“Gravity Powered” Lights (and How to Make Them More Powerful)

gravity powered lights

The GravityLight uses a sack of sand or stones to gradually pull a piece of rope through a dynamo mechanism which generates electricity to power an LED. It is a cheaper and more sustainable option than a solar powered light, which requires not only a solar panel but also a battery. The product is aimed at the developing world and its makers raised 400,000 dollars at indiegogo.

The technology could be further improved by including pulley mechanisms that were used to operate human powered cranes and lifting devices in pre-industrial times. This would allow a person to lift heavier weights and thus power more powerful lights.

To be precise, the light is not powered by gravity. It is muscle-powered, while gravity stores the energy and fulfills the role of a battery. Hat tip to Bernd Vleugels.

Low-tech Bulbs for Dark Slums

Watch the video. Thank you, Joe Blogs and Lalon.

Environmental Impacts of Light-Emitting Diodes (LEDs)

leds environmental impact

Light-emitting diodes (LEDs) are advertised as environmentally friendly because they are energy efficient and mercury free. However, the material content of the LEDs, which generally include group III-V semiconductors, presents its own set of potential environmental impacts. The rapid growth in the LED industry implies that, ultimately, LEDs will contribute to the solid waste stream, and could impact resource availability, human health, and ecosystems in much the same way as generic electronic waste (e-waste) from computers and cell phones has generated concern in recent years.

Potential Environmental Impacts of Light-Emitting Diodes (LEDs): Metallic Resources, Toxicity, and Hazardous Waste Classification (pdf).

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Digital Billboards

“The growing number of digital billboards on U.S. roads and highways consume large amounts of energy and are creating a wide variety of electronic waste, according to a new report (pdf). The new study says the typical digital billboard consumes about 30 times as much energy as the average American household.”

Energy use led billboards“The digital billboards use more efficient LED (Light Emitting Diode) lighting than traditional signs, but deploy so many of the LED bulbs on each billboard that energy use is high; traditional billboards use just one or two large bulbs to illuminate signs. In addition, digital billboards are illuminated day and night, and require cooling systems that use more energy.”

Source: Yale Environment 360.

Previously: Viva Las Vegas – LEDs and the energy efficiency paradox.