Jim Logajan wrote:
wrote:
Andrew Sarangan wrote:
There is 30 horsepower of solar radiation falling on a Cessna 172's
wing that we are simply throwing away.

Unless I dropped a decimal somewhere, there is about 16 M^2 of wing
area on a C-172.

At ~1000W/m^2 insolation, that yields an "ideal" max power of ~16,000 W.

30 HP is 22.4 kW; there isn't that much energy in sunlight.

Since there are ~746 W/HP, by my reckoning the sunlight power on a C-172
wing is ~21 HP. Still not bad, though not sure where Andrew got 30 HP.

He's using 1.4 kW, which is about the max you'll ever get.

Both of you are ignoring the fact that you get that only if the angle
beteen the sun and your collector is 90 degrees, otherwise you have
to multiply by the sine of the angle to get the real energy per unit
area.

The challenge is extracting the full solar spectrum and storing it.
But there are no fundamental scientific reasons why this is not
achievable.

You mean other than we haven't a clue how to do it in the real world?

There are no fundamental scientific reasons why we can't:

Convert light into electricity with 90% efficiency.

Real world system efficiencies of 40% should be possible today - using
solar thermal (e.g. solar troughs).

Lab efficiencies are already around 40%.

Using collectors or concentrators doesn't change the overall efficiency,
it only makes the area of the converter required for a given amount
of energy smaller; the total area remains the same.

And for photocells, it runs the temperature up which plays hell with
the usefull life and reliability.

Cure cancer.

That is already being done for some forms of cancer. Next time try "Cure
the common cold." (And strictly speaking the body does that on its own - it
just makes you feel miserable while it goes about it!)

Cure cancer as in take these pills twice a day for a week, not irradiate
or cut out a chunk of the body and hope there isn't too much collateral
damage to the body, though with stuff like proton therapy the irradiation
stuff is getting pretty good.

Produce sustainable fusion.

Always 30 years off.... ;-)

Convert junk mail and coffee grounds into 100 LL.

An interesting idea. :-)

Mr. Fusion; I forgot about the banana peels.

--
Jim Pennino

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