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How much power can we expect from rainfall?

eighteenthelephant.com

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Re: How much power can we expect from rainfall?

#91

Wrong. One can harvest power from raindrop. It's called an hydro-dam. Seems to be working pretty well from what I know.

Not sure why the snark is called for - FTA explicitly calls this out: “ (There is, by the way, a very good way to harness rain for renewable electricity: let geography concentrate the water into a river, then build a dam and a hydroelectric plant!)”

[deleted]

Re: How much power can we expect from rainfall?

#92
post #14

Earlier quoted context omitted.

It will never work! The collection structures will fail left and right, the surrounding soil will be saturated and cause mudslides, you'll have to evict a bunch of people and buy their land, and besides, what about the downstream farmers? They don't give a dam!

How will salmon get back up into the gutters to spawn?

Salmon tubes!

Re: How much power can we expect from rainfall?

#93

Earlier quoted context omitted.

>in real life, the alternative way of not letting air take much energy from the falling water is easier to build: make larger “droplets”, and have them tailgate each other really closely (also called a waterfall) To make this "aqua electricity" viable in the real world you would need huge bodies of water penned up and ready to be released at the appropriate time. Like the size of a lake. Pretty ridiculous.

That body of water also needs to be placed high enough for it to release a waterfall. I can’t think of something. Some large geological structures, perhaps? I dunno. Maybe Elon Musk has a wacky idea to inverse this problem and build tunnels below lakes to make this work.

Coquitlam Lake actually has a tunnel leading to Buntzen Lake for the purposes of supplying it with water for power generation. Pipes then carry the water down to a generating station on the ocean shore. https://curiocity.com/vancouver/wp-content/uploads/2019/08/p...

Re: How much power can we expect from rainfall?

#94
I didn't read the article, and I know it's more about math than an actual plan, but as a tangent I wanted to say that there's a cost to preventing rain from reaching the earth - even if we eventually returned the water there and didn't pollute or reduce the water. I think by altering this age-old cycle, we would lose some of the impact on the soil, and plants, the way it rolls downwards into increasing rivers.

We've caused a lot of damage with pavement and structures. The benefit of the power generated would have to be weighed against this cost.

Re: How much power can we expect from rainfall?

#95

Earlier quoted context omitted.

Yeah, the effectiveness of wide area water collection is why your suggestion is 'stupid'. That's ok. Where it's possibly not stupid is in the comment you linked to "...as energy is linear with height" Sure potential energy is linear with height, but energy conversion efficiency is I think non-linear. You can I think collect more than 10x useful energy from an object that is 10x as hot. Equally I suspect you can get m…

> Equally I suspect you can get more than 10x useful energy from a column of water 10 miles high than from a column of water 1 mile high. For a given flow rate, no. High pressure water can be fairly efficiently converted to electrical energy, which itself can fairly efficiently be converted between low voltage+high current to high voltage+low current. All the conversions are linear and well understood - there is no m…

OK, you sound like an expert (not sarcasm) so if I may (and please note I never suggested a squaring relationship),

> High pressure water can be fairly efficiently converted...

And lower pressure less efficiently converted? Therefore the higher the column, the higher the pressure and the better the efficiency of the conversion?

Re: How much power can we expect from rainfall?

#96
People need encouragement. Criticism can also provoke destructive reactions.

Weather is a source of tremendous energy. It just needs to be concentrated from the size of coastlines into something applicable to humans.

Here are some ideas:

1. Industrial processes which release particulates in the air go through a scrubber to produce nano capacitors.

The particulates fall to earth recovering energy.

The world's water now serves as the electrical grid. Produce the right digital signal and capacitors in the water release power.

2. A normally closed solenoid opens a cistern for water collection. After rainfall, the collector closes to prevent evaporation.

3. Rain water falls on a flywheel with magnetic bearings to reduce magnetic levitation and engage a clutch to a water wheel. Put on buoys in the water, or make something really large like a rail system.

4. Fertilizers and genetics recover the energy to turn the rain water into sugar or oil.

5. Mobile towers receive a rain sensor. Content changes to adjust human behavior, like slow down messages on the highway. Or limit wildfires in times of drought, such as raising the prices of lighters and matches.

Sometimes the best source of power is removing mistakes.

Re: How much power can we expect from rainfall?

#97

The point of science journalism is not to report on great science, or "speak truth to power" (the point of journalism). It is (like all other online publications) to get people to click on titles so they get shown adverts. It's not really got anything to do with how educated the readers are, it's just the business model. I read this after reading the article about banning "persuading" advertising. In my head the two…

> "speak truth to power" (the point of journalism) I think that might be a bit of wishful thinking. An "investigative journalist" might take that on as a motto, but it certainly isn't true of all journalism as a general goal.

Interesting. What is the point of journalism then?

Re: How much power can we expect from rainfall?

#98

Earlier quoted context omitted.

> "speak truth to power" (the point of journalism) I think that might be a bit of wishful thinking. An "investigative journalist" might take that on as a motto, but it certainly isn't true of all journalism as a general goal.

Interesting. What is the point of journalism then?

Obviously, that depends on where in the world you are. Assuming a press that is relatively free from government and adversarial editorial oversight, journalism can likely be summed up as "obtaining newsworthy information and publishing it to the public".

According to Wikipedia, at least, there are at least 242 ethics standards for journalism worldwide, with something of a general consensus on truthfulness, accuracy, impartiality and fairness.

"truth to power" may be a very narrow aspect (if, perhaps, an important one), but the simple fact is that there is plenty of newsworthy information that is fundamentally unrelated to struggles against powerful people, bureaucracies, political entities and companies. The "point" of journalism, then, is much simpler: gather information, attempt to filter it through a lens of accuracy and impartiality, and disseminate it. Not quite tautological, but there you have it.

Re: How much power can we expect from rainfall?

#99
post #83

I'm really skeptical about the claim that a monkey could generate 100W with a hand-crank. Serious human cyclists only produce 250-350W with their legs, and a monkey is tiny compared to that - and with only one or two hands?

The monkey number was a very rough order of magnitude comment, and shouldn't be taken too seriously. But: You’re technically correct — I didn’t actually look up the metabolic rate of monkeys. The average value for humans (2000 Calories / 24 hours) is approximately 100 Watts. Very quickly looking into it, rhesus monkeys are around 30-50 Watts average power (https://www.merckvetmanual.com/management-and-nutrition/nutr...), converting kcal/day into Watts. I don't know what their peak power is. Anyway, you'd need a few monkeys, but not hundreds!

Re: How much power can we expect from rainfall?

#100
post #79

Earlier quoted context omitted.

>Figured that tapping the drainage flow of water from a whole area combined would work better and for that need a organised drainage system all connected and yes you do get those. If I'm not mistaken, the technical term for these broad-area drainage systems is "river"

>If I'm not mistaken, the technical term for these broad-area drainage systems is "river" In some area's/countries - yes. What I was referring to would be your towns/cities and heck in the UK, we have most accomodation plumbed for water going in and out. Some countries/area's have what they call storm drains. Yes they all end up at the river, ideally for the sewage - after it is treated, though again mileage may vary…

Joking aside, the power of any water driven electricity generation is dependent on the difference in water levels on either side of the generator. Dams don't get built in deep canyons for convenience: the sites are chosen because they maximize the height of the water column.

The potential energy of a municipal sewage system, while not zero, since there is flow, is so small as to be useless, unless your city is bisected by a 400 foot cliff.

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