denkenberger

Dr. David Denkenberger co-founded and is a director at the Alliance to Feed the Earth in Disasters (ALLFED.info) and donates half his income to it. He received his B.S. from Penn State in Engineering Science, his masters from Princeton in Mechanical and Aerospace Engineering, and his Ph.D. from the University of Colorado at Boulder in the Building Systems Program. His dissertation was on an expanded microchannel heat exchanger, which he patented. He is an associate professor at the University of Canterbury in mechanical engineering. He received the National Merit Scholarship, the Barry Goldwater Scholarship, the National Science Foundation Graduate Research Fellowship, is a Penn State distinguished alumnus, and is a registered professional engineer. He has authored or co-authored 134 publications (>4400 citations, >50,000 downloads, h-index = 34, second most prolific author in the existential/global catastrophic risk field), including the book Feeding Everyone no Matter What: Managing Food Security after Global Catastrophe. His food work has been featured in over 25 countries, over 300 articles, including Science, Vox, Business Insider, Wikipedia, Deutchlandfunk (German Public Radio online), Discovery Channel Online News, Gizmodo, Phys.org, and Science Daily. He has given interviews on 80,000 Hours podcast (here and here) and Estonian Public Radio, WGBH Radio, Boston, and WCAI Radio on Cape Cod, USA. He has given over 80 external presentations, including ones on food at Harvard University, MIT, Princeton University, University of Cambridge, University of Oxford, Cornell University, University of California Los Angeles, Lawrence Berkeley National Lab, Sandia National Labs, Los Alamos National Lab, Imperial College, and University College London.

Wiki Contributions

Comments

Sorted by

Then recently we have the example where an 11-year-old (!) walked less than a mile into a 370-person town, and the mother was charged with reckless conduct and forced to sign a ‘safety plan’ on pain of jail time pledging to track him at all times via an app on his phone.

Though there was some pushback that the mother did not know where the kid was, this still seems confusing given rules around school commutes. Many schools do not provide bus service within half a mile up the school, expecting kids to walk or bicycle. In Alaska, it was 1.5 miles even though it got down to -40°! And there generally does not appear to be an age limit where parents are required to go with their kids, so it sounds like it's okay for a 5-year-old to do this.

For something in the range of $10M/y we think you can operate a system capable of detecting a novel pathogen before 1:1000 people have been infected.

Sounds promising! I assume this is for one location, so have you done any modeling or estimations of what the global prevalence would be at that point? If you get lucky, it could be very low. But it also could be a lot higher if you get unlucky.
Have you done any cost-effectiveness analyses? Do you think that many people would be willing to take actions to reduce transmission etc in a case where no one has gotten sick yet?

Ground shipping is both a complement and a substitute for water shipping, so the net effect isn’t obvious. (Or at least, it’s not obvious to me).

Since overall freight moved wouldn't change that much (see my comment in this thread), the main economic efficiency of repeal is obtained by using ships instead of ground transport, because ships are cheaper. So overall, ships must be a substitute for ground transport. However, it's possible that some routes would be nearly all rail right now, and if it switched to primarily ships, there may be some additional trucking involved because it's not worth putting on a train for a relatively short distance. Have you looked at any studies examining effects on different modes (I haven't)? If repealing the Jones Act actually did increase trucking, then it could be positive for overall employment as the labour intensity of trucking is so much higher than the other modes.

Also, if a certain interest group has not lobbied in a policy area in the past (as I think is the case here?), then that's nonzero evidence that they will continue to not lobby in that policy area in the future.

It does look like ground transport has not lobbied, which is surprising to me, but I agree it does provide evidence that they will continue to not lobby.

Since I couldn't find it quickly on the web, GPT o1 estimated that the labour hours per ton kilometer of trucking is about 100 times as much as ships, and rail is just about the same as ships (I would have thought rail would have been at least a few times higher than ships). So based on the historic US and current Europe, maybe water transport in the US would increase an order of magnitude if the Jones act were repealed. As Zvi points out, even though the US ship manufacturing jobs would be lost, there probably would be an increase overall shipping employment because of repairing ships and staffing ships. So let's say staffing the ships is 3 times as much as the current employment of manufacturing and staffing very few ships. I suspect that most of the lost inland transportation due to the shift from shipping would be rail, but even if 10% of it were trucking, that would mean the loss of jobs in trucking would be 10 times as much as the staffing of the additional ships, and 30 times as much as the employment constructing and staffing the current ships.[1] So if you had to compensate 30 times as many people, it would be much more difficult. Now it is true that the majority of total cost of rail and shipping is energy (it's about even between energy and labour for trucking), so the large overall economic savings of moving to shipping should be sufficient to compensate all those truckers, but it's just not nearly the slamdunk that it appeared to be when only looking at marine employment.

  1. ^

    Technically not all the freight that would be moved by ships is currently moved by truck/rail/pipeline because a smaller amount gets transported because of the higher cost. But using Zvi's example of $0.63 per barrel increase, since it is 42 gallons per barrel, that's 1.5 cents/gallon, or ~0.5% of the total cost, which wouldn't change quantity demanded very much, well within other uncertainties of this analysis.

The thing is, there really are not all that many of them. Even if you counted every job at every shipyard, and every job aboard every Jones Act ship, and assumed all of them would be completely lost, it simply is not that many union workers.

 

But the Jones Act is massively benefiting truck and rail staff (and to some extent, pipelines), so I think there are a lot more workers you would need to compensate. Also, I would expect the truck and rail lobbies to try to save the Jones Act.

It would be helpful to see a calculation with your rates, the installed cost of batteries, cost of the space taken up, losses in the batteries and convertor, any cost of maintenance, lifetime of batteries, and cost (or benefit) of disposal.

If you have 3 days worth of storage, even if you completely discharge it in 3 days and completely charge it in the next 3 days, you would only go through about 60 cycles per year. In reality, you might get 10 full cycles per year. With interest rates and per year depreciation, typically you would only look out around 10 years, so you might get ~100 discounted full cycles. That's why it makes more sense to calculate it based on capital cost as I have done above. If you're interested in digging deeper, you can get free off grid modeling software, such as the original version of HOMER (new versions you have to pay).

Even now at $1000/kW-hr retail it's almost cost-effective here to buy batteries to time-shift energy from solar generation to time of consumption. At $700/kW-hr it would definitely be cost-effective to do daily load-shifting with the grid as a backup only for heavily cloudy days.

Please write out the calculation. 

Have there been some recent advances in compressed air energy storage? The information I read 2-3 years ago did not look promising at any scale.

Aboveground compressed air energy storage (tanks) is a little cheaper than chemical batteries. But belowground large compressed air energy storage is much cheaper for days of storage, with estimates around $1 to $10 per kilowatt hour. Current large installations are in particularly favorable geology, but we already store huge amounts of natural gas seasonally in saline aquifers. So we can basically do the same thing with compressed air, though the cycling needs to be more frequent.

That does sound like an excessive markup. But my point is even with the wholesale price, chemical batteries are nowhere near cost-effective for medium-term (days) electrical storage. Instead we should be doing pumped hydropower, compressed air energy storage, or building thermal energy storage (and eventually some utilization of vehicle battery storage because the battery is already paid for for the transport function). I talk about this more in my second 80k podcast.

Yes, but the rest of my comment focused on why I don't think defection from just the electric grid is close to economical with the same reliability.

But with what reliability? If you don't mind going without power (or dramatically curtailed power) a few weeks a year, then you could dramatically reduce the battery size, but most people in high income countries don't want to make that trade-off.

Load More