As an avid gardener who who got solar panels recently, I've seriously considered looking deeper into this. When I spec'd out my system, I did some back of the napkin math on mining bitcoin with surplus pixies during the day, and it came something on the order of 10x more profitable than what my utility is willing to give me for those same pixies.
However, I don't really use bitcoin. I do however, have an ongoing need for nitrogen fertilizers. I've been digging about into what it would take to drive the Haber Bosch process at a home scale. A couple of 10's of kg of fixed nitrogen a month would be more valuable to me than what my utility is willing to pay, and I could put it right to work in the garden beds.
There are so many alternatives to chemical fertilizer: manure (cow, horse, chicken, human), compost, planting nitrogen fixers, sowing ground cover plants... Depending on where you live each may be easier or harder to produce or procure. In addition there are generative techniques that concentrate on soil fertility: permaculture, cover crops, syntropic agroforestry to name a few. I have never used a chemical fertilizer in my garden, and am striving towards a completely autonomous fertilization cycle, where my garden's fertility grows each year without any external input.
> There are so many alternatives to chemical fertilizer: manure (cow, horse, chicken, human), compost, planting nitrogen fixers, sowing ground cover plants...
Cool. And which of those can I generate using excess electrical energy from my solar panels?
>I have never used a chemical fertilizer in my garden, and am striving towards a completely autonomous fertilization cycle
That is great. I don't have the time or interest in managing animals, and I manage my space for food production because it gives me a sense of control and independence over my food-supply. Over the last 3 years I've imported almost 5000kg of animal manures into my gardens. Its incredibly expensive, and even with that additional fertility, I need more. Its more important for me to have the independence and control over my food-supply than it is to hold to a particular relgiosity around where my N comes from. If I have animal manures, I'll use them. If I have chemical fertilizers, I'll use them. When I have pest issues, I try to use IPM. When that fails, I'll use a pesticide.
Good luck with eating lettuce fertilized with pig/human manure. There is a reason we have health codes. It is the same reason why people in the middle ages boiled all thier food, never ever eating "fresh" vegitables. And if anyone is worried about antibiotics in meat, have a look at how many different drugs are found in human poop. There are a thousand little ancient diseases out there that we in the west have largely forgotten about. Start pooping near where we grow food and they will all start comming back.
Hmm. Very interesting. So many great industrial processes out there that got pushed aside by market forces. I don't suppose they've got a home unit that can run on 120?
>> A couple of 10's of kg of fixed nitrogen a month
And for any other nitrogen uses. Haber-Bosch was originally conceived as a process for making cheaper explosives.
Wikipedia: "Allies had access to large deposits of sodium nitrate in Chile (Chile saltpetre) controlled by British companies. Germany had no such resources, so the Haber process proved essential to the German war effort. Synthetic ammonia from the Haber process was used for the production of nitric acid, a precursor to the nitrates used in explosives."
The Haber-Bosch reaction is exothermic, but requires elevated temperatures, so I suspect that there are significant economies of scale when scaling up the reaction vessel size due to reduced surface area to volume ratio.
Would subscribe to this newsletter if you were to pursue the problem. Have lots of interest in the space but zero of the resources, access to sun, space or chemistry skillset so can only live vicariously on the topic.
In my limited knowledge of fertilizers the larger problem seems to be P and K which are sourced from mined minerals rather than air. It's possible to fix soil N with legumes but I don't know of a sustainable solution for PK leaving the farm with crop outputs.
P and K are abundant in the world's agricultural soils. They just need to be 'eaten' (dissolved) by soil microorganisms.[1]
The problem is that farmers have been taught to ignore the health of soil organisms and just apply
a short-term bandaid chemical (vs biological) spray product, which causes more harm in the long-term. Take a wild guess who taught them that?
Probably companies like Bayer and Yara. I'm aware that chemicals like glyphosate are detrimental to fungi and soil bacteria.
But I don't think regenerative farming with no mineral inputs is sustainable either. As this story shows there isn't always enough PK to pull out of the soil https://www.newsroom.co.nz/green-dream-pushes-farmers-into-r...
>Despite the technical feasibility of the electrically-driven Haber–Bosch ammonia, the question still remains whether such revolution will take place. We reveal that its success relies on two factors: increased energy efficiency and the development of small-scale, distributed and agile processes that can align to the geographically isolated and intermittent renewable energy sources.
I have to say this article was published in December 2019, and since then some projects for new green ammonia plants have been planned (although I must update this information).
Synthetic fertilizers are not just about ammonia: urea is needed too, and the existing infrastructure accounts for both, produced in close proximity. And using natural gas, the big problem.
Also, another thing: urea production needs carbon, currently provided by methane. If the source is the atmosphere, then producing green fertilizer would not only be carbon neutral, it could become negative. But again, if, if, if...
Where renewable energy is cheap and not easily exportable (e.g. Greenland, that recycles energy-intensive aluminum), this could be a way of exporting it indirectly and of diversifying the economy. Either that or hydrogen exports.
There is also the geopolitical perspective, since the world trade of fertilizers depend too much on states that tend to regard international law as optional: Russia, Belarus and Morocco (for urea and potassium, potassium, and phosphorus, respectively).
> states that tend to regard international law as optional
I know HN isn't supposed to be about politics, and not wishing to get into specifics and thus provoke an detailed argument, but many of us know of plenty of other "friendly" states that are happy to ignore international law whenever and wherever it suits them.
Readit News
As an avid gardener who who got solar panels recently, I've seriously considered looking deeper into this. When I spec'd out my system, I did some back of the napkin math on mining bitcoin with surplus pixies during the day, and it came something on the order of 10x more profitable than what my utility is willing to give me for those same pixies.
However, I don't really use bitcoin. I do however, have an ongoing need for nitrogen fertilizers. I've been digging about into what it would take to drive the Haber Bosch process at a home scale. A couple of 10's of kg of fixed nitrogen a month would be more valuable to me than what my utility is willing to pay, and I could put it right to work in the garden beds.
Cool. And which of those can I generate using excess electrical energy from my solar panels?
>I have never used a chemical fertilizer in my garden, and am striving towards a completely autonomous fertilization cycle
That is great. I don't have the time or interest in managing animals, and I manage my space for food production because it gives me a sense of control and independence over my food-supply. Over the last 3 years I've imported almost 5000kg of animal manures into my gardens. Its incredibly expensive, and even with that additional fertility, I need more. Its more important for me to have the independence and control over my food-supply than it is to hold to a particular relgiosity around where my N comes from. If I have animal manures, I'll use them. If I have chemical fertilizers, I'll use them. When I have pest issues, I try to use IPM. When that fails, I'll use a pesticide.
https://www.cbc.ca/radio/asithappens/as-it-happens-friday-ed...
From what I understand it is very energy inefficient, but scales down well.
[1] https://en.m.wikipedia.org/wiki/Birkeland%E2%80%93Eyde_proce...
And for any other nitrogen uses. Haber-Bosch was originally conceived as a process for making cheaper explosives.
Wikipedia: "Allies had access to large deposits of sodium nitrate in Chile (Chile saltpetre) controlled by British companies. Germany had no such resources, so the Haber process proved essential to the German war effort. Synthetic ammonia from the Haber process was used for the production of nitric acid, a precursor to the nitrates used in explosives."
The problem is that farmers have been taught to ignore the health of soil organisms and just apply a short-term bandaid chemical (vs biological) spray product, which causes more harm in the long-term. Take a wild guess who taught them that?
[1] https://youtu.be/x2H60ritjag
Deleted Comment
>Despite the technical feasibility of the electrically-driven Haber–Bosch ammonia, the question still remains whether such revolution will take place. We reveal that its success relies on two factors: increased energy efficiency and the development of small-scale, distributed and agile processes that can align to the geographically isolated and intermittent renewable energy sources.
I have to say this article was published in December 2019, and since then some projects for new green ammonia plants have been planned (although I must update this information).
Synthetic fertilizers are not just about ammonia: urea is needed too, and the existing infrastructure accounts for both, produced in close proximity. And using natural gas, the big problem.
Also, another thing: urea production needs carbon, currently provided by methane. If the source is the atmosphere, then producing green fertilizer would not only be carbon neutral, it could become negative. But again, if, if, if...
Where renewable energy is cheap and not easily exportable (e.g. Greenland, that recycles energy-intensive aluminum), this could be a way of exporting it indirectly and of diversifying the economy. Either that or hydrogen exports.
There is also the geopolitical perspective, since the world trade of fertilizers depend too much on states that tend to regard international law as optional: Russia, Belarus and Morocco (for urea and potassium, potassium, and phosphorus, respectively).
I know HN isn't supposed to be about politics, and not wishing to get into specifics and thus provoke an detailed argument, but many of us know of plenty of other "friendly" states that are happy to ignore international law whenever and wherever it suits them.
For those who haven't heard it, the BBC's "One Day In August" is really worthwhile: https://www.bbc.co.uk/programmes/b04nrqsk
https://www.bondalti.com/en/multimedia/news/bondalti-fosters...
Dead Comment