Ask HN: What problems don't have a profitable business solution? • Hacker News Board

Re: Ask HN: What problems don't have a profitable business solution?

#41

Post by danieltillett » Wed, Dec 13, 2017, 10:55 PM UTC

eesmith wrote: post #39

danieltillett wrote: post #35

Earlier quoted context omitted.

I think where you might be going astray is confusing the biomass of the fish with the carbon fixed. The fish sit at the top of the food chain and account for a tiny percentage of the carbon captured - they are just the profit center. Most of the carbon is fixed by phytoplankton and the next stage in the food chain. As these die the carbon in the water column increases and eventually the excess carbon settles below 20…

Thank you. Yes, that was what I was missing. "400 tons of carbon for every ton of phosphate added" ... how long does that take? It's diffusion limited, yes? Ahh, I followed the Wikipedia link to https://www.atmos-chem-phys.net/9/5539/2009/acp-9-5539-2009.... . > Ocean fertilisation options are only worthwhile if sustained on a millennial timescale and phosphorus addition may have greater long-term potential than iron…

You actually have to provide homes for the fish (floating structures) that act like a surface wreck. The fish then hang around the floating material and and breed and grow.

The response to phosphate addition is surprisingly fast - depending the fish you wanted to harvest you are looking at a couple of years at most before you had a harvestable amount of fish to sell.

The law in this area is uncertain. Under the various international treaties it is not legal to dump garbage in the oceans, but no one is exactly sure where phosphate fertilisation sits. Even if turns out to be illegal all you need to do is find a friendly pacific island nation and do all the phosphate dumping in their waters and let the ocean currents do the work for you :)

The nice thing about this idea is that it turns what appears to be an impossible dream and makes it possible to make a profit solving it.

Re: Ask HN: What problems don't have a profitable business solution?

#42

Post by eesmith » Wed, Dec 13, 2017, 11:01 PM UTC

danieltillett wrote: post #41

eesmith wrote: post #39

Earlier quoted context omitted.

Thank you. Yes, that was what I was missing. "400 tons of carbon for every ton of phosphate added" ... how long does that take? It's diffusion limited, yes? Ahh, I followed the Wikipedia link to https://www.atmos-chem-phys.net/9/5539/2009/acp-9-5539-2009.... . > Ocean fertilisation options are only worthwhile if sustained on a millennial timescale and phosphorus addition may have greater long-term potential than iron…

You actually have to provide homes for the fish (floating structures) that act like a surface wreck. The fish then hang around the floating material and and breed and grow. The response to phosphate addition is surprisingly fast - depending the fish you wanted to harvest you are looking at a couple of years at most before you had a harvestable amount of fish to sell. The law in this area is uncertain. Under the vario…

Thank you for your patience with me. Your comments were quite informative. I'm now well beyond the point where I can make even somewhat relevant questions, much less comments. :)

EDIT: Oh, wait, I do have one more question. In order for this to be an effective form of carbon reduction, how much will the fish population increase? As the supply goes up, the prices will go down, and I'm still not convinced that the amount of carbon capture needed is economically justified by the increase in fish supply.

Re: Ask HN: What problems don't have a profitable business solution?

#43

Post by danieltillett » Thu, Dec 14, 2017, 2:54 AM UTC

eesmith wrote: post #42

danieltillett wrote: post #41

Earlier quoted context omitted.

You actually have to provide homes for the fish (floating structures) that act like a surface wreck. The fish then hang around the floating material and and breed and grow. The response to phosphate addition is surprisingly fast - depending the fish you wanted to harvest you are looking at a couple of years at most before you had a harvestable amount of fish to sell. The law in this area is uncertain. Under the vario…

Thank you for your patience with me. Your comments were quite informative. I'm now well beyond the point where I can make even somewhat relevant questions, much less comments. :) EDIT: Oh, wait, I do have one more question. In order for this to be an effective form of carbon reduction, how much will the fish population increase? As the supply goes up, the prices will go down, and I'm still not convinced that the amou…

This is a rather hard question to answer as it would depend on how elastic demand is for fish and how efficiently the phosphate is converted to fish.

You could choose to run the whole operation semi-inefficiently where you chose to only catch and sell a portion of the fish, or use the fish as feed for other higher value fish like salmon and bluefin tuna.

My minor contribution to the idea was to workout that you don’t need purified phosphate to fertilise the oceans. We could just use phosphate rich rock to make a slow release pumice-like fertiliser that floats on the surface (using a photo-degradable polymer). This gets the phosphate cost down from around US$1600/t to something under $50/t. I wrote a paper on this many years ago, but I never got around to publishing it. I might try and turn it into a blog post if I get a chance.