Naked Science Forum

Non Life Sciences => Technology => Topic started by: Felicia on 11/10/2010 09:30:05

Title: Is solar energy the same as light energy?
Post by: Felicia on 11/10/2010 09:30:05
Felicia asked the Naked Scientists:
   
Is solar energy same as light energy?

What do you think?
Title: Is solar energy the same as light energy?
Post by: Geezer on 12/10/2010 04:51:26
Not entirely. A lot of the energy radiated by the Sun is in the form of "light", i.e. it is visible to humans. But a lot of the energy is invisible to us, because its frequency is outside the visible light spectrum.
Title: Is solar energy the same as light energy?
Post by: robertjhon143 on 13/10/2010 10:19:05
solar energy is not the same as light energy.yes i am agree with Geezer
Title: Re: Is solar energy the same as light energy?
Post by: Blunt Zhou on 02/06/2019 03:07:27
The two are definitely different. Solar light is more energy-efficient and environmentally friendly than ordinary lighting, and the lighting is brighter.
Title: Re: Is solar energy the same as light energy?
Post by: evan_au on 02/06/2019 03:35:00
Quote from: Geezer
its frequency is outside the visible light spectrum
SIlicon solar cells with a bandgap around 0.7V are able to produce useful energy from infra-red photons with energy above 0.7eV.

The extra energy in visible photons is actually wasted by Silicon solar cells. Higher efficiencies have been achieved by directing higher-energy photons to a different semiconductor with a larger bandgap, producing "tandem" solar cells with a total efficiency of over 35%.

Quote from: Geezer
But a lot of the (Sun's) energy is invisible to us
The Sun's electromagnetic emissions also occur in infra-red and ultraviolet (with some in X-Rays and radio waves). Calculations suggest that it takes around a million years for this energy to percolate from the nuclear furnace in the center to the visible surface that we see.

But there is a about 3% of the Sun's radiation which is not in the form of electromagnetism at all, but in the form of neutrinos.

These are not blocked by the Sun's incredibly dense core, and reach the Sun's surface in about 1 second - and hit the Earth about 8 minutes later. There are enough that interact with matter that we can actually detect that they are present. But they interact with matter so weakly that nearly all go straight through our solar cells, and indeed straight through the whole Earth, and we can't use them to generate useful energy.

See: https://en.wikipedia.org/wiki/Solar_neutrino
Title: Re: Is solar energy the same as light energy?
Post by: Bored chemist on 02/06/2019 10:05:58
Is there a facility for removing the "marked as best answer" highlighting?