Monday, December 31, 2007

Solar Spheres

On a busy and darkening evening, I strolled down the streets of Hitec city, Hyderabad. Mammoth buildings, edifices, dazzling office spaces, lounges, non-stop air conditioning machines, ever running computers and servers, and on the whole the entire new city was a giant energy guzzler. As I reached the 13th floor of the service apartment in which I lived then, the entire Hitec city looked like Las Vegas, bleached with glaring lights! - all in a time where we proclaim about carbon control and global warming.

I called it a day as I was tired and retired to bed. But I was annoyed thinking where all this might lead us to. As I closed my eye, my thoughts drifted to a series of abstract possibilities and wired ideas. I wish to share it with all my environment conscious friends (green warriors) though this article.

We all know about super-conducting materials (those with zero resistance to conduction of electricity). What if we were able to make super-reflecting materials? Materials which are ultra efficient than mirrors and thus the quantum of energy impinging on the surface is always equal to the quantum of energy getting reflected. Thus the material remains to be in absolute inertness with respect to Electro Magnetic Waves.

So how would these materials behave?
Well, if you were to keep two super-reflecting mirrors facing each other, and if you were to focus a laser beam onto on of the mirrors for a fraction of a second, the ray of light from the laser would get reflected from mirror A to mirror B and back to A. This way the cycle repeats a number of times.
While in usual cases this series of reflection would die down in a fixed extent of time since the intervening air particles and to a minute extent the mirror surface would absorb the light.
But, when this experiment is conducted in absolute vacuum with super reflecting mirrors, the cycle would become endless, no matter even after millions of years.

Now how will this help us?
Let us construct a hollow sphere whose inner surface is super reflecting. On the north pole of the sphere, there is a unidirectional vent with a lid through which sunlight is allowed to enter for a fraction of a second. Since the space inside the sphere is devoid of air, this quantum of EMW would undergo an endless reflection spree. We could examine this activity if we place a CCD sensor on the south pole of the sphere. Since the CCD sends a pulse of electric current by converting the light which impinges on it, our energy inside the sphere would have a mild time-decay function. If we replace the CCD sensor with a solar cell, we are now generating power!

From a pragmatic propensity
Giant solar spheres can be manufactured in large scale. These structures would have larger uni-directional vents with automatic lids – perhaps of the kind of polaroids. A number of solar cells can be disbursed on the inside of the sphere - just like doping a semi-conductor. These cells would lie under smaller polaroid lids whose outer surface is also super-reflecting. Thus when the smaller lids cover the solar cells, the inside of the sphere is 100% super-reflecting.
Now, during the day time, we would open the top lid of the sphere allowing sun’s rays to enter the sphere close them instantly. Since the smaller polaroid lids cover the solar cells, the light inside the sphere would remain alive to eternity. Then, during the night hours (or during the needy hours) we would like polarize the smaller lids, thus opening the solar cells beneath to face the inside of the sphere. Whenever a quantum of light hits a cell after undergoing eternal reflection, it gets converted to electric current. This way until the last quanta of light is used up, we can generate solar power.

How good is our idea?
On a production scale, solar spheres would require nothing more than a few thousand solar cells, polaroid covers and our new super-reflecting material.
The following are the advantages

  • This method is maintenance free. Since the inside is vacuum, there is no means by which the apparatus could get damaged.
  • The outer shell can be made of steel / concrete as per the convenience and it is an one time investment.
  • There is no wear and tear.
  • The energy is 100 % clean without any emissions. Thus it is the safest source of power.
  • Energy can be generated instantly or could be stored up and generated after a million years too.
  • It is the best way to store electric power. Compared to super-conducting materials which should be maintained at sub zero temperatures, this ultra simple apparatus stores electricity with no loss for endless amount of time.

It’s quite conspicuous that Geo Dexter feels Solar Spheres would be the most feasible solution to our pressing demands of energy.

9 comments:

Unknown said...

Dear green warriors,
We all understand the dire necessity of a renewable, emission free source of energy. Super reflecting materials appear to be the cure to me.
I agree, my ideas might be wierd and outlandish. But at every point, I strive to pin them up with concrete scientific facts.
I request all of you to share your opinions about this article.
Thank you,
GeoDexter.

Author said...

very nice, creative!
Can you let us know the advantage over normal solar cell panels?
other than, the storage of energy as light for eternity.
Also, looks like the electric energy generated is proportional to the amount(intensity) of light entering. So if using polaroids(ideal unidirectoinal) you can leave the sphere open to incoming sun-light forever.
So in what way is it advantageous over solar cells? solar cells seem more economic now, since we dont need the polaroids and the yet to be invented ideal reflector(what conditions it may need to behave so, we dont know, it may need subzero temperatures as well right??)!!

Author said...

And as far as storing energy is concerned, this looks like a good idea for a huuuge intensity of light!

But storing solar energy as converted electricity(conventional method) for night, is there any advantage over that?
Overall i dont know whats better about this idea than existing solar cells? defend.

Unknown said...

Thank you Abigail, your comments are indeed thought provoking.

Sun is our source of energy and light from it, expands spherically. If we were to tap the energy from the sun in the form of light to the max extent, we would place our solar panels so that it forms a giant sphere around the sun with sun at its center.
If the solar cells were to be perfectly black, they would absorb all quanta of energy that impinge on them. If not, they would reflect the rest of the quanta. Now the question is where would this reflected energy go?
In flat panels, this reflected energy is essentially driven into the space. While in our sphere, this energy is focussed on to someother cell. Since the inner surface is double-concave, it acts as a converging lens too. Thus we are moving a step further towards maximum utilization of incoming energy.

Well, in today's world, this would sound unnecessary since we are yet to tap the solar energy even with flat panels. But this would find
pertinence when there is limited source of light energy. Say you had to generate current inside a cave where sunlight enters through a small vent.

Unknown said...

To Abigail
Regd keeping the sphere's lid ever open
Yes indeed, we could keep the sphere's lied ever open. The sphere would then be a trap to incoming energy. But this requires the vent to be ideal unidirectional (like u pointed out). If not, the vent could be transparent with an outer layer made of polaroids. Thus wherever we like polarize them they allow light to enter (as well as to exit) and when we corss polarize them, they remain opaque. This remains applicable to those smaller lids covering the random solar cells.

On the other hand, if we had ideal unidirectional lids, the need for a lid to the sphere is obviated. But we should also foresee of a condition when the rate at which the energy enters the sphere is higher than the rate at which it is used up. This would heat up the inside and under extreme conditions, we found find our panels melting in heat.

Well, we are now transcending into a solar powered stove.

Unknown said...

To Abigail
Solar sphere storage Vs conventional method.

Honestly, I am not aware of the efficiency of the currently available DC batteries. If they were to have 100% efficiency, then they compete equal with solar spheres. If not, you know which is better.

Anonymous said...

I read your replies, give me some time to think about them.
I know that total internal reflection is something you like,and is your cup of tea, but arent optic fibres doing the same thing?
so if our spheres are to look like tubes, impregnated with little solar cells? polarizing will not be necessary, expect at the mouths.
Also , this made me read about solar cells, there seems to be much more than a simple transducer there.
Read about it.

Solar cells have been my concern for some time, because they are expensive and dont help in green energy as expected.
So the ideal solution has to be much more cheaper. Nuclear energy is feasible since it gives out more energy(mega watts) with one installation.
Solar and wind are not so popular and not ideal means because of their cost and ungainly occupation of space which is scarce in our country.
we can see that people install windmills than solar cells in coimbatore. except in hotels for water heaters.
It would be nice to concentrate on cheaper solar cells.

But this idea of optic fibre has given me some hope of practical testing of your idea. lets think more deep about this.

Unknown said...

Hi Abigail,
I have this difference in opinion. I understood that total internal reflection happens when light gets reflected back in the direction of incidence. Thus the angle of reflection is very small (lesser than 15 deg or so). But if Optic fibres were to have total internal reflection, then light could not be transported from one end to another.
On the other hand, your visualization of an optic fibre doing the work of a solar sphere is a break through. Indeed a break through. they already exist (just that we need super-reflecting materials) and easy to store and use. Exactly, polarizing would be necessary only at the mouths.
I too need to read a lot on them. I have never worked with them further.

Your opinion about renewable energy is very practical. I read a science report in the paper and the author had exactly the same opinion. He even sighted the same reasons too.

Yes, I too believe, Optic fibres might give some degree of understanding about this hypothesis.

Starzzguitar said...

Seems to be a light perpetual motion machine, and the same problems would exist. However, it would be worth a try with or without photocells hooked up. I think rather than bother with sun input, use a laser to get it going. An experiment is necessary to see if this idea is feasible or not. Storing any power generated or getting it directly onto the "grid" is another problem.