Solar Alternative Energy

archimedes_death_ray

My STEMulate Learning workshop participants asked how I got started with alternative energy designs, which I attribute to the stress of the oil crisis during the 1970’s when I was a youth and reading an account of Archimedes’ “Death Ray” design that supposedly set ships afire from the shore using reflected sunlight.

Telescope

While I originally tried to improve the power output of my small solar cells using light reflected at an angle using a simple mirror, I received a telescope for Christmas and was able to use the mirrors and lenses to focus sunlight out through the port for the removable eyepiece where I located the solar cell.

WARNING: DO NOT USE A TELESCOPE TO VIEW THE SUN DIRECTLY OR YOU CAN BE BLINDED!

After finding success with this cumbersome configuration, I began preparation for school Science Fair after receiving a non-functional overhead projector with damaged electronic wiring.

overhead-projector

I first tested the elevated magnifying lens to concentrate sunlight onto the solar cell, capturing data on the output voltage both with and without the lens. Together with designs for alcohol production from biomaterial I was able to build using designs from The FoxFire Book, and a small vertical-axis wind turbine built from an old Coca-Cola can, a coat hanger, and several small magnets. The three designs were integrated into a project that reached the final round of the Fair at Scottsdale Middle School and then the Phoenix area, but the crudity of my models and lack of project graphics did not advance this to the State level competition.

 fresnel B  fresnel A

After wards, I considered the plastic fresnel lens from the overhead projector (above, left), which was much lighter than its heavier glass magnifying lens (above, right), and this worked much more effectively both due to the reduced weight of the apparatus as well as the larger solar area concentrated onto the photo-voltaic cell.

LighthouseLensHawaiiFresnel lenses have been used for many purposes, such as this photo of a lighthouse lens from my recent visit to Hawai’i. They allow a lens to operate without the full mass of glass that would be needed for a similar standard lens.

SolarArray

Because the Science Fair in Phoenix attracted scientists from different fields, one researcher from NASA contacted me several times over the years that followed as they built a version of this original design for use in space. By using transparent silicone, lightweight stretched arrays could be lifted up with a reduced total launch weight compared to traditional photocell panels.

Deep_Space_1_Launch

I understand they have since launched the design in a much more mature form on the DeepSpace-1 test vehicle that went up in the late 1990’s, together with Gallium Arsenide photocells.

I have since applied various solar, biofuel, and vertical-axis wind turbine (VAWT) designs in many later studies both for my own research as well as to assist my student’s designs as well. I have occasionally spoken about this first alternative energy design as it applies in my later interest and research, noting that the environment of the 1970’s and early 1980’s encouraged a lot of new ideas which drifted away into nothing as oil prices fell – until the 2000’s and more recent times as rising oil prices have made alternatives more attractive again.

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