The effect of colored light on a solar panel?
This is for my science project and i cannot figure it out
We assumed that blue light shining on a solar panel would give off the higher volt reading because it has the shortest wavelength and the highest energy, but it was actually the lowest.
Why does this happen? Im very confused And cant find the answer anywhere…. ?thank you!!
The short answer is that your solar panel can’t ‘see’ that blue light very well because of the limitations of its spectral response..
The ability of something to capture energy is not just determined by the strength of the energy, but by what the thing is able to catch or ‘detect’. This is most often related to the energy’s frequency/wavelength. The types of energy (as in color, frequency, wavelength) a device can detect is called its ‘spectral response’. This is often given as a numerical range of wavelengths (frequencies, or colors), but it’s best to see it as a graph. That way, you see what energy bands it can detect, which are not always next to each other, and how well it can see these energies. To make this clear, let’s consider the human eye. It also has a spectral response. It happens to peak around the green, and yellow-green range of wavelengths. So we can see those colors better. If we looked at a bunch of lights of all colors, and those lights were putting out the same amount of energy, the green ones would look brighter to us, just because we can see them better. A blue or purple light would have to put out a whole lot more energy for us to see it as brightly as green or yellow one. This is a human limitation. Other creatures and devices see/detect things differently. Dogs can hear things we can’t. Owls can see things we can’t. Bats are nearly blind by our standards, but can ‘see’ sound so well, they can catch mosquitoes in flight. Fish can ‘see’ electricity with sensors that run along their sides. So, even though ultraviolet light is more energetic than green light, we can’t see it. Higher energy ‘light’ like x-rays and gamma rays, can’t be seen by the human eye either. (Although x-rays stimulate my retina, allowing me, and a few others to ‘see’ them with our eyes closed!) The specifications of your solar panel includes it’s spectral response. It may be a graph in the documentation that came with it, or you might be able to find it on the internet. But the wavelength/color that corresponds to the highest peak of the spectral response graph, will be the type of light that particular panel can best convert to electricity.
Have fun!
Oh. just for fun, try this! Look at the front of a TV remote control through the screen or electronic view finder of a camera, and push the remote’s buttons! Remotes send out infrared light.