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See-Through Solar Is Tomorrow’s Threat to Oil

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51–60 of 72 posts

Re: See-Through Solar Is Tomorrow’s Threat to Oil

#53

Earlier quoted context omitted.

Why couldn't you collect the solar energy from the outside of the window and put up blinds to block the light from the inside of the window? Putting up blinds won't generate any electricity.

What if we could design a solar cell that could shift from transparent to opaque on demand? Instead of putting up blinds, simply move a slider or tap a button or what have you, and suddenly the amount of light coming in is dimmed, and the energy being captured is increased. Seems like a win-win to me, if it were possible.

Solar-panel covered shuttering could do that.

Re: See-Through Solar Is Tomorrow’s Threat to Oil

#54
post #36

Good solar cells are 40ish% efficient? I'm not a photonics engineer but I wonder how much of the total energy is in the visible range. Current solar cells are only cost-effective in limited scenarios, it's nice that these could go in more places but even if they reach cost parity with what we have today, the would be less power. We're going to need to see huge reductions in production cost or energy capture before th…

Good research lab solar cells are 40% when actively cooled and concentrating light at 1000x. Good solar panels for homes and solar farms are 15 to 22% efficient.

It's interesting that efficiency is the key figure that we use. The more pertinent numbers are surely break even point - how many years in a standard installation to return the energy needed to make the panels. The next key figure is probably (in a domestic install) how much of a households energy can be produced with a standard install.

In many ways efficiency is irrelevant. If a panel were only 5% efficient but that produced 200% of a families power requirements in a normal install and broke even after 1 year that would be awesome. On the other hand if a panel were 95% efficient and returned 5% of families power requirements and broke even in several decades that would be terrible.

It seems a rating that shows how long it takes a panel under [a properly defined] "average" solar illumination to pay for it's own construction (both in money and power) would perhaps be useful and not too difficult to test and verify.

Re: See-Through Solar Is Tomorrow’s Threat to Oil

#56

Earlier quoted context omitted.

Only more reasons to stop using oil for energy and transportation - we need it for plastics.

I thought refining of oil was mostly separating the different hydrocarbons- or can gasoline be used to make plastic?

You can "crack" or "reform" any hydrocarbon to any other at the cost of some energy. Plastic tends to be ethane -> polyethylene, and the like. The fraction called "naptha" which is between ethane and gasoline in refining tends to be used as chemical feedstock.

Re: See-Through Solar Is Tomorrow’s Threat to Oil

#57
post #34

Earlier quoted context omitted.

Now your window needs wiring. And an inverter. Would be more effective to coat it or tint it or put up some blinds.

Why couldn't you collect the solar energy from the outside of the window and put up blinds to block the light from the inside of the window? Putting up blinds won't generate any electricity.

Well blinds would presumably block the light you want in (visual spectrum). Furthermore, anything that isn't reflected back out serves to heat the building. Absorbing the energy in a PV material takes some fraction of energy that would otherwise become heat and turns it into something valuable.

Efficiency is very important but just one-big factor to consider in your application. Less efficient panels can have other benefits that justify their use. Crystalline silicon panels are more efficient than thin film but thin films are lighter and so can be used on roofs that don't support the heavier panels.

Re: See-Through Solar Is Tomorrow’s Threat to Oil

#58

We are already struggling to make low cost solar panels that have a high efficiency using light absorbed from the visible spectrum (which accounts for most of the sun's spectral irradiation [1]). Furthermore, you can't just have solar cells that absorb a wide range of the solar spectrum, there is an optimum band gap for these materials of around 1.34 eV [2]. This means that the most popular solar cells in development…

You can't make single cells that absorb a wide range, but you can layer cells that absorb different spectras to achieve a much higher absorbtion in aggregate.

Re: See-Through Solar Is Tomorrow’s Threat to Oil

#60
post #38

so what would happen if you put the transparent panel on top of a normal panel?

It would lower to energy input to the lower, opaque panel. The transparent panel would "soak up" the infrared and ultraviolet energy first. The lower would only have access to visible light energy.
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