Perhaps not the most reliable source of information is from my series of Childhood of Famous Americans. Reportedly, as a juvenile, Alex Bell tried stroking his cat to create electricity. The scientific experiment ended quickly when the non-scientific feline objected.
Depending on how it’s implemented, osmotic power can be used to spin a wheel (old-fashioned dynamo), as a “salt” battery, or in a capacitance scheme. I think there are other twists as well.
That doesn’t provide electricity directly though, so it’s not an answer to the OP. You’d have to use it to heat something up and extract energy from that or shin on a photovoltaic cell.
Depends on what you mean by commercial scale - power-grid level or commercially practical? I worked for a little wire in the area of wireless sensor nodes powered by harvested energy. These would be put in locations where replacing batteries would be expensive or impractical. We were looking into strain gages and associated circuitry on bridges which would be powered by vibration (through the piezoelectric effect). We also had a startup approach us to help develop a wireless sensor node for forest/jungle monitoring which would be powered by a couple of probes implanted in a tree, one on the trunk and one in the roots - I think basically a living “potato battery”. DOn’t remember the details.
Crackpot physics requiring, among other things unobtaininum mirrors:“As all surfaces around the lasing medium are highly reflective surfaces or mirrors, the photons thus formed will be continually and indefinitely reflected from the inner surface, at or near the speed of light.”
And while these mirrors are perfectly reflective and will not let a single photon go to waste the next step in the process has all the particles created by “photon collisions” pass through the walls, presumably without ripping them to shreds over time, or it’s not really going to be a useful generator now is it.
Oooooh, no good. This generates 3-phase juice. 3-phase leaves a scalar fingerprint even when transformed into 2-phase that damages any electronics more sensitive than a toaster. This is useless for my purposes.
JK, cool stuff.
Got the joke though?
Seriously, man, that means you’re* in*!
You could also make use of beta radiation more directly. Build a spherical capacitor, with the radioactive material in the center. Charge it up (negative terminal on the outside) to a voltage corresponding to just under the decay energy. Bleed off charge at the same rate that the source replenishes it.
Everyone always thinks that, in a potato battery, the potato is the power source. It’s not. The power source is the two electrodes, made of two different metals. The electrodes eventually wear out, and the battery dies, just like with any other battery. You’re much better off just putting those same electrodes in a conventional battery, with an electrolyte engineered to work better than potato juice.
Oh, and don’t dismiss batteries and/or fuel cells as just storage devices. You could get the energy to make batteries from other chemical sources like fossil fuels, without a separate electrical step in between. And there are fuel cells which run on, for instance, methane or alcohol.
A friend of a friend online started a business a while back about sticking kites or balloons in the air to harness electricity from clouds. I don’t remember exactly how it was supposed to work. At first I thought it was bullshit, but he is a very talented engineer and was working with one of his college professors. I eventually learned he was basically trying to do what lightning does, only slower and more controlled. No idea where that idea is today though. That was a couple of years ago and I haven’t heard anything since.
But at least the basic idea makes sense. There are huge charge differences between land and sky that could in theory be used to power electrical devices directly without a synchronous generator. Devil’s in the details, however.
I used to fly a set of tandem kites (these are like mine, but are not mine) using these things to control them. On one particularly wet & windy day (I know, I was younger and even dumber) I felt a little pinching at my knuckles when I’d send the kites straight up in anticipation of some cool move or another. As it got darker I was able to see the pinching was actually electrical arcs coming off the handles. I failed to grasp the commercial applications and just put the kites away for the evening.
[Bolding mine]
You do away the electrical step in between, but you add many more steps in cleaning the fuel for the fuel cells. As the technology stands today, these added steps are one of the many things that makes the technology not commercially attractive.
Wasn’t exactly a potato battery they were proposing, just the concept of sticking two electrodes into a tree made me think of “potato battery” as a simplification. From what I remember, they were trying to harvest energy using some difference in the chemistry between the sap in the trunk and the sap in the roots - said difference being maintained by photosynthesis. Maybe a delta in pH? Not a chemist/biologist, just an engineer.
Bottom line was that some MIT PhD got startup funding based on his thesis…
Should change your handle from B-Rad to B-Franklin…
Oh, sure, I never said it was practical. But it’s certainly possible, and might perhaps become practical at some point in the future (certainly more practical than anything involving antimatter).
Sounds like an inventive way to kill trees. After all, the tree is maintaining that imbalance for a reason, which has to do with keeping alive and growing. Well, it might not outright kill the tree, but will certainly stunt its growth.
It really depends on how much energy they’re extracting relative to the size of the tree. I’ve got a wristwatch powered by my metabolism and it hasn’t killed me yet.
OK, so how does that work?
Automatic watches are mechanical watches with an off balance weight and a ratchet type mechanism to wind up the spring using just normal arm movement.
Yeah, I know about those, but that’s not something I would describe as “powered by my metabolism”.