My gut was that this was some sort of April 1 paper that released early, especially when the link to the paper from CNN was broken. Now that we found an actual paper, I'm still not convinced this wasn't done tongue-in-cheek.
Probably costs for a drinking bird machine are cubic function to size, while power generation is square or linear.
Funny to think about CNNs vision here, every coastline and backyard swimming pool dotted with drinking bird machines. Need to charge your phone at the restaurant? Pull out your pocket drinking bird and put it on top of your water glass.
Like first of all, we can already generate electricity from evaporation. They're called steam turbines and they're very old technology.
These work at STP, but so do steam turbines if you use a mirror dish to concentrate sunlight.
Secondly, this is just solar power. It's just photon -> heat -> movement -> electricity instead of directly photon -> electricity. My naive take is that it will never be as efficient as solar due to the inherent losses in converting energy.
Lastly, even if we did want to something like this, these birds seem like the worst way to do it.
Couldn't we tap into the same energy source by putting something lightweight and porous like aerogel or cheesecloth onto an "elevator" of sorts and moving it up into the clouds and back down? I.e. it starts off dry at ground level, weighing 10g or whatever. We hoist it up to the clouds where it soaks up water until it weighs 2kg or whatever, then we lower it and harvest the potential energy. Then we wait for the sun to dry it out and we do it again.
It weighs 10g on the way up and something much more on the way down, which I think should net us energy.
To be clear, I still think actual solar power makes more sense, but I don't think grid-scale deployment of this would involve literal drinking birds.
Evaporation engines like the drinking bird operate on the other half of the water cycle (surface water -> vapor -> cloud water). A 'cloud sponge elevator' would operate on essentially the same half of the water cycle that we already tap into with hydroelectric dams (cloud water -> rain -> surface water). We could get the same increase in energy per unit water by building dams almost as high as the clouds. Now, that would be a huge capital expense (but probably look pretty awesome), but I'm not sure it would be more of a capital expense per watt than a cloud sponge elevator.
One of the reasons why people are interested in evaporation engines is to try to tap into the energy in the water cycle, like dams do, without the high capital expense. Of course, dipping birds aren't efficient, but they also aren't the only possible design.
> m not sure it would be more of a capital expense per watt than a cloud sponge elevator.
If I were going to take a wild guess, the dam is probably cheaper lol.
> One of the reasons why people are interested in evaporation engines is to try to tap into the energy in the water cycle, like dams do, without the high capital expense. Of course, dipping birds aren't efficient, but they also aren't the only possible design.
You seem like you know more than me here, what's the theory behind capital costs being lower? Is it the lack of need to contain pressure?
Probably costs for a drinking bird machine are cubic function to size, while power generation is square or linear.
Funny to think about CNNs vision here, every coastline and backyard swimming pool dotted with drinking bird machines. Need to charge your phone at the restaurant? Pull out your pocket drinking bird and put it on top of your water glass.