"Green" Batteries

[RedDevil]

Originally Posted by Awd180

Land Area (148,429,000 sq km) 29.1%
or 148,429,000,000 sq m not 148429000000 000

I knew you'd say that, I really knew!

One kilometer is 1.000 meters
One square kilometer is 1.000.000 square meters not 1000.
One cubic kilometer is 1.000.000.000 cubic meter.
Etcetera
If you square the unit you have to square the factor too.

My calculation is solid.

Originally Posted by Awd180

But still you get into functionality of a solar at a peak around the equator, why? Alaska has the longest days.

And the longest nights in winter. Over a year, half the time is daytime. This is true for any place on earth.
If you put the panels flat on the ground you use all the area there is. Best performance for the flat layout is on the equator.

Originally Posted by Awd180

Your figures don't account for error, weather, and rotational speed of the earth, the reports I've read are run from trial performance of solar cells in operation.

I set the average power output to just 10% of max output to account for all of that. A fixed panel could theoretically average ~30% (almost 1/pi) of max power per 24H in ideal weather, so 10% is very low, actually.

Originally Posted by Awd180

not to mention clearing that much land or the fraction that could contribute the amount of energy produced threw coal would be more damaging.

You mentioned covering the earth first and said it would not yield enough power. I show just over 1 % of land mass would do and you attack me on practicalities?

Originally Posted by Awd180

Solar cells are viable source for individual use but not a complete answer.

In ten years it may be the best choice, but for now it's not. You're finding variables but missing the other factors at play, there is and still is enough destruction of land for energy, industrial, and society.

Missing factors at play, me?
You said the earth would not yield enough power if it were completely covered.
I have shown it would have an abundance if you did that.
Then you blame me for showing you, fighting the (correct) calculation and completely missing the fact that I already compensated for rotation and bad weather.
Ah well. You did not get the facts right, should I expect then that my explanation would get a better treatment?

I second Neil's statement. My calculation used panels with less than 10% efficiency and another 10% over that for weather etc, and then using only land.
just a fraction of a % used of the potential energy (inn my calculation) can power the earth's yearly requirement in under 100 hours.
So the full load would do it within an hour.
It matches.

[IamIan]

Originally Posted by RedDevil

Such a pity those panels are so expensive, or else...

But , how expensive are they in the long run?
What is the Energy cost over the operational life time?

PV industry was able to dropped below $1/Watt years ago.

1 Watt x even just a conservative ~5 hours an average day x 365 days a year = ~1.825 kwh year one ... If we conservatively assume the PV will only just barely achieve it's warranty ... 80% by year 25 is industry standard ... although some have tested better than 86% by year 25 and others about ~70% of year one by year 40 ... but if we stay very conservative at just the 80% and only to year 25 ... that's a conservative average of ~1.46 kwh per year by years year 25 ... for an average of ~1.6425 kwh / yr for 25 years = ~41 kwh for ~$1 ... or $0.024 / kwh.

Even if we were to worsen that number a bit more ... to be even more conservative ... over the operational life time ... I would argue that Solar PV is already ... fairly cost competitive ... even financially... still getting better ... but it isn't horrible now when looked at in the longer time scale.

The issue has been ... most people think about their costs in much shorter time scale terms ... weekly ... or monthly ... so they aren't used to paying for ~25 years of electricity all at once ... but in the long run ... I think the cost is already fairly competitive... but I'm glad to continue to see the market trends for improvement.

- - - - - - - - -

Of course it can be much better than that in better locations ... Say instead of being overly conservative I were a bit optimistic ... say a slightly better made modern panel with a lower ~0.4% per year degradation ... I could optimistically still be producing over ~80% of year one , out to year 40 ... If I did that closer to the equator I could get on average about ~6.7 hours a day from a fixed array ... that could reduce the life time operational energy cost down as low as about .... For a fixed array ~$0.011 / kwh... not too shabby ... I pay a lot more than that now for Fossil fuel kwh.

[Xist]

As usual, I do not really know anything, but this is what I found through Google:

On the Equator, the duration of daylight is not exactly 12 hours all the year round, but rather — because of atmospheric refraction and the size of the Sun — exceeds 12 hours by about 7 minutes each day;

Day length - Wikipedia, the free encyclopedia



http://upload.wikimedia.org/wikipedi...ay_of_year.png

As for comparing length of day in Alaska and along the equator, according to Google, the (average?) latitude of Alaska is 64.0000° N and the axial tilt of earth is 23.4° (I wanted to make sure that I remembered correctly). So, in the middle of the summer, Alaska would have twenty-four hours of sunlight at 41.6°, while on the equator, you would have over twelve hours at 23.4°, while in the dead of winter, Alaska would not have any sunlight, while on the equator, you would have over twelve hours at 23.4°.

Oh, here is a cool toy! Daylight Hours Explorer

Plugging in 64° N, I get a longest day of 20.4 hours and a shortest of 3.6. Funny how that averages to twelve. For 0° N (or is that south?! :P), hmm, it shows twelve hours every single day.

However, there certainly seems to be more land at 64° N than the equator:

[RedDevil]

Originally Posted by Xist

... the (average?) latitude of Alaska is 64.0000° N and the axial tilt of earth is 23.4° ... So, in the middle of the summer, Alaska would have twenty-four hours of sunlight at 41.6°, while on the equator, you would have over twelve hours at 23.4°, while in the dead of winter, Alaska would not have any sunlight, while on the equator, you would have over twelve hours at 23.4°.

Nice!
But you got your centerpoint in Alaska beneath the arctic circle. There won't be a 24 hour day at 64° even at midsummer.
Furthermore you measured angles to the zenith instead to the horizon. In midsummer (or midwinter) at the equator the sun will reach a 66.5622° angle to the horizon.

The sun will reach a higher point on the equator than within the polar circle. The average height of the sun during 24 hour will not be more than 23.4° within the polar circle. At the equator it will be 0°, but over the 12 hours of daylight it will average way more of course, so the total amount of light is almost the same.
The area that gets the most light in summer is the temperate north zone; the USA & lower Canada, Europe, etc. The sun gets almost as high as at the equator but the days last significantly longer.

[Xist]

Originally Posted by RedDevil

Nice!
But you got your centerpoint in Alaska beneath the arctic circle. There won't be a 24 hour day at 64° even at midsummer.
Furthermore you measured angles to the zenith instead to the horizon. In midsummer (or midwinter) at the equator the sun will reach a 66.5622° angle to the horizon.

The sun will reach a higher point on the equator than within the polar circle. The average height of the sun during 24 hour will not be more than 23.4° within the polar circle. At the equator it will be 0°, but over the 12 hours of daylight it will average way more of course, so the total amount of light is almost the same.
The area that gets the most light in summer is the temperate north zone; the USA & lower Canada, Europe, etc. The sun gets almost as high as at the equator but the days last significantly longer.

Ah right, I had forgotten what the Ant\arctic Circle defined! Also, I always get things backward!

[RedDevil]

Originally Posted by me

Such a pity those panels are so expensive, or else...

Originally Posted by IamIan

But , how expensive are they in the long run?
What is the Energy cost over the operational life time?

That was just meant as a stepup to the cheap printed solar cells.
Your comments are very true of course, but changing technology bringing the cost down to a fraction of current cost would blow everything else away. Electric energy would be almost free.

Bizarrely that same article crosslinks to an article about rechargeable flow batteries, bringing this subject back on topic....
Both reads are worthwhile imho.

[guudasitgets]

Revisiting a post from 2013 to prove a point, this guy apparently is telling me what "I" should have bought ,

Originally Posted by IamIan

Back in 2008 you had better options to reduce your own personal life time pile of pollution.

And my reply

Originally Posted by guudasitgets

Seriously?
So now you know more about what my finances were like back then? Like I almost lost everything and had pretty much $500 dollars to my name and 300 of it I spent buying that car and one week later I started driving it and started my road back to recovery.

Nope couldn't buy a Prius for $300 bucks, But if you want to mail a check and start buying cars for me I'm all ears.

And the moral of the story, from that day back almost 4 years ago to now. And you notice in 4 years he never answered my question, What could I have bought that was a better choice? Nor offered anything but criticism

Moral of the story? People that are like this like to talk a good game trying to tell you what you "SHOULD" do; when in actuality they really are dumb to your situation and don't know anything and won't offer anything but criticism. He must drive to work on compressed air