avernon
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2 years ago
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on: CATL has announced a new “condensed” battery with 500 Wh/kg
Hub and spoke is primarily used to fill large planes. If you have 10-20 passenger electric planes you'd land at some random county airport, eat a hamburger or a taco while the plane recharges, then get back on the same plane and finish the trip. So you'd have a layover like hub and spoke but all the concerns about missing connections go away.
avernon
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3 years ago
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on: Metal Without Mining
Yes, I read the underlying paper a while back. It only looks at the very first step of a Dow-like process, before any electrochemistry happens. Instead of dumping hydroxide in a tank, they expose it to hydroxide in a serpentine flow path. When I was reading into this before calcium didn't seem to be too big of a problem for the Dow process because the calcium compounds are more soluble than magnesium hydroxide. They were actually adding more calcium with the lime. So their comparison may be to a different method than the Dow Process. It didn't seem particularly useful.
Then you neutralize the magnesium hydroxide with hydrochloric acid to make Magnesium chloride and do molten salt electrolysis on it to make pure magnesium and chlorine.
avernon
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3 years ago
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on: Metal Without Mining
They mention that they are doing electrochemistry. A huge portion of historical magnesium production is from electrolysis, including the only operating plant in the US. Past methods have used lime to precipitate magnesium (Dow) or evaporation ponds to concentrate it (the current Utah plant). Probably the new thing they are doing is using something like Chlor-Alkali to make base that precipitates the magnesium instead of using lime. Then the electrolysis of molten magnesium salts would be similar to products of today. There is some chance they have improvements in these areas, but there are really only so many options. The job descriptions they've posted support this hypothesis.
Recently most magnesium comes from China. They mine ore, throw it in a coal-fired furnace along with some reducing agents, then collect pure magnesium vapor. This process is more labor and energy intensive, but has significantly less CAPEX. Works for China.
Chlor-alkali is more expensive than lime and the back-end electrolysis is more expensive than thermal reduction. So I'd be skeptical they are going to lower costs without some kind of CAPEX reducing magic for molten salt electrolysis.
avernon
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3 years ago
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on: Westinghouse sees a tech disrupter in its eVinci microreactor
In this case it is boil sodium, condense sodium to heat air, run air through turbine.
avernon
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3 years ago
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on: Utilities Want to Convert Coal Plants to Nuclear; Skeptics Abound
Quaise wants to use old coal plants. So yes if you can drill down super deep to hot enough temperatures.
avernon
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4 years ago
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on: Launch HN: Charge Robotics (YC S21) - Robots that build solar farms
Will your system be robust to changes in solar farm design? Like if the industry goes towards the Erthos model of installing panels on the ground without racking or trackers?
avernon
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4 years ago
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on: Geothermal's path to relevance: cheap drilling
Germany has a 220 euro/kWh feed in tariff subsidy for geothermal.
avernon
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4 years ago
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on: Geothermal's path to relevance: cheap drilling
Drilling cost is usually estimated for drilling in sedimentary rock with assumptions about how casing is run ;)
It is possible that drilling 30,000' of granite has conditions that make the estimation model irrelevant. 5 km isn't really deep enough, anyway. My next post will cover the thermo. It is pretty dang hard to get down to anything approaching $50/MWh. Definitely need more than cheap drilling.
avernon
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4 years ago
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on: Tesla Q3 2021 Vehicle Production and Deliveries
Tesla was founded in 2003, Rivian in 2009. So Tesla took five years to start Roadster production, while Rivian has taken 12 years until first customer deliveries. Maybe Rivian will ramp faster. Sam Korus tracks the numbers and so far Tesla is ramping faster than Ford, making it the fastest ramping car manufacturer in American history. I wouldn't be surprised if some Chinese companies could go faster. It is much faster than what Toyota did. They are very methodical, which is why they have almost zero pure EV sales.
avernon
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4 years ago
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on: In older adults alcohol abstinence is associated with increased dementia risk
The data is observational, which generally means you should ignore it. It is too noisy.
There were those studies that showed moderate alcohol use improved health and only heavy drinkers saw detrimental health effects. The problem was that "no drinking" group included people that weren't drinking because of poor health. Later studies compared drinking vs. a "no drinking" sample of people that drank around two glasses of wine per year. The improved health effects completely disappeared. The more you drink, the worse it is for your health.
So this study is like that in using a potentially unhealthy comparison group. They try to offset that a little by also throwing in people that quit drinking. But it is likely that some people quit drinking because of health problems. So I'd guess that this study has the same problem with an unhealthy comparison group. The study probably can't tell you what the actual relationship between alcohol use and dementia with any authority.
avernon
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4 years ago
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on: GM tells some Bolt owners to park 50 feet away from other cars
The people I know with electric cars charge at home the vast majority of the time. Swapping adds a lot of complexity and cost in the pack design. NIO is doing swaps as another commenter pointed out, but more customers in China live in apartments. In the end, I think charging stations will be ubiquitous, even for apartment dwellers, and swaps will be rare.
avernon
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4 years ago
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on: GM tells some Bolt owners to park 50 feet away from other cars
The problem here is the form factor of the cell as much as the chemistry. Pouch style cells are very difficult to regulate temperature in. This is a key reason why other automakers like Tesla use the small cylinder cells. Chinese companies like BYD have always used lithium iron phosphate. It has less energy density than lithium nickel batteries like NCA and NMC, but is cheaper. The patent was never taken out in China and the key patent expires for the rest of the world in April 2022. As much as 3/4 of vehicle batteries might end up being LFP. Improvements in the chemistry and less need for cooling systems and packaging mean its disadvantages aren't so glaring. Plus there aren't enough nickel mines to supply the coming avalanche of demand. Lithium, iron, and phosphate are plentiful.
avernon
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4 years ago
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on: Rural America Is Gearing Up for a Generation of Change
This must be surprising to people, but the prairie co-evolved with ruminants like cows and buffalo. It literally dies and undergoes desertification without them. Buffalos can't breed fast enough to fill this niche for a long time. If we want healthy prairie we will have to have herds of cattle munching on the grass whether we choose to eat them or not.
avernon
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4 years ago
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on: Rural America Is Gearing Up for a Generation of Change
I think there are enough hackers that come from agricultural communities to give it a little boost. If I had discussed whether cows were evil or not, it looks like it might have gone to the front page!
It is hard to predict consumer taste, but I do think there will be some people that want beef on the hoof. And if you are utilizing holistic management type processes the biggest cost is the land. So the land price can flex down to make grass finished beef more competitive in a way that is harder for feedlots. And there is a lot of crop land, like in Western Kansas, that isn't really sustainable as crop land because they are lowering the water table pretty fast. So that will all go back to range land. Grazing land is already pretty cheap, 1000-1500/acre in most places. They can handle a haircut better than prime land in Iowa that is $5000-$10,000 acre. So more grazing land, more hobby farm and exurb like development. The worst off people are going to be large landowners with prime cropland. It could be a pretty big compression of the Gini coefficient where people that own less land can find other jobs from remote work or better transportation and end up better off even if their land value declines a lot. If your family owns a 10,000 acre corn and soybean farm, labor income can't replace the lost land value.
avernon
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4 years ago
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on: Launch HN: Buoyant (YC S21) – Blimp drones for air freight
Did you choose batteries for the first version to simplify the power train? Also, why use hydrogen instead of a cheaper, buoyant neutral fuel like propane? If you are worried about the carbon, you can always buy direct air capture credits.
avernon
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4 years ago
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on: Launch YC S21: Meet the Batch, Thread #8
Is the chain open source with permission-less validators?
avernon
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4 years ago
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on: So you want to build a house more efficiently
austinvernon.com was taken, I had the ENS name, and I was curious about IPFS, so I used it. The system works surprisingly well, mostly thanks to Cloudflare. I've only been using it for a month, though. And its a static site with zero JS or any analytics. I haven't tried to add it to google search console or anything.
avernon
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4 years ago
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on: So you want to build a house more efficiently
First you need to get a metamask wallet. Then you buy some ETH for the wallet. Finally go to ens.domains and register your name.
It is very friendly with IPFS, which is how I host my blog. So I put the IPNS permalink in my ENS name contract (managed on ens.domains). The .link is there because browsers can't resolve ENS names. Cloudflare runs a system that checks Ethereum for the browser and redirects to the correct IPFS name if you add the .link.
I wrote a post on how to set up a blog like this. It is way simpler to use something like Fleek, though.
edit to add link: https://austinvernon.eth.link/blog/ipfsbasics.html
avernon
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4 years ago
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on: So you want to build a house more efficiently
Thanks! If I would have known it would go to front page of Hacker News I would have had one of my construction science friends proof read it first!
I've been writing for fun and to learn and have always been curious about construction productivity.
avernon
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4 years ago
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on: Amazon’s newest euphemism for overworked employees is ‘industrial athlete’
You are 100% correct. This has been a common term in the manufacturing industry when focusing on ergonomics safety and reducing repetitive stress injuries for quite some time.
The connotation has generally been positive and was a created by the staff trying to improve safety and reduce injuries.