Gravity lamp could light developing world

London-based designers dream up a gravity powered lamp, which could light the far corners of the developing world using a bag filled with rocks or sand

A UK design duo have dreamed up a gravity-powered lamp which could bring light to remote regions of the developing world.

The GravityLight is powered by the gravity which results from filling a bag with rocks or sand and then slowly lowering it toward the ground.

A series of gears inside the light transfers the weight into energy. It takes three seconds to lift, which creates half-an-hour of light on its descent – and for free after the initial cost of buying the lamp.

Martin Riddiford and Jim Reeves of London design and innovation company, Therefore, have spent four years developing the light, which they say could eventually be sold to villages in isolated developing world countries for as little as $5 (£3.22).

They say there are more than 1.5 billion people in the world who have no reliable access to mains electricity and that GravityLight could be used as an alternative to biomass fuels, the most widely used of which is kerosene, to illuminate rooms and buildings once the sun goes down.

Kerosene is very expensive – sometimes taking up 20% of a household’s budget – as well as producing dangerous fumes.

The project originally arose from a brief from the charity Solar Aid, which aims to eradicate kerosene lamps from Africa by 2020. They say only 14.2% of people in rural sub-Saharan Africa have access to electricity.

An appeal by Riddiford and Reeves on crowdfunding site Indiegogo, to gather funds for the next stage of development attracted pledges of more than £257,000, far exceeding their goal of £35,000.

“The villagers’ investment is returned within three months of being freed from the cost of kerosene,” said Reeves. “From then on, it saves them money.”

The team is currently preparing for production of the GravityLight.