03/17/2024
ELECTRICITY FROM DIPPING BIRDS
There's a toy called the dipping bird, you can buy it on Amazon and you've probably seen it. Google amazon dipping bird toy. It's powered by evaporation of water.
Recently a paper came out about harvesting electricity from that toy, a new source of renewable electricity.
Here is a video made by the authors of that recent drinking bird paper:
https://www.youtube.com/watch?v=caMuQbPwKYM&ab_channel=ScienceX%3APhys.org%2CMedicalXpress%2CTechXplore
and a boring 8 minute podcast about the physics.
https://www.youtube.com/watch?v=QYbHKzK-uEg&ab_channel=RobertMurray-Smith
And another 2 year old video showing a dipping bird making electricity:
https://www.youtube.com/watch?v=HOAXSBg8Kp4&ab_channel=anisotropicplus
The recent bird paper reports 100 Volts. But they don’t report the amount of charge that is stored at that 100 Volts. That would give the energy stored. But I can’t find the energy per dip, nor the average power on the internet., which I wild-guessed is on the order of a milliwatt.
So, here’s my real estimate:
At each dip, I guess that about an ounce of blue fluid (say m = 25 grams = 0.025 kg) falls about 4 inches (say, h=10 cm = 0.1 m) and there is one dip every t = 20 seconds. And, say, the
conversion of work to electricity is about 10% efficient (that’s e = 0.1). Using g = 10 N/kg, So, that gives
Power = P = e * m * g * h / t = 0.1 * 0.025 * 10 * 0.1 / 20 watts = 0.0000125watts = 1 / 8000 watts. =1/8 milliwatt.
That’s about 1/8 of my wild guess of a milliwatt.
That means that 800,000 birds could generate 100 watts, which would make, at 10 cents per KWH, 1 cent of electricity per hour and could power one small weak blender.
At $10 per bird on amazon, plus the cost of electronics and power generation, that would be $8,000,000 (plus) to make a dipping bird evaporation generator to power a blender. I don’t think you are going to see a video of that in this, or any other, lifetime.
Somebody else did the calculation. Back in 2009, somebody estimated that 4 * 10^16 birds could power the United States:
https://macniven.blogspot.com/2009/11/drinking-birds-solve-energy-crisis.html
Now, the internet says that the USA uses about 42* 10^12 kwh per year. Given that there are about 10,000 hours in a year, and 1000 watts in a kilowatt, that’s an average power of about 4 * 10^12 watts. Those 2009 people estimated that 4 * 10^16 birds could do that, so their estimate for the power you could generate from one bird is about
P = 4*10^12 /( 4*10^16) = 0.0001 watts per bird.
A tenth of a milliwatt.
That is, their estimate, back in 2009, is basically the same as mine (1/8 of a milliwatt).
Thinking about investing in birds for electricity, $8Million of birds can make you $100/year. So the payback on investment would be about 80,000 years. Not as good as rooftop solar.
I am sure that most of us have seen one of those cute drinking birds like the one pictured here. You fill a cup with water and get their foa...
