solar

How-To: Fold-Up Fresnel Reflector

How-To: Fold-Up Fresnel Reflector

Uwe Oehler has written a simple program that prints out fold-up paper templates for the conic sections that make up the reflective surface of a Fresnel mirror. Cut the templates out of cardboard, cover the cardboard with aluminum tape, fold up the sections, and apply them to a flat backing. Even the relatively simple, five ring, 59% coverage reflector shown in the video will burn holes in construction paper under modest sunlight.

Solar Heater From Can Lids and Woven Plants

Solar Heater From Can Lids and Woven Plants

An interesting experiment from students in a course at Humboldt State University called Appropriate Technology Engineering 305. The parabolic form is essentially a large, shallow basket woven with fibers of locally-gathered Himalaya blackberry, which the students identify as an invasive species. In good weather, their dish could boil a jar of water in about two hours. I always like to see the clever thinking that can result from radical design constraints. [via No Tech Magazine]

3V of Renewable Power from 93 Million Miles Away!

To date, most of our Weekend Projects, by design, have been battery-powered, save our inaugural project, the USB Webcam Microscope, which uses a USB cable (5V) as its power supply. In our Floating Glow Display project, the battery clip even provided a sculptural element, doubling as the base for our display. Our latest project still uses batteries, only now, you’ll never need to swap them out for fresh power! The Solar TV Remote project will teach you first and foremost how to fabricate a solar power pack capable of supplying two rechargeable AA batteries with 3V of renewable energy goodness!

Solar concentrator from old satellite dish

Solar concentrator from old satellite dish

Made from an ordinary fiberglass satellite dish, it is covered in about 5800 3/8″ (~1cm) mirror tiles. When properly aligned, it can generate a spot the size of a dime with an intensity of 5000 times normal daylight. This intensity of light is more than enough to melt steel, vaporize aluminum, boil concrete, turn dirt into lava, and obliterate any organic material in an instant. It stands at 5’9″ and is 42″ across.