Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

What vertical farming and ag startups don't understand about agriculture

thinkingagriculture.io

Post reply on HN
Print view View original

271–280 of 321 posts

Re: What vertical farming and ag startups don't understand about agriculture

#271

Post by mahaganapati »

gen220 wrote: post #238
alisson wrote: post #189

Earlier quoted context omitted.

They are very similar actually, but permaculture is about more than just agriculture, agriculture is one of the sides of permaculture. For me syntropic agriculture is that side, some people also call it agroforestry but this term is used for other kinds of agriculture, which builds forests but differently. On syntropic the main difference is very high density of plants and extensively pruning. The video I posted in t…

Introducing an idea, in case you haven't encountered it elsewhere already. There are some estate-farms in England that are arriving on the same conclusion of permaculture/syntropic ag, albeit from a different angle. They were spending a lot of money to extract marginal agricultural products from soil that wasn't well suited to monoculture, and some eccentric estate managers decided to stop spending the money, and all…

That's very interesting and useful, thank you for sharing

Re: What vertical farming and ag startups don't understand about agriculture

#272

Post by coder543 »

saeranv wrote: post #263
bilbo0s wrote: post #261

Earlier quoted context omitted.

Hmm. If the target is 1MWh in a year, that seems trivial to deliver in a place like Chad. Insolation in Chad should be right around 6 or 7 kWh per sq metre. [0] Chop off 85% of that, because we can't harvest all of the solar energy that falls on a square metre of land. We can only reliably capture maybe 15 to 20% of it. But even if you harvest that 1.5 kWh for only 4 hours a day, (which is pretty easy in the middle o…

Solar panels themselves are only 10% - 15% efficient at converting solar to electricity. So I think your estimate here is off by a factor of 10.

If you google “solar panel efficiency”, you will instantly find several sources that all indicate that most (cheap!) solar panels are 15% to 20% efficient, which is 50% higher than the number you’re providing. Top end residential solar panels are over 20% efficient, somewhere in the neighborhood of 22%. Specialized/research solar panels can reach efficiencies of over 40%.

Also, energy density is not nearly as important as you seem to fundamentally believe. It’s pretty much all about cost and availability.

In countries that use very little energy per capita, even just a single solar panel (with a small inverter and a lead acid battery) per person (or even per family) is life changing, giving them enough energy to run a small refrigerator, a light bulb, and a place to recharge their smartphone without having to go into town and pay someone.

In deep urban environments, space is definitely at a premium, but I struggle to imagine that many people are excited to set up a dirty diesel plant in the town square when air quality is already bad enough due to heavily polluting vehicles running in the city center, let alone set up a small nuclear plant, even if wealthier countries would allow such a proliferation of nuclear technology and fuels. Once the nuclear fuel is spent, then you have this extremely toxic, dangerous waste that has to be put somewhere, and those people probably have a lot of other things on their minds, so you could just be rad poisoning their town by giving them nuclear if they don’t dispose of the waste properly.

On the other hand, the rooftops are prime locations for solar panels and solar water heaters, and because 175W/m^2 of solar converted electricity is actually a ton of energy, it’s still plenty of power.

Unfortunately, cost and availability are king. Wealthy countries are happy to sell old assets at a steep discount, and so shiny new solar panels have to compete with second hand fossil fuel plants / generators that don’t lend themselves to great air quality.

Solar is an extremely sensible solution. Nuclear is not a clear answer at all for developing countries, unless you happen to have the design for a clean, portable cold fusion reactor in your pocket. Fission has a lot of problems that are manageable, but managing those problems takes significant money.

Re: What vertical farming and ag startups don't understand about agriculture

#273

Post by ineedasername »

kumarski wrote: post #158

My father is an ag soil chemist of 50+ years. I'm an industrial systems eng. w/ a specialty in polymer-textile-fiber engineering. (Mostly useless skillsets in the US now) Gonna share a few lessons here about agriculture that I try to convey to EECS, econ, Neuroscience, and the web developer crowd. - You can only grow non-calorically dense foods in vertical farms - It takes 10-14 kwh/1000 gallons of water to desalinat…

What is it about vertical farms that prevents calorically dense foods? Also, I know something like lettuce would not be dense, potatoes probably dense, but is there a cutoff/metric, e.g., calories-per-gram for this determination?

Thanks for the insights!

Re: What vertical farming and ag startups don't understand about agriculture

#274

Post by Brajeshwar »

newyankee wrote: post #165
Brajeshwar wrote: post #11

About two years ago, I started with a much fancier AgTech with Hydroponics. Went all the way to the YCombinator interview in Mountain View (the last one for Indians), and rejected with something in the lines of "not advanced enough". Spent time researching, talking, and more researching about the core problems of Agriculture in India. It is one sector where everyone loves to toss and play around, the most politically…

Would be happy to connect to discuss more. There are plenty of opportunities in India for improvement, it is just that is a complicated market. The humanity improvement aspect here is bigger than the financial one for sure. The only way to start is with something that works low tech and cheap enough for average farmers to get into.

Sure. My profile has connection details.

Re: What vertical farming and ag startups don't understand about agriculture

#275

Post by manicdee »

primroot wrote: post #213
kumarski wrote: post #158

My father is an ag soil chemist of 50+ years. I'm an industrial systems eng. w/ a specialty in polymer-textile-fiber engineering. (Mostly useless skillsets in the US now) Gonna share a few lessons here about agriculture that I try to convey to EECS, econ, Neuroscience, and the web developer crowd. - You can only grow non-calorically dense foods in vertical farms - It takes 10-14 kwh/1000 gallons of water to desalinat…

> You can only grow non-calorically dense foods in vertical farms Purslane (Portulaca oleracea) grows on the sidewalk already, and often next to some wild amaranth (Amarathus Hybridus). What is the point of more efficiently producing specific crops, when there are all these underutilized nutritious plants growing without any human input (or should I say growing despite human input)? This is another problem that I see…

The human input is providing the moisture trap (the concrete lid on the ground preventing water vaporising into the air), so of course plants will thrive there once the level of lime leeching out is low enough to be tolerable.

But in the end you have several tons of concrete covering tens of square metres of ground, to allow one or two square metres of cereal grains to grow. That is not particularly efficient use of time or resources.

Re: What vertical farming and ag startups don't understand about agriculture

#276

Post by westurner »

cheerlessbog wrote: post #269
tathougies wrote: post #237

Earlier quoted context omitted.

Actually no not really. Plants only absorb two wavelengths of light. It's currently more efficient to convert sun into solar power via panels and then to light LEDs supplying only the wavelengths that plants use. Despite the seeming inefficiency here, the fact is that plants are even more inefficient at absorbing light not at the right wavelengths than solar panels.

Could one imagine a material that would absorb solar spectrum and emit the preferred frequencies? Something like a polymer one could stretch over fields to get more from the suns rays.

>> "Actually no not really. Plants only absorb two wavelengths of light. It's currently more efficient to convert sun into solar power via panels and then to light LEDs supplying only the wavelengths that plants use. Despite the seeming inefficiency here, the fact is that plants are even more inefficient at absorbing light not at the right wavelengths than solar panels."

> Could one imagine a material that would absorb solar spectrum and emit the preferred frequencies? Something like a polymer one could stretch over fields to get more from the suns rays.

Would you call that a "solar transmitter"?

https://en.wikipedia.org/wiki/Transmitter :

> Generators of radio waves for heating or industrial purposes, such as microwave ovens or diathermy equipment, are not usually called transmitters, even though they often have similar circuits.

Would "absorption spectroscopy" specialists have insight into whether this is possible without solar cells, energy storage, and UV LEDs? https://en.wikipedia.org/wiki/Absorption_spectroscopy

(edit) The thermal energy from sunlight (from the FREE radiation from the nuclear reaction at the center of our solar system) is also useful to and necessary for plants. There's probably a passive heat pipe / solar panel cooling solution that could harvest such heat for colder seasons and climates.

Also, UV-C is useful for sanitizing (UVGI) but not really for plant growth. https://en.wikipedia.org/wiki/Ultraviolet_germicidal_irradia... :

> UVGI can be coupled with a filtration system to sanitize air and water.

Is that necessary or desirable for plants?

https://www.lumigrow.com/learning-center/blogs/the-definitiv... :

> The light that plants predominately use for photosynthesis ranges from 400–700 nm. This range is referred to as Photosynthetically Active Radiation (PAR) and includes red, blue and green wavebands. Photomorphogenesis occurs in a wider range from approximately 260–780 nm and includes UV and far-red radiation.

Photomorphogenesis: https://en.wikipedia.org/wiki/Photomorphogenesis

PAR: Photosynthetically active radiation: https://en.wikipedia.org/wiki/Photosynthetically_active_radi...

Grow light: https://en.wikipedia.org/wiki/Grow_light

Are there bioluminescent e.g. algae which emit PAR and/or UV? Algae can feed off of waste industrial gases.

Bioluminescence > Light production: https://en.wikipedia.org/wiki/Bioluminescence#Light_producti...

Biophoton: https://en.wikipedia.org/wiki/Biophoton

Chemiluminescence: https://en.wikipedia.org/wiki/Chemiluminescence

Electrochemiluminescence: https://en.wikipedia.org/wiki/Electrochemiluminescence

Quantum dot display / "QLED": https://en.wikipedia.org/wiki/Quantum_dot_display

Could be possible? Analyzing the inputs and outputs is useful in natural systems, as well.

Re: What vertical farming and ag startups don't understand about agriculture

#277

Post by s1artibartfast »

AndrewOMartin wrote: post #223
s1artibartfast wrote: post #160

Earlier quoted context omitted.

Or think that every pistachio that goes to market has been visually inspected and individuals sorted, and has been for the last 25 years. https://www.youtube.com/watch?v=PqK5667B5As

Did you mean to post a link to a YouTube video demonstrating that? Your link is a dupe of the parent.

Thanks for letting me know

Re: What vertical farming and ag startups don't understand about agriculture

#278

Post by jamiek88 »

saeranv wrote: post #262
m3047 wrote: post #251

Earlier quoted context omitted.

I'm not going to provide a source, but my understanding is that one square meter can provide roughly 1 KW of electricity at noon on the equator. Looks like that's about 4MW per acre. Five acres for the "traditional" family farm. I bet where I live that irradiation equals 1MW per acre, and of course it varies seasonally. Sounds ridiculous, until you've tried to water any sizable amount of square footage, and contempla…

1 KW sounds high to me. Granted I work in higher latitudes (42). Rule of thumb is 1KW for peak solar radiation, which translates 100W from a solar panel (which are 15% - 20% efficiency).

And the sun in eight light minutes away. The sheer power is mind boggling.

Re: What vertical farming and ag startups don't understand about agriculture

#279

Post by nradov »

logicNSci wrote: post #222
nradov wrote: post #190

Earlier quoted context omitted.

There is a lot more to medicine than just math and science. That is not a sound basis for criticizing the field. You'll have to do better than that.

>There is a lot more to medicine than just math and science This is the problem.

That is not a problem. It's simply a fact that you'll have to accept.

Re: What vertical farming and ag startups don't understand about agriculture

#280

Post by elcritch »

trophycase wrote: post #175
kumarski wrote: post #158

My father is an ag soil chemist of 50+ years. I'm an industrial systems eng. w/ a specialty in polymer-textile-fiber engineering. (Mostly useless skillsets in the US now) Gonna share a few lessons here about agriculture that I try to convey to EECS, econ, Neuroscience, and the web developer crowd. - You can only grow non-calorically dense foods in vertical farms - It takes 10-14 kwh/1000 gallons of water to desalinat…

I guess I was always under the impression that vertical and urban farming would be done for "specialty" crops like herbs or kale or something, never for high volume cash crops like potatoes or corn. I can see a benefit for these "specialty" crops because they aren't done to the same scale (maybe I'm wrong about that)

The parents comment certainly is accurate for most staples, cereals, and even meat (raised on corn) but entirely misses the need for more fresh veggies and leafy greens in the US. In the states it generally costs more to buy food made with fresh vegetables. That’s where indoor and vertical ag shines. Many developed countries have plenty of empty calories. Too many. Indoor Ag provides an opportunity to provide scale and freshness to a number of non-grain foods, with less pesticides and preservatives. I hope the field is successful at that goal.
Post reply on HN