Lighting homes (and the developing world) with gravity

In today’s global economy and marketplace, what can $6 buy you?

Maybe a McDonald’s Big Mac, two tall lattes from Starbucks and about six songs from iTunes with pennies to spare, to name a few.

But what if your $6 could buy a light — and power — source that is more reliable than solar and other renewable energy sources on a household scale and provides illumination as bright as the light from a kerosene lamp?

Faced with the challenge of bringing a cheap yet sustainable energy alternative to widely-used but hazardous kerosene and costly solar panels to light up off-grid communities in the developing world, innovators from Deciwatt, a London-based design consultancy firm, created GravityLight — a light and energy source powered by gravity.

“[The idea came] in considering the problem at the outset … the realization that a bag filled with stones could replace expensive alternatives as an energy store [and source],” we learned from Jim Reeves, who came up with the idea of GravityLight along with product design consultant and co-inventor Martin Riddiford, inspired by the idea of “doing more with less energy.”

The innovation works just by using a specific weight (usually 10 kg of sand, stones or water), a low-cost generator, a LED light and the effort of lifting the weight for the whole technology to work. GravityLight takes only 3 seconds — the amount of time for an individual to lift the 10 kg bag — for 30 minutes of bright light.

Reeves further explained in a TEDxWarwick talk that the innovation also came about from environmental and health concerns. Kerosene lamps give off harmful gases, threatening households’ safety, the environment and people’s health. The World Bank estimates that in Africa, 780 million women and children breathe in fumes from kerosene lamps equivalent to smoking 40 cigarettes a day.

“If you light your house with kerosene, up to 20 percent of your household income can be consumed in paying for it. If a fifth of your income is being spent on kerosene, how do you save up for the alternative, that’s why it’s a poverty trap,” he said. “Two billion people living in poverty and poverty shortens life and causes suffering.”

Future plans

In coming up with the innovation, however, Deciwatt faced some huge challenges, including funding, skepticism from the developing world as well as the dilemma to reconcile cost with the technology without compromising performance.

“In truth, at first it didn’t go well. But it’s an iterative process. You see what doesn’t work, you move on. You see what doesn’t work, and you improve upon it,” Reeves said, adding that back in 2012, the technology was in danger of being shelved due to lack of funding during the trial phase in Africa and Asia.

But he shared that the “interest and global generosity towards GravityLight massively exceeded expectations” — raising $399,590 from the original target of just $55,000 — and that enabled the whole team to improve the design and get closer to making it more accessible to everyone.

Deciwatt is currently planning to mass produce the technology and make it commercially available by next year while making sure costs will be committed to the $6 benchmark.

Other plans include exploring GravityLight’s adaptability and capacity to act as a battery, scale up the principle for other applications and innovations, or establishing how small amounts of constant power can be utilized to provide low-cost Internet access from remote locations. This is on top of the continuing operations to introduce SatLight, a peripheral light contraption that can be used to wire six additional LED lights to a household.

Reeves said there will be opportunities for “local people living in rural off-grid communities to become distributors.”

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