A New Class of Lightweight: Gravity Light

To manufacture an affordable lamp, they’d need to understand what people had in abundance other than the sun. The answer: gravity.

When UK-based charity SolarAid came to London’s Therefore Product Design Consultants with an ambitious project in 2009, Jim Reeves was confronted with a global problem he knew little about.

Reeves didn’t know there were roughly 1.3 billion people without access to electricity, and that many of these people were using poisonous, dangerous, inefficient, and relatively expensive makeshift kerosene lamps as their primary light source. SolarAid wanted Reeves and his colleagues to find an alternative.

To conceive of a different light source wasn’t terribly difficult, but the real challenge was creating one that was long-lasting, easy to manufacture and use, and, most importantly, could be purchased for $6 or less.

It was an unusual project for a design consultancy, but Reeves said he’s always been on a search for meaning in what design can do, previously working on a medical injection device designed to reduce needle fear, and for a company that designed prosthetic knee joints that helped people climb stairs. He saw the results first-hand.

“One woman navigated an obstacle course to evaluate her performance, and when she completed it she burst into tears,” he said, adding: “Those products have always gravitated toward me.”

The first step was to find out what was available and what it cost. They looked at solar panels, wind-up devices, and rechargeable batteries, determining that the latter often made up a third of the cost of remote lighting products. To manufacture the product for $6 or less, they’d need to understand what the people they were targeting had in abundance other than the sun, which, obviously, wasn’t accessible at night.

The answer: weight.

Travelling to Africa to test the first version of GravityLight was vital to their understanding of the subtleties and nuances within these remote settings.

GravityLight requires only a sturdy beam for installation and a twelve-kilogram weight—typically a bag of rocks or sand. The weight is lifted off the ground to the device by pulling a bead cord. When the cord is released, the weight gradually descends, powering a gear train that ultimately produces around a tenth of a watt of light—more than that kerosene lamp—for up to thirty minutes. Once the weight reaches the ground, it simply needs to be pulled back up with the cord.

Reeves and his team trialed the product in more than 1,300 off-grid households across twenty-six countries. He said travelling to Africa to test the first version of GravityLight was vital to their understanding of the subtleties and nuances within these remote settings.

He recalled two key insights.

The first was related to the device’s three power settings. “Across the entire trial, whenever the prototype was installed by the volunteer, not one user had adjusted the brightness,” Reeves said, “whether they were reticent to engage with the product or didn’t care to.”

Why this was important was that the component, which Reeves and his team thought would be vital, had several points of failure and added costs. Without it, GravityLight would be simpler, cheaper, and more durable.

The second insight was the result of one of the biggest design obstacles in any market: children.

“There were lots of kids around,” he said, “and we didn’t anticipate them using the bag as a swing. This caused a very high rate of product failure. Parents went out and returned to see the bag on the floor with the gears spinning.”

Photos courtesy of GravityLight

The solution: A warning light that indicated the weight was too great for GravityLight to handle, and, if that failed, a wrap clutch that operates like a slip clutch, allowing the weight to descend freely if too much pressure is applied.

Due to both cost considerations and a desire to boost economic growth in East Africa, they decided to manufacture much of GravityLight in Kenya.

Along with introducing new skills into the local economy, they developed stronger ties with local distribution networks.

Another risk, however, was the potential for mission creep—the propensity for organizations to overextend themselves and widen their mission after receiving a wave of funding instead of focusing on the original goal. GravityLight had to be a self- sustaining business.

“The size of the issue we were attempting to tackle was so enormous that it had to be a financially self-sustaining exercise. For that, you need all of the people working on it to be earning a living. If we relied on charitable contribution, it couldn’t achieve the scale it wanted to achieve,” said Reeves.

They set up a crowdfunding campaign that got massive traction. Roughly 250 organizations reached out to help facilitate trials (they had to narrow it down to fifty-five), and they raised more than US $400,000, making it one of the ten most successful Indiegogo campaigns to that date.

Though Reeves is no longer GravityLight’s technical director, he still works closely with the organization as a technical advisor. The biggest challenges now, not unlike five years ago, he says, are distribution and scale, and how to efficiently demonstrate how to use the product.

He’s optimistic about the convergence of design and non-profit worlds, pointing to the myriad innovation awards and grants that have roots in social funding.

“It feels like a massive groundswell in the breadth that creativity is being used for good,” he said. “It’s very encouraging.”


To find out more about GravityLight, visit gravitylight.org