Stacking ~~~~anyone heard of this new technology ?

[Jmac00]

http://sourceable.net/stacking-method-enhances-solar-power-efficiency/

I read this article three times and I still can grasp what they are doing?

The stacking method involves placing several solar cells on top of each other, and is at present the most efficient form of social power installation on the market, capable of converting 45 per cent of the sun’s energy they harvest into power. -

How do they stack panels and still get sun to the bottom cell.

[russ]

Just some fool trolling university websites and writing about something with zero knowledge. Will such a thing ever see the light of day? Today no one knows.

[SunEagle]

http://sourceable.net/stacking-metho...er-efficiency/

I read this article three times and I still can grasp what they are doing?

The stacking method involves placing several solar cells on top of each other, and is at present the most efficient form of social power installation on the market, capable of converting 45 per cent of the sun’s energy they harvest into power. -

How do they stack panels and still get sun to the bottom cell.

It is one of the research areas of trying to get as much of the light striking a solar cell converted to energy. The photons from the sun pass through material and keep going. Having another layer of semiconducting material below the first will get some of that solar energy to produce electrons. The trick is to find a "cheap" material that generates electricity and then make layers of it to capture as much energy as possible.

Other forms of research use lenses to concentrate light onto the cell like a magnifying glass. More light means higher production but also means more heat which is not good for solar cells.

The stacking has some potential to get additional efficiency % but I think the 45% is a leap. I would suggest for you to watch and read but don't invest in these methods.

[pleppik]

http://sourceable.net/stacking-metho...er-efficiency/

I read this article three times and I still can grasp what they are doing?

The stacking method involves placing several solar cells on top of each other, and is at present the most efficient form of social power installation on the market, capable of converting 45 per cent of the sun’s energy they harvest into power. -

How do they stack panels and still get sun to the bottom cell.

The writer doesn't do a good job of explaining what this is about or why it might be useful, so let me give it a stab.

The first thing you need to understand is that the energy in light comes in discrete bits called photons. Each photon carries a specific amount of energy, corresponding to the color of light it carries. A photon of violet light has approximately twice as much energy as a photon of red light, and white light is made of a mixture of all the different colors.

A semiconductor solar cell is a device which can absorb a photon of energy and transfer that energy to an electron. The amount of energy it transfers to each electron is the voltage, and the number of electrons it gives the energy to is the current.

The thing is, the active part of a solar cell (the p-n junction) can only transfer a specific amount of energy to each electron as useful electricity (the amount of energy which can be turned to electricity in one electron is called the bandgap, and is measured in a unit of energy called electron-volts). You can manufacture the cell differently so it gives different voltages, but once the cell is manufactured it can't be changed (with current technology).

If a photon hits a solar cell with too little energy (i.e. the photon is too red), then the cell can't pass it to an electron. The photon might be reflected, it might pass through, or it might just get absorbed as heat and not useful electricity.

If a photon hits a solar cell with too much energy (i.e. the photon is too blue), the energy gets passed to the electron, but the extra energy just becomes heat. So the only light which can be turned into electricity with 100% efficiency is the light at exactly the right color to match the bandgap of the p-n junction. This is the major limitation on solar cell efficiency.

One idea for getting past this, which has been in the lab for a long time and is commercially available in some specialty (read: very expensive) solar cells, is to stack multiple p-n junctions vertically in a single cell. On top you put a junction tuned to capture blue photons and allow lower energy light to pass through. Below that you put a p-n junction to catch yellow photons, and so forth.

So this article is really about someone developing a new way to do this. Figuring out how to stack p-n junctions on a single solar cell that's both inexpensive and efficient is important for getting more watts per dollar. It's less clear if this technique is particularly novel, efficient, or inexpensive.

[inetdog]

So far the use of multiple junction types in a single assembly is only economical for applications like space and military where it is necessary to get the most power possible from the available space rather than to get power at the lowest cost.

[Jmac00]

The writer doesn't do a good job of explaining what this is about or why it might be useful, so let me give it a stab.

The first thing you need to understand is that the energy in light comes in discrete bits called photons. Each photon carries a specific amount of energy, corresponding to the color of light it carries. A photon of violet light has approximately twice as much energy as a photon of red light, and white light is made of a mixture of all the different colors.

A semiconductor solar cell is a device which can absorb a photon of energy and transfer that energy to an electron. The amount of energy it transfers to each electron is the voltage, and the number of electrons it gives the energy to is the current.

The thing is, the active part of a solar cell (the p-n junction) can only transfer a specific amount of energy to each electron as useful electricity (the amount of energy which can be turned to electricity in one electron is called the bandgap, and is measured in a unit of energy called electron-volts). You can manufacture the cell differently so it gives different voltages, but once the cell is manufactured it can't be changed (with current technology).

If a photon hits a solar cell with too little energy (i.e. the photon is too red), then the cell can't pass it to an electron. The photon might be reflected, it might pass through, or it might just get absorbed as heat and not useful electricity.

If a photon hits a solar cell with too much energy (i.e. the photon is too blue), the energy gets passed to the electron, but the extra energy just becomes heat. So the only light which can be turned into electricity with 100% efficiency is the light at exactly the right color to match the bandgap of the p-n junction. This is the major limitation on solar cell efficiency.

One idea for getting past this, which has been in the lab for a long time and is commercially available in some specialty (read: very expensive) solar cells, is to stack multiple p-n junctions vertically in a single cell. On top you put a junction tuned to capture blue photons and allow lower energy light to pass through. Below that you put a p-n junction to catch yellow photons, and so forth.

So this article is really about someone developing a new way to do this. Figuring out how to stack p-n junctions on a single solar cell that's both inexpensive and efficient is important for getting more watts per dollar. It's less clear if this technique is particularly novel, efficient, or inexpensive.

Thank you for that explanation, your explanation is soooo much better than the article.