Hacker News Reader

Comment by ta988 | Hacker News Reader

I feel like it is missing most of the important questions. What's the impact on sea life (one sentence saying we need monitoring...) The techniques used mean that all the microorganisms, planktons, algaes will be destroyed by those processes. What is the yield of those approaches, you remove 1000 tons, but how much do you produce to make the devices, maintain and run them, the boats... What do you do with the CO2, that's now weight you have to move as well and put in containers that required CO2 to be made. This all should count in the equations for the credits, and from what we have seen in the past it is unlikely it will.

View on HN

> how much do you produce to make the devices, maintain and run them, the boats

Boats consume way more fuel than a layman may think. I’ve been on a ~80m / 20people crew coast guard ship for 6 weeks and did a napkin math onboard based on tank levels and refueling date. It was +1000l/person/day of diesel (can’t remember precise numbers). We were moving ~50% or the time. In addition of the motors there were many BIG generators to make everything work: heating, sewage, hot water, AC, pumps, motors for cranes, anchor raising… you also need your motors running at least in low speed even when still to control your position and direction.

I’m sure boats acting like platforms and with less crew to accommodate does consume less, however it’s still nothing comparable to an onshore plant.

It work "economically" because you often manage to refuel in an port with low fuel price.

I have wondered if you could tow a barge with the processing, then incentivize the box transports to pull the barge along behind. There are challenges with seas and storms and things like the tow line breaking.

I read a proposal for an air extraction system that fit in a container, so that you could stack a few on a container ship and they would process air as they went from port to port. Typically power challenged though (you want some clean energy powering them). Nuclear powered container ships would be good for this.

Hamilton class?

Won’t say more on the boat, I hope you understand, sorry…

My apologies, understood.

Also, ‘economically’ in this context is so far outside of what a normal person can process that it’s absurd. $500k/day-$3mln/day?

Timewizard post is dead so I respond here. Disclaimer I should have put above: It was my first and only time I worked on a big ship. My position was deckhand but had the chance to learn a lot from others crew members.

> This is not remotely representative of "boats."

I talked about the consumption with the first mate and he wasn’t surprised. He’s a long time sailor. I’m sure there is a variety of boat types but I don’t think we were representative of those that consume the most.

> Were you on a ice cutter or a research ship?

It wasn’t an ice cutter. We were sailing mostly around The Channel (France/UK) so "average" air temperature (~ 5-15 celcius)

> This is why they made anchors and why sailboats can function even without power

If the seabed is too deep you can’t. Also dropping or pulling a big anchor isn’t trivial: you need to find the right spot (wind, currents, coast rocks, seabed material…), do some calculation for chain length, some deckhands to operate it, time to drop it slow enough and not destroy your boat (see anchor fails on YouTube) and sometimes a few trials to "anchor" the anchor (it can drift of above parameter we’re not optimal). Also there’s always a chance to break the chain during the process. I’m sure all of this is easier or even trivial for smaller boats or in easy condition like an archipel with not much wind, waves or current.

Sailboats are great but another level of navigation techniques.

Also, you don’t completely shut down the engines even if drift isn’t a problem : startup isn’t trivial either.

Yeah this is seems like it's reduced the complexity down to one dimension (removing the CO2) and has blown past any of that, didn't even think about the algae initially, just energy expenditures getting this up and running, but yeah, that's pretty much saying you'll solve climate change by chopping down trees and planting golf course grass

They’re not even removing that much CO2 either

> Captura’s Port of Los Angeles pilot can remove about 100 tonnes of CO2 per year from seawater. The company’s new plant under construction in Hawaii will capture 10 times that amount—a measurement the company can definitively quantify.

So 1,000 tonnes of CO2 / year?

So back of the sticky note math, 1,000 ton/yr, at $7.37/ton carbon credit resell value per Google "AI" header thing, that's $7,370/year profit. Hopefully that covers the boat, employee salaries, and fuel. Good job team.

My god, exactly. But I think you mean $7,370/year revenue.

Meh, words. /s

To help quantify this further, a typical passenger car emits ~5 tonnes of CO2 per year. So we’re talking about offsetting 20-200 cars per year.

https://www.epa.gov/greenvehicles/greenhouse-gas-emissions-t...

Only if you ignore the who knows how many tons of CO2 was put into the atmosphere to create the thing. In reality that thing probably need to run several years to break even.

Oh no, the algae, nobody thought of them!

We like them for breathing purposes. They produce about 70% of the oxygen.

And an important food source for the fish we like to eat.

Yeah, this is a common reason that environmentalists oppose nuclear power. First you have to prove that what you're going to do is making an improvement. The key element to remember is that we got everything right until the 1970s. After that, it's best to not touch things.

Reply on news.ycombinator.com