Martin Riddiford and Jim Reeves are London based designers who’ve spent 4 years developing the GravityLight as an off-line project. The pair works for, which has over 20 years of experience in designing and developing hand held computing and communication products for a host of pioneers including Psion, Toshiba, NEC, TomTom, Inmarsat, ICO, Sepura, Racal Acoustics, Voller Energy, FreePlay and SolarAid.  Small and handy is the core of their experience.

GravityLight. Click image for the largest view.

GravityLight. Click image for the largest view.

A GravityLight is simple, like some clocks that have weights pulling a chain on a sheave to impart energy to a shaft.  Once the gravity gets the shaft moving the mechanical force can make electricity too.

GravityLight Kit. Click image for the largest view.

GravityLight Kit. Click image for the largest view.

With GravityLight it only takes a few seconds to lift the weight, which creates enough energy for a half hour of LED light, whenever it is needed. It has no batteries to run out, replace or dispose of. It is completely clean and green.

There are no running costs after the initial low cost purchase. Light has the potential to lift people out of poverty, allowing them to use the money they have saved to buy more powerful solar lighting systems in the future.

Out in the real world over 1.5 billion people have no reliable access to grid electricity.  Instead, folks use biomass fuels and petroleum; mostly kerosene in lamps for lighting once the sun goes down.  In India about 2.5 million people a year suffer severe burns from overturned kerosene lamps.

More importantly 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.

Technologists offer that solar powered lighting is the answer to these problems in the developing world. But a number of factors combine to complicate and arrest adoption. 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) the sun has shone.

The major problem is the apparatus of batteries, panels and lights are expensive, and beyond the reach of people with small incomes and 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.  They people have to choose too. Will it be light or education or clean water?

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 the price is the battery, and it will need replaced every few years, assuming there is a new battery available or installable. For now the market has reduced battery capacity to save money, which limits the useable time, after which there is no light.

GravityLight over a Remote Location.  Click image for the largest view.

GravityLight over a Remote Location. Click image for the largest view.

How good is the GravityLight now?  It’s designed to be a replacement for a kerosene lamp, so GravityLight’s output is better than a kerosene lamp. The duration and power level for brightness are adjustable between just over 30 minutes and about 18 minutes with every pull of the line, depending on how much mass is in the gravity weight bag.

Riddiford and Reeves volunteered years of work and have refined the design now ready for production.  They need help to fund the tooling, manufacture and distribution of at least 1000 gravity-powered lights. They will gift them to villagers in both Africa and India for regular use. The follow-up research will tell how well the lights met their needs, and enable the team to refine the design for a more efficient second version.

Once the design is proven they will be looking to link with non governmental organisations and partners to distribute it as widely as possible. When mass-produced the target cost for this light is less than $5, about the cost of 2 gallons of kerosene at the refinery gate.

And yet the light and power system has good potential in the developed world as well.  It would surely be better than a shake to charge LED flashlight. It could be an emergency light and service in a wide array of remote situations.

Gravity Light Installed On Porch and Shed. Click image for the largest view.

Gravity Light Installed On Porch and Shed. Click image for the largest view.

So here’s a shot at giving a bit more this season. Riddiford and Reeves have signed up for support at where your humble writer has already kicked in.  The goal is $55,000.  Almost $275,000 is committed at this writing.  One wonders if they can get to 10x.  One hopes so, I need a few GravityLights myself.

It’s a surefire way to improve life on earth.


5 Comments so far

  1. voxelman on December 30, 2012 3:33 PM

    Just made my contribution as a MEGAWATT on the indiegogo site. Can’t wait for this inspiring product to start making a difference.

  2. voxelman on December 30, 2012 3:34 PM

    Direct link for those interested in contributing:

  3. Richard on January 1, 2013 12:12 PM

    This is an excellent idea, I wonder if a wind-up apparatus like the old clocks with springs would work as well?

  4. voxelman on January 1, 2013 5:00 PM

    The gravitational energy stored in a 10-20 pound weight suspended 5 feet off the floor equates to a lot of winding. This device is very simple and can very its output just by varying the weight. I also suspect that an equivalent spring mechanism would be much larger, heavier and more expensive to manufacture.

  5. Miles Bobrow on January 17, 2013 9:56 AM

    LED flashlights are really great because they do not consume too much electricity.:

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