How much energy is transfered?

[ANAHUAKMA]

Hey guys new here and I've got a question. If you had a 250mw laser and pointed it at a solar panel then measured the energy transfered, what would the measurement be? Ex. Football field = Yards. Transfered energy from laser = ???

 

[Laser Smith]

Uhhh.. Get an lpm
And some goggles

 

[Cyparagon]

That depends on the efficiency of that particular panel at that particular wavelength. Somewhere around 5-20% is typical if I remember correctly.

 

[grainde]

You need to do an IPCE measurement to determine that. IPCE stands for incident photon to current conversion efficiency. There are many, many loss factors affecting the absorption of a photon and the ultimate conversion of that photon to an electron in the solar cell. Basically the answer to your question is not very much at all ie especially for a large solar pannel! If you just want to see if you can register something ok but youll probably be in the microamp range...If you use a very small test cell, eg 1cm2, which can be completely illuminated by your beam youll be able to measure much higher values. It will depend on the intensity of illumination at the pannel or junction rather than the intensity of the source ie distance plays a crucial role. If you really are interested, I can send you a few papers on IPCE and IV measurements for solar cells. :beer:

 

[Bionic-Badger]

People were creaming their pants when efficiency jumped like 1-2% with solar panels. Don't expect much.

 

[ANAHUAKMA]

You need to do an IPCE measurement to determine that. IPCE stands for incident photon to current conversion efficiency. There are many, many loss factors affecting the absorption of a photon and the ultimate conversion of that photon to an electron in the solar cell. Basically the answer to your question is not very much at all ie especially for a large solar pannel! If you just want to see if you can register something ok but youll probably be in the microamp range...If you use a very small test cell, eg 1cm2, which can be completely illuminated by your beam youll be able to measure much higher values. It will depend on the intensity of illumination at the pannel or junction rather than the intensity of the source ie distance plays a crucial role. If you really are interested, I can send you a few papers on IPCE and IV measurements for solar cells. :beer:

So what your suggesting is to use a small cell to get an actual reading?

 

[grainde]

Well yes, but youll need a very small and efficient single test cell, which Im not sure you could easily obtain. You would also need to illuminate it from close range ie make sure that the spot covers the active area of the cell exactly. If you have too much divergence over the distance the light will be much less intense and you wont have your 250 mW.
A photosensor shielded from the ambient light, and rated for that power, might be a better option. If you told us exactly what you planing to do, it might be easier to help you. :beer:

 

[Things]

If your intentions are to create a laser power meter using solar cells, don't bother, there are simply too many factors to take into account to make it work reliably. That's why you'll find 95% of LPM's on the market are thermal based.

 

[sedstar]

I am slowly waking up a part of my brain that used to do digital logic and electronics a lot... i idly wonder what the speed of current/voltage rise in the output of such a photovoltaic cell would be.

if it were fast eough, he could form a project with modulation. Even if not, there's always the thousand yard doorbell, so to speak.

 

[Bionic-Badger]

Did you happen to notice that the last post was over half a year old?

 

[sedstar]

oops...