Energy from moonlight?

[Cairenn]

This just showed up on my wall. I know I won't have any time to research it, until next week. It seems dodgy to me at first glance.

http://inhabitat.com/rawlemon’s-sph...lobes-can-even-harvest-energy-from-moonlight/

 

[Pete Tar]

It looks pretty cool, but it seems to just be an awesome magnifying glass.
Nothing wrong with it, they don't seem to be claiming anything more than that it's a really good light focuser.
The 'energy from moonlight' line just seems to be how good it is at focusing light, so a low light source can be turned into a usable one. They don't seem to have worked on how to turn that light into usable energy yet.
Not much information on the website. Just seems to be a promising improvement.
"Thermal applications"? Maybe creating steam for a turbine?

 

[Pete Tar]

A page discussing whether solar panels can turn moonlight into energy.

http://www.wisegeek.org/is-it-possible-for-solar-panels-to-charge-in-the-moonlight.htm

This comment below the main article gives some numbers...

Direct sunlight in the tropics is about 250 watts per square meter (averaged over night and day, without accounting for cloud cover). The moon only produces 0.00146 watts per square meter of direct light energy when measured from sea level in the tropics with the moon directly overhead.The difference between the radiation from the sun and the moon in the tropics is over 170,000 times. This would make it physically impossible for a solar electric panel array rated at 135 kW to pull five or six kW from the light of a full moon. This represents a difference of only 27 times, nowhere near the ratio of 170,000+ to 1 that would be possible. The theoretical maximum (not taking into account things like temperature, air density, etc.) would be more along the lines of 0.8 watts (0.008kW) from this array.

I guess if you times that .8 watts by the claimed 10 000 increase, you would get 8000 watts?

The advantage of a clear sphere means it doesn't need to turn to face the sun, but it seems it would overheat any solar panel underneath it pretty quickly.

(unrelated)
Why is turning water to steam the preferred method for driving a turbine? Aren't there substances with a lower boiling point that would require less energy to heat to turn into gas? Will they not have enough pressure (lower density)?

 

[jaydeehess]

Just guessing but, Water is a plentiful, well understood, and inexpensive liquid that causes no environmental issues if spilled.

 

[jaydeehess]

8KW from moonlight sounds unduly optimistic to say the least.