All so called Natural Generation methods have consequences …

[fizzy]

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solar water bottle lights

 

[Robert Weaver]

PV cells have efficiency peak in the visible wavelength. The UV and IR regions of the spectrum have only a small contribution.

Photosynthesis happens around blue and red (450 and 650 nm).

The introduction of PV cells doesn't change the rate of heat absorption or transmittion, but we're now converting visible light (that would have previously been "inert" to the planet's energy balance) into electrical energy. This will inevitably lead to a greater net energy input, and ultimately warming of the planet.

 

[Gareth J]

I have always wondered why a roof is so dark. It would make a big difference making them reflective - perhaps changing to dark for the winter.
Cities would be a lot cooler and it would save on vast amounts of energy.
Particulates in the atmosphere can reflect a lot of heat - hence the term nuclear winter. Also volcanic eruptions can have the same effect.

There have been "white roof" projects, though I don't think they've got very far.

David Adam: Paint roofs white to slow climate change, say scientists. Radical or ridiculous?

Painting your roof white could help slow climate change by reflecting sunlight back into space. So would painting the moon and covering the desert in plastic sheets. Wild eco-goose chase or radical thinking?

www.theguardian.com

PV cells have efficiency peak in the visible wavelength. The UV and IR regions of the spectrum have only a small contribution.

View attachment 301600

Photosynthesis happens around blue and red (450 and 650 nm).
View attachment 301601

The introduction of PV cells doesn't change the rate of heat absorption or transmittion, but we're now converting visible light (that would have previously been "inert" to the planet's energy balance) into electrical energy. This will inevitably lead to a greater net energy input, and ultimately warming of the planet.

I think that's the explanation of Miranda's point. But! If PV is displacing fossil fuels, which were stored, out of our energy system, digging them up and burning them (releasing their stored energy into our system) they also add energy. They also add CO2 which obviously compounds issues. Which is least bad?

 

[Robert Weaver]

Increasing heat by utilising previously unused visible light, or increasing heat by burning dead dinosaurs and liberating co2; probably a PhD in there somewhere.

 

[hotponyshoes]

People using energy in ever-increasing amounts is the problem.
Regardless of how we produce the energy, unless we set in motion plans to use less of it, we will eventually be doomed.

We can come up with countless new ways to capture natural energy and convert it to a fork that's useful to us but as long as we keep increasing our usage of it then we are always going to have a problem as the only way we have of distributing it and creating more "stuff" that runs on it is to use more natural resources.

The problem with natural resources is that they are free therfore there will always be people willing to exploit them to make a profit.
And people willing to pay them to do that.

Sure, I could get up an hour early tomorrow to wander up the woods and collect some puddle water and a few sticks then come home and make myself some environment friendly nettle tea.
What I will actually do is make some instant coffee (imported from half a world away) using a kettle made in China with water that's pumped to my house.

I might think I'm helping the situation by only "boiling what I need" in the kettle but I will probably have 3 cups before I leave the house in my diesel van with the air-con on.

I might even just fill the kettle to the brim to save me refilling it twice. Potentially I might feel guilty about doing that but then I might question just how many times I would have to "just boil what I need" to offset just one of eltons rocket launches?.

 

[hotponyshoes]

In fact, people in general are the problem.
I'm eating a prawn sandwich for lunch.
Unbelievably, it has over 35 individual ingredients!!
What on earth is the environmental cost of getting all that stuff grown, processed and moved to the sandwich factory?
Then it has to be taken to the garage and kept in the fridge that's running flat out to maintain 3deg in 28deg weather for me to drive in my van and pick it up.
That's just the ingredients. People are driving to the factory to operate the sandwich machines and then there is the packaging not to mention that I also have a bag of crisps and a can of drink.

This won't be the only thing I eat today and I will probably continue to eat every day for as long as I can.
The couple of solar panels I own are probably not my greatest impact on the sustainability of the planet.

 

[mike os]

No, you're not wrong per say. As has been mentioned as most panels are very dark, they'll absorb more radiation than a whiter surface. They, in big expanses, will also "insulate" the earth from radiating some of its energy away to the night sky and reduce ground wind speeds. Resulting in local heat island effects.

surely if the panels are insulating the ground it does not get as hot therefore does not have the capacity to radiate.......

 

[mike os]

white or black body absorption and radiation is net neutral.... reflected and it heats up what its reflected at, absorbed it radiates the same heat later when the equilibrium changes, the net heat is still the same... roughly

white bodies warm slower but also radiate slower....

 

[mike os]

I'm eating a prawn sandwich for lunch.
Unbelievably, it has over 35 individual ingredients!!
What on earth is the environmental cost of getting all that stuff grown, processed and moved to the sandwich factory?
Then it has to be taken to the garage and kept in the fridge that's running flat out to maintain 3deg in 28deg weather for me to drive in my van and pick it up.
That's just the ingredients. People are driving to the factory to operate the sandwich machines and then there is the packaging not to mention that I also have a bag of crisps and a can of drink.

This won't be the only thing I eat today and I will probably continue to eat every day for as long as I can.
The couple of solar panels I own are probably not my greatest impact on the sustainability of the planet.

this...

if you want to make a real impact look at what you eat, where its grown, how it got here..... give up your tropical fruits, foreign beers, and other such nonsense, eat local and in season and you will have a far greater impact than most, forget foreign travel other than as a rare luxury... move closer to work,

because quite frankly technology will not solve this problem......

 

[Bryan Williams]

In fact, people in general are the problem.
I'm eating a prawn sandwich for lunch.
Unbelievably, it has over 35 individual ingredients!!
What on earth is the environmental cost of getting all that stuff grown, processed and moved to the sandwich factory?
Then it has to be taken to the garage and kept in the fridge that's running flat out to maintain 3deg in 28deg weather for me to drive in my van and pick it up.
That's just the ingredients. People are driving to the factory to operate the sandwich machines and then there is the packaging not to mention that I also have a bag of crisps and a can of drink.

This won't be the only thing I eat today and I will probably continue to eat every day for as long as I can.
The couple of solar panels I own are probably not my greatest impact on the sustainability of the planet.

And the prawns were probably cought by slaves on Thai 'ghost ships'..

 

[Gareth J]

white or black body absorption and radiation is net neutral.... reflected and it heats up what its reflected at, absorbed it radiates the same heat later when the equilibrium changes, the net heat is still the same... roughly

white bodies warm slower but also radiate slower....

Hmm, good points.

It's been a very long while but isn't the reason that it's not a net neutral effect because, while whiter objects absorb and emitt less, dark bodies absorb more higher wavelengths but then emitt them at lower (IR and the like) wavelengths which, unlike the higher wavelengths, warm the surrounding air more readily? So that while of course emission/absorbtion is in balance, the net effect is a warmer local environment if you surround yourself with black things.

Like I said, long time though so happy to be put right.

 

[hotponyshoes]

There is a big molten bit inside our planet that is gradually cooing down so that heat must be going somewhere.
I would guess it rises to the surface and drifts off out into space.
No idea what sort of % difference covering the surface of the earth would do to that?

Although I don't think global warming is a good idea all we have to do is wait long enough and the universe will eventually hit equilibrium at a constant temperature.
I don't think it will be a temperature that will support our lifeforms but there is not much chance of us still being around for that anyway

 

[mike os]

Hmm, good points.

It's been a very long while but isn't the reason that it's not a net neutral effect because, while whiter objects absorb and emitt less, dark bodies absorb more higher wavelengths but then emitt them at lower (IR and the like) wavelengths which, unlike the higher wavelengths, warm the surrounding air more readily? So that while of course emission/absorbtion is in balance, the net effect is a warmer local environment if you surround yourself with black things.

Like I said, long time though so happy to be put right.

Like I said, roughly.....

 

[Miranda]

And we can’t get rid of it back into space, so it makes sense that the planet is warming up, because of all the energy it is absorbing.

Exactly so. Exacerbated by trapping even more of it.

 

[Miranda]

But we are not trapping heat, heat is reflected off


What we are is capturing light

We are trapping more energy than the same area of earth would have been under agriculture or forests etc.

 

[Miranda]

The way that we could stop global warming is by stopping 7% (ish, this was what it was discussed about when I was at uni in 2004 -2008) of the light (or electromagnetic radiation) hitting the earth, this could be done by solar shading like a small number of satalites blocking the sun. Or as was suggested on one lecture the application of milk powder to the atmosphere (this is not exactly going to work but it was suggested) Alternatives were doing things like painting all roads white and all rooves white its a thing called the Albedo effect

Yeah….. we’ve been great at things like this without understanding unforeseen consequences.

The Saudis are seeding the sky as we speak to bring about rainfall. so you take that water out of the sky……. Anyone have any idea at all where that might lead … particularly if everyone else says “well the Saudis are doing it, we should too “

 

[Miranda]

What's the crusade?

I would fully support anybody who said the science shows global warming is real, is bad news, and should be stopped if possible.

At the same time I'm not going to get rid of my fridge and walk down to the nearest farm every day to get a pint of milk in exchange for half an hours farm labour then return to my house and heat it on a wood fire.

You do seem to be doing more than me by having a 10kw array and using it to charge your car up.
But I'm going to carry on driving my diesel van around to work until I can afford to buy a house big enough to put a 10kw array onto

My array is doing the earth more harm than good, but individually, we as a family are doing well out of it.

that is THE big problem, or actually one of the many small ones

 

[Miranda]

It's because you're talking nonsense @Miranda

Yeah … ok

 

[Miranda]

Just been reading, the sun delivers more energy to earth in one hour, than that delivered by all the fossil fuels we consume in a year.
Perhaps our scientists/engineers should be looking into ways of collecting energy in equitorial regions & transferring it to more temporal/colder regions. Probably more doable than creating fusion reactor generation.
RonA

hey.

That was the whole point of this thread.

collecting energy…. Means a hotter earth

 

[mtt.tr]

Remove fossil fuels use solar and the net produce will be reduced global warming gasses