4 ms·

OK, I'll bite: How much energy can they harvest? While realising that this is still highly experimental, early days and bleeding edge (and also very exciting!)

OK, I'll bite: How much energy can they harvest? While realising that this is still highly experimental, early days and bleeding edge (and also very exciting!) it would be very interesting to get some idea of the actual energy harvest, even though this will surely be an area of intense future research. I did not see any mention of it in the article, though, and the original paper seems to be paywalled.

jaclaz 3y ago
There was a thread from another article on the washington post: https://news.ycombinator.com/item?id=36091615 https://news.ycombinator.com/item?id=36091615 It is essentially the usual "breakthrough" that won't likey have any practical use for many years, the experimental device is tiny and produces very little power. It seems you need one billion of these devices to get 1 kW. >The device, the size of a fingernail and thinner than a single hair, is dotted with tiny holes known as nanopores. The holes have a diameter smaller than 100 nanometers, or less than a thousandth of the width of a strand of human hair. >While one prototype only produces a small amount of energy — almost enough to power a dot of light on a big screen — because of its size, Yao said Air-gens can be stacked on top of each other, potentially with spaces of air in between. Storing the electricity is a separate issue, he added. >Yao estimated that roughly 1 billion Air-gens, stacked to be roughly the size of a refrigerator, could produce a kilowatt and partly power a home in ideal conditions. The team hopes to lower both the number of devices needed and the space they take up by making the tool more efficient. Doing that could be a challenge.
- giarc 3y ago
  Some googling and napkin math. 1 fridge = 1 kW A fridge is 25 cubic feet, so 40 watts per cubic foot. A Dell E2422H monitor uses 13 watts while powered on. So a box 0.325 cubic feet could power a monitor, or a cube of 8.25" edge length. Assuming it was 100% efficient and endless supply of humid air etc.
  - importantbrian 3y ago
    > and endless supply of humid air etc. Floridians are getting really excited right now.
  - mojomark 3y ago
    I had a 5kW gas powered generator that more than lowered out 3 bedroom 1.5 bath house for when our power would go out - sometimes for several days (1 refrigerator, HVAC unit, microwave, electric washer/dryer, two laptops, 2 large screen TV's, hot water heater - all drawing power intermittently of course, but we never exceeded). It was about the size of a small riding lawn mower. If I could have 5 refrigerator-sized boxes in my backyard powering my house, I would be in.
    - jaclaz 3y ago
      >If I could have 5 refrigerator-sized boxes in my backyard powering my house, I would be in. Yep, but that would be 5 billion "cells". How much would a "nail sized" cell cost? If 0.001 $ (1/1000 of a dollar), that would be a nice, round 5 million dollar.
      - giarc 3y ago
        Sure, but the first LCD tv's were $50,000, now you can get one for $100. It won't be $5m forever.
        jaclaz 3y ago
        Yep, but prototypes of (small, monochrome) LCD screens were created in the '60's, your $50,000 data point would have been probably mid-1980's, and the $100 lcd tv's probably happened in the late 2010's. I wouldn't be surprised (if this humidity device actually works and can be bettered) that working regrigerator sized units will be availably in 2040 and be actually affordable by the 2070's.
      - notjulianjaynes 3y ago
        Unless I misunderstood, the fingernail sized object was just a prototype and the important thing isn't the size of the "cell" but the number of 100nm holes in the material. I wonder if the kind of lithography used for semiconductor manufactur would be a useful way to produce this material?
- schainks 3y ago
  huh, seems like you could realistically power a low end watch, though.
dafelst 3y ago
It is in the article: Finally, because air humidity diffuses in three-dimensional space and the thickness of the Air-gen device is only a fraction of the width of a human hair, many thousands of them can be stacked on top of each other, efficiently scaling up the amount of energy without increasing the footprint of the device. Such an Air-gen device would be capable of delivering kilowatt-level power for general electrical utility usage.
- ilyt 3y ago
  That seems like something that would be insanely easy to clog up by just dust in the air
  - fbdab103 3y ago
    Maybe it could be pre-filtered air in a closed loop? However, this already seems like magic to me, so I am unsure if it is possible to filter/recycle the air and still come out net energy positive. Alternatively, maybe there could be some kind of washing step where the plates are washed/air forced through/voltage applied to remove debris.
  - pengaru 3y ago
    Indeed, but at utility-scale you also likely have some energy to spare for powering an electrostatic dust filter at the intakes... My parents' house had a Honeywell brand electrostatic air filter in front of the air handler that wasn't cost-prohibitive to operate, and didn't have a drip pan or anything so I don't think it stripped moisture either. We'd just toss the large metal filter cartridges in the dish-washer periodically, which barely fit. They didn't pose a significant air restriction, unlike conventional pleated physical filters.
    - hollerith 3y ago
      Have they figured out how to prevent this tech from producing ozone?
      - 3y ago
AtlasBarfed 3y ago
It would seem to me that surface area is the key. Fractals or similar techniques? It says the material isn't important, so maybe some sort of crystal growth could do it? a kilowatt for a fridge is pretty good honestly, and it stacks vertically. Or you integrate it with the underside of solar panels for better yield. 1KW/"fridge" is a lot more than I was expecting.

jaclaz 3y ago

There was a thread from another article on the washington post: https://news.ycombinator.com/item?id=36091615 https://news.ycombinator.com/item?id=36091615 It is essentially the usual "breakthrough" that won't likey have any practical use for many years, the experimental device is tiny and produces very little power. It seems you need one billion of these devices to get 1 kW. >The device, the size of a fingernail and thinner than a single hair, is dotted with tiny holes known as nanopores. The holes have a diameter smaller than 100 nanometers, or less than a thousandth of the width of a strand of human hair. >While one prototype only produces a small amount of energy — almost enough to power a dot of light on a big screen — because of its size, Yao said Air-gens can be stacked on top of each other, potentially with spaces of air in between. Storing the electricity is a separate issue, he added. >Yao estimated that roughly 1 billion Air-gens, stacked to be roughly the size of a refrigerator, could produce a kilowatt and partly power a home in ideal conditions. The team hopes to lower both the number of devices needed and the space they take up by making the tool more efficient. Doing that could be a challenge.

giarc 3y ago
Some googling and napkin math. 1 fridge = 1 kW A fridge is 25 cubic feet, so 40 watts per cubic foot. A Dell E2422H monitor uses 13 watts while powered on. So a box 0.325 cubic feet could power a monitor, or a cube of 8.25" edge length. Assuming it was 100% efficient and endless supply of humid air etc.
- importantbrian 3y ago
  > and endless supply of humid air etc. Floridians are getting really excited right now.
- mojomark 3y ago
  I had a 5kW gas powered generator that more than lowered out 3 bedroom 1.5 bath house for when our power would go out - sometimes for several days (1 refrigerator, HVAC unit, microwave, electric washer/dryer, two laptops, 2 large screen TV's, hot water heater - all drawing power intermittently of course, but we never exceeded). It was about the size of a small riding lawn mower. If I could have 5 refrigerator-sized boxes in my backyard powering my house, I would be in.
  - jaclaz 3y ago
    >If I could have 5 refrigerator-sized boxes in my backyard powering my house, I would be in. Yep, but that would be 5 billion "cells". How much would a "nail sized" cell cost? If 0.001 $ (1/1000 of a dollar), that would be a nice, round 5 million dollar.
    - giarc 3y ago
      Sure, but the first LCD tv's were $50,000, now you can get one for $100. It won't be $5m forever.
      - jaclaz 3y ago
        Yep, but prototypes of (small, monochrome) LCD screens were created in the '60's, your $50,000 data point would have been probably mid-1980's, and the $100 lcd tv's probably happened in the late 2010's. I wouldn't be surprised (if this humidity device actually works and can be bettered) that working regrigerator sized units will be availably in 2040 and be actually affordable by the 2070's.
    - notjulianjaynes 3y ago
      Unless I misunderstood, the fingernail sized object was just a prototype and the important thing isn't the size of the "cell" but the number of 100nm holes in the material. I wonder if the kind of lithography used for semiconductor manufactur would be a useful way to produce this material?
schainks 3y ago
huh, seems like you could realistically power a low end watch, though.

dafelst 3y ago

It is in the article: Finally, because air humidity diffuses in three-dimensional space and the thickness of the Air-gen device is only a fraction of the width of a human hair, many thousands of them can be stacked on top of each other, efficiently scaling up the amount of energy without increasing the footprint of the device. Such an Air-gen device would be capable of delivering kilowatt-level power for general electrical utility usage.

ilyt 3y ago
That seems like something that would be insanely easy to clog up by just dust in the air
- fbdab103 3y ago
  Maybe it could be pre-filtered air in a closed loop? However, this already seems like magic to me, so I am unsure if it is possible to filter/recycle the air and still come out net energy positive. Alternatively, maybe there could be some kind of washing step where the plates are washed/air forced through/voltage applied to remove debris.
- pengaru 3y ago
  Indeed, but at utility-scale you also likely have some energy to spare for powering an electrostatic dust filter at the intakes... My parents' house had a Honeywell brand electrostatic air filter in front of the air handler that wasn't cost-prohibitive to operate, and didn't have a drip pan or anything so I don't think it stripped moisture either. We'd just toss the large metal filter cartridges in the dish-washer periodically, which barely fit. They didn't pose a significant air restriction, unlike conventional pleated physical filters.
  - hollerith 3y ago
    Have they figured out how to prevent this tech from producing ozone?
    - 3y ago

AtlasBarfed 3y ago

It would seem to me that surface area is the key. Fractals or similar techniques? It says the material isn't important, so maybe some sort of crystal growth could do it? a kilowatt for a fridge is pretty good honestly, and it stacks vertically. Or you integrate it with the underside of solar panels for better yield. 1KW/"fridge" is a lot more than I was expecting.