Author Topic: [b]GravityLight: the low-cost lamp powered by sand and gravity aiming to light  (Read 287 times)

Offline Esrat

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Why GravityLight?
There are currently over 1.5 billion people in the World who have no reliable access to mains electricity.These people rely, instead, on biomass fuels (mostly kerosene) for lighting once the sun goes down.The World Bank estimates that, as a result, 780 million women and children inhale smoke which is equivalent to smoking 2 packets of cigarettes every day. 60% of adult, female lung-cancer victims in developing nations are non-smokers. The fumes also cause eye infections and cataracts, but burning kerosene is also more immediately dangerous: 2.5 million people a year, in India alone, suffer severe burns from overturned kerosene lamps. Burning Kerosene also comes with a financial burden: kerosene for lighting ALONE can consume 10 to 20% of a household's income. This burden traps people in a permanent state of subsistence living, buying cupfuls of fuel for their daily needs, as and when they can.The burning of Kerosene for lighting also produces 244 million tonnes of Carbon Dioxide annually.

GravityLight vs Solar powered lighting.
When we hear the phrase "alternative energy," chances are our mind goes to windmills and solar panels, or perhaps fields of corn. Few people think of human beings as a renewable energy source. But a new lamp design taps into just that idea.
A commonly held view is that solar powered lighting is the answer to these problems in the developing world. However a number of conflicting factors combine to complicate matters. Solar panels produce electricity only when the sun shines, so the energy needs to be stored in a battery to produce the light when it becomes dark. The amount of energy stored is dependant on the size of the panel, the size of the battery, and how much (if any) sun has shone.

However batteries, panels and lights are expensive, and beyond the reach of people with no savings. Solar lighting projects continue to provide lighting for thousands of people in the developing world, but the spread is slow because the cost is too high for individuals, so they need to be bought and installed by communities instead.

LED bulbs do not attract mosquitos like conventional bulbs.
Lower cost self-contained lamps are becoming more widely available, but batteries are the weak link, because they are expensive and deteriorate through use and over time. Very often, when buying a low cost solar lamp with an inbuilt rechargeable battery, a full third of what we're paying for is the battery, and we will need to replace it every few years. Assuming we can get a new battery. The capacity is often reduced to save money which limits the use time, after which there is no light.

GravityLight is a revolutionary and sustainable new approach to creating energy and generating light from an LED lamp. GravityLight can potentially eliminate the need for kerosene lamps, with huge environmental and economic benefits. It takes only 3 seconds to lift the weight that charges GravityLight, creating 30 minutes of constant light, as the weight drops under the force of gravity. GravityLight has no batteries to run out, replace or dispose of, and has no reliance on the external environment, time of day, season or weather.

This light is a gravity-powered lamp designed for use in developing or third-world nations, as a replacement for kerosene lamps. It uses a bag filled with rocks or earth, attached to a cord, which slowly descends similar to the weight drive in a cuckoo clock.

Concept & development :

It's not a new concept: Wind-up watches and clocks, and even hourglass-style timekeepers, have relied on humans as energy sources for many centuries. A person winds it up or flips it over, and the device has a renewed supply of potential energy with which to operate. Modern inventions like bicycle-powered blenders and kinetic battery chargers draw on energy stored in the human body, too.

Much like these designs, the gravity-powered lamp envisioned by Clay Moulton, a graduate student at Virginia Tech when his lamp won second place at the 2008 Greener Gadgets Design Competition, relies on people for power. In this case, the people don't wind a gear or pedal a bike; instead, they lift a series of weights back to their starting point. The Gravia lamp is powered by the falling motion of those weights, also known as gravity.

This mission began when Deciwatt, founded by inventors Martin Riddiford and Jim Reeves, was challenged by the charity SolarAid to design a new LED lantern for Africa as an alternative to the “ubiquitous and damaging” kerosene lamp. The challenge was undertaken, but as time progressed, the team came up with what they believed was even better than an LED light: a light that is powered solely by the force of gravity. The IndieGoGo campaign of GravityLight was ended on January 15, 2013 with $399,590 funded by 6219 funders. Martin Riddiford and Jim Reeves worked on GravityLight as a side project for four years.


There are no operating costs after the initial purchase of the appliance. A standard GravityLight kit comes with an adjustable lamp and a ballast bag. The light can be turned on by filling the bag with approximately 20 pounds weight and lifting it up to the base of the device; the weight falls over a period of 25 minutes, pulling a strap that spins gears and drives a motor, which continuously powers an LED. This creates enough energy to last 25 minutes whenever it is needed. The lamp can be recharged by solar panel.