's clunky. We're about to change it. In the meantime please reach out to me directly on david@optimal.ag.

Very interesting, I was going to do something very similar, I've sent you an email.

Other commenters have noted that this project seems to have folded years ago. It thus completes the circle of tech-forward ag projects: A huge upfront investment, followed by a press blitz, followed by a runway of varying length that leads to the ultimate scrapping of the project for parts.

It's really attractive to think we're just a vertical farm or a novel greenhouse away from an agricultural revolution. But as much fun as is to grow things where they don't normally grow, one isn't competing against an empty patch of sand. The competition is the entire global food supply, complete with its brutally efficient transportation networks.

(The usual rebuttal is that these sorts of systems are only for leafy greens and vegetables. Which are nice to have, but not really key to sustaining a population. I’ve noticed that a lot of Youtube gardeners do this handwaving as well. It’s like, “I feed my family of four from my 1 acre farm!” Neglecting to mention that they only grow zucchini and 95% of their calories come from the grocery store.)

Sorry to sound salty (heh) about this, but the Hard Problems of agriculture are extremely hard. The people who succeed as farmers do so in spite of tiny margins and enormous operating costs. They're more innovative than most people in the tech world.

What is the evidence that this has folded?

I have seen no evidence to confirm that?

Mention has been made of a satellite image, but unless the image is dated it is of scant validity.

Brine utilisation for cooling and salt production in wind-driven seawater greenhouses: Design and modelling

Abstract:

Brine disposal is a major challenge facing the desalination industry. Discharged brines pollute the oceans and aquifers. Here is it proposed to reduce the volume of brines by means of evaporative coolers in seawater greenhouses, thus enabling the cultivation of high-value crops and production of sea salt. Unlike in typical greenhouses, only natural wind is used for ventilation, without electric fans. We present a model to predict the water evaporation, salt production, internal temperature and humidity according to ambient conditions.Predictions are presented for three case studies: (a) the Horn of Africa (Berbera) where a seawater desalination plant will be coupled to salt production; (b) Iran (Ahwaz) for management of hypersaline water from the Gotvand dam; (c) Gujarat (Ahmedabad) where natural seawater is fed to the cooling process, enhancing salt production in solar salt works. Water evaporation per face area of evaporator pad is predicted in the range 33 to 83 m3/m2·yr, and salt production up to 5.8 tonnes/m2·yr. Temperature is lowest close to the evaporator pad,increasing downwind, such that the cooling effect mostly dissipates within 15 m of the cooling pad. Depending on location, peak temperatures reduce by 8–16 °C at the hottest time of year.

https://publications.aston.ac.uk/id/eprint/31704/1/Brine_uti...

[Edited for link to pdf paper, and abstract]

Here it is on Google Maps-

https://www.google.com/maps/place/Berbera,+Somalia/@10.40436...

If you are feeling cynical you can pull it up on Google Earth and flick through time.

Somaliland is now effectively a nation in its own right and over the last couple decades has been generally more peaceful than Somalia, although international recognition is lagging.

That is so sad to see. It reminded me of this one wood that was planted in then desert. You could see it dried out and then later cut down.

I'm surprised they aren't growing hydroponically in such a water-constrained environment, as the water use is lower. I guess it is due to the difficulty in getting the nutrients to somaliland?

As talked about in this podcast:

https://www.bbc.co.uk/programmes/w3cszv2l

Thanks for posting the link to this podcast! I enjoyed listening to it. It seems the situation is not as bad as Google Earth would have you believe - stuff got torn down in a storm but they are planning to rebuild it.

One thing that caught my ears was the short snippet when they talk about about how the men in the region are looking down upon farming... smells sort of like a "startup opportunity" to me.

There are others using solar desalination e.g. https://www.researchgate.net/figure/The-seawater-greenhouse-...

Think there are some in Morocco and Tunisia too

I love the low-tech solution to the problem! Not much more to say, I just think it's a great a solution that will go a long way to both helping the people in this area of Somaliland, and serving as a template for similar projects in other regions of the world.

I'm curious what the life expectancy of the cardboard evaporators are, I'd have guessed they would either mold over or just fall apart from being soggy all the time. Color me surprised.

In the several years I worked on a non-climate controlled manufacturing floor, we never replaced the cardboard in our evaporative coolers[0]. We added a quaternary amine-based cleaning agent every so often to knock out the mold.

0: https://www.mcmaster.com/2073K37/

Concentrations of salt of 3.5 percent or higher tend to kill mold. So that should help significantly.

I'm curious how quickly lime etc will clog the cardboard.

I have an evaporative humidifier, and it has a similar filter. Every couple of months I throw it away and put in a new one, because its turned into a solid block of lime.

so, how does this look 4 years later?

Dead. There is a comment further down, where you can see the state of it in Google Maps.

I recommend listening to this podcast, it seems might not be totally dead there after all. Podcast was released yesterday and they talk about rebuilding it: https://www.bbc.co.uk/programmes/w3cszv2l

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