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Hi All,
I started this thread in the heat-to-electricity forum because I couldn't figure out a way to create a forum for light-to-electricity stuff.
Here I'll put forward some ideas and inventions for improving solar panel performance. I deliberately exclude any ideas that require modifying the semiconductors.
1) the Dahlberg patent, already brought up in the thermoelectric context. The concept is very simple--so simply it took me years to understand it :-) Dahlberg was a renowned solar cell researcher in the 70s and 80s, and at one time the head of Telefunken's solar cell division (mostly devoted to satellite applications because there was no commercial solar cell market at that time.) Dahlberg uses switches and diodes to put any sort of 'direct energy conversion' device (ie solar cells, thermoelectric elements, thermionic diodes, etc.) into an AC circuit with capacitive reactance. This allows the through current of the converter element to be controlled, reducing losses. He claims a solar panel output from the device shown in fig. 6 that is nearly equivalent to Voc * Isc. This is well above the efficiencies available in commercial solar cells. I recently realized as well that the use of an AC input as the patent shows would mean that solar power that was to weak to turn on a standard controller could also be used to generate power, scooping up considerable light that is now wasted in the early morning and late evening. Since this concept is relatively easy to test, and doesn't require extensive modification of the panels themselves, I put this first and foremost among solar concepts to be tried.
2) Using an electric field across the solar panel to enhance output. Some papers on the effects of electric fields on solar cells, as well as some types of experimental cells, lead me to think that high E-fields would have a wavelength selective effect on solar panels, at the same time increasing the Voc. The wavelength selection mimics what is seen in composite cells which have increased output. Sometimes having too many wavelengths impinging on the cell actually increases the amount of thermal phonons that are generated. One way to use an E field, without missing out on wavelengths not selected, would be to sweep the E-field up and down through a range selecting the whole spectrum of visible light during its transit. Once again, there are only hints, and bits and pieces in the literature, but I have a strong hunch that this is could lead to some interesting results.
3) I've mentioned before that the capacitance of solar panels shows wide divergence under different light conditions. There are a number of ways to use this capacitance variation in ferroelectric energy harvesting or parametric amplifier applications. One simple way would be to simply charge the panel at moments when C was high, and discharge it when C was low--identical to ferroelectric harvesters like the Zaev device, or many others. I believe this could only be done at night, when the panel was not operational. But there may be more sophisticated ways to get this additional parametric output from the solar panel even while it is producing its DC output.
There are couple of other possibilities but these are three most likely in my opinion. I'll put in references later today-- right now I have to go do some errands.
Regards,
Fred
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Author
Topic: New Solar Concepts (Read 1280 times)
