Fresnel Lens Focal Length Change with Water, Concentrated Solar Power

This is a raw unedited video in realtime demonstrating the physics of light through a Huger Fresnel Lens. As water is added to the Fresnel side of the lens, the Focal Length triples due to water filling in the grooves of the lens. The optical quality is reduced causing the light to spread over a larger area. The overall energy concentrated is the same (less water filtering). This solar Fresnel Lens with a 40" focal length increased to almost 9 feet or 108"

Category:

Science & Technology

Tags:

• SOLAR
• TRAINING
• TEACHING
• STUDENT
• DEGREE
• ALTERNATIVE
• ENERGY
• FRESNEL
• LENS
• GREENPOWERSCIENCE

[muddymuddymuddmann]

hEY DAN, I LOVE THE ONE I GOT FROM YOU. IT HAS ENTERTAINED ME WELL. I HAVE COOKED HOTDOGS ON IT AND MADE COFFEE AND I TRIED TO COOK SOME FISH BUT I REALLY FRIED IT .

I MADE A COVER FOR MINE AND A PRETTY GOOD STAND. ITS NOT AS PRETTY AS THE FRAME YOU MADE BUT ITS STURDY. AND ADJUSTABLE. I TRIED THE WATER THING AND GOT RESULTS OF ABOUT SEVEN FOOT. IT RUNS MY ENGINE REAL GOOD. THANKS

MUDDy

[GREENPOWERSCIENCE]

:-) Thanks MUDDy

If we every get wind here in FL I will test your turbine design. Looks really good, I just need wind.

Dan

[Ragrog105]

I didn't realize that about Fresnel lenses. Thanks for the demonstration.

[madjimms]

Another great video, I love our beloved Sol......

Oh & I enjoy Dan to!

PS:where is your wife lately?

[ringonian]

so water defeats the purpose of a solar collecting project due to changing its focal point. is it possible to keep the focal point uniform? maybe placing a straight glass pane in front of the fresnel lens similar to a dual glass window? or maybe placing another fresnel lens behind the other (short of the focal point, possibly) similar to a telescope?

[Raycheetah]

Thanks for the safety tip, Dan. Anything else we need to know about? =^[.]~=

[Twistx77]

@koenstr Correct me if I'm wrong,I don't know about a Fresnel Lens but for a normal convergent lense the thicker it is the smaller the focal length is. Water works as part of the lense's thickness.

[koenstr]

but the question is: why is the focal length increasing???

[Frosttty]

Is there any kind of laquer or some other liquid that would harden with nice optical qualities to permanently increase your focal length?

[doug2877]

nice tip

[asmundhagen]

I learned something:-)

Norway

[Shaunt1]

Amazing tool!