Using gravity to light up Sub-Saharan Africa

Using gravity to light up Sub-Saharan Africa

A UK-based organization is using gravity to offer a safe and efficient alternative to toxic kerosene lamps in the developing world. We tell you how it works.

Text: S Shantha Photo:

Six years ago, Job Mwancha set out to meet villagers in Greater Nairobi region. He came across families straining to buy kerosene lamps, which was their only source of light since they were living off-grid and lacked access to electricity.

“Given the villagers’ monthly earnings, using kerosene every day proved to be an expensive affair,” explains Mwancha, a regional sales manager for GravityLight Foundation’s Greater Nairobi region. Unable to bear the expense, the villagers used kerosene sparingly and only for the most important chores of the day. So, cooking and other domestic chores were prioritised over children’s education. But Mwancha knew this wasn’t sustainable in the long run.

Kerosene-fuelled lamps have extensive health and environmental drawbacks. The World Bank estimates that nearly 780 million women and children use kerosene lamps, and breathing the carbon-heavy fumes is equivalent to smoking 170 cigarettes per year. Researchers say seven to nine per cent of kerosene burned is converted to black carbon – a high emission factor that causes alarm. But then a unique solution to the problem took shape.

GravityLight is an invention, as the name suggests, that uses the power of gravity to generate light. Created by industrial designers Jim Reeves and Martin Riddiford, the gadget is an affordable, reliable and safe alternative to kerosene. Why safer? Because this device requires only the lift of a weight - a bag weighing approximately 12kg (25 pounds) filled with rocks or earth - to power one main light and two 'sat' lights.

GravityLight has played a crucial role in providing a sustainable source of light to Kenyans who are living off-grid. Although 90 per cent of public facilities in Kenya have access to electricity, over 50 per cent of the households are far from being connected to the grid. And the invention’s simple mechanism makes it all the more popular among users. 

Using gravity to light up Sub-Saharan Africa6
GravityLight is created by industrial designers
Martin Riddiford (left) and Jim Reeves.


The mechanics and popularity

The pineapple-sized lantern works on basic principles, like the one in old grandfather clocks. The lantern is attached to a belt that loops over its internal gears, connected to a generator. It takes only a few seconds for someone to pull the weight of 12kgs to the device’s suspended height of about six feet above the floor. The device then produces light for over 20 minutes. In this time, the device slowly uncoils itself as it descends. The weight has to be re-lifted after 20 - 30 minutes but the fact that it makes for a green, battery-free stream of light makes it worth the effort.

Douglas Mramba agrees. “GravityLight has given us a source of clean energy that is stress, danger and cost free,” says Mramba, a small scale coconut and mango farmer from Kisiwa Tanga village in Malindi, Kilfi County, who has been using the device for eight months. He says the light has made life bearable for him and his five children. Mramba is so impressed with the gravity-powered light that he admits he is not in a hurry to sign up for the rural electrification programme that is expected to start in his sub-county soon.

“I have even forgotten the price of kerosene,” he adds.

Halima Mumba’s family, in the Mombasa region of Kenya, is singing the same tune. The family grows vegetables for its own subsistence and had been struggling to stay afloat with the rising expenditure on kerosene. But after the Foundation’s Managing Director Caroline Angus visited the Mumbas and introduced them to GravityLight in June last year, they completely stopped using kerosene lamps. This change has also benefitted her neighbours - who now send their children to Mumba’s home to complete their homework.

Along with lighting up the houses here, GravityLight has also succeeded in generating jobs for the locals. Regional sales manager for the Coast Region, James Akali said that the organization has been recruiting agents from the local groups to help in their business. “That way they also earn a small stipend as they help us spread the word about the light.”

Using gravity to light up Sub-Saharan Africa2

Using gravity to light up Sub-Saharan Africa3

The journey so far

It started as a small venture when Jim Reeves and Martin Riddiford were asked by the charity, Solar Aid, to develop a viable alternative to kerosene lanterns for under USD 10. A successful fundraising campaign, in 2013, raised the money to tool, manufacture and distribute the first 1,000 lights. The venture conducted field trials and research in 26 countries through 55 partner organizations, culminating in a product launch in Kenya last year. Their teams have visited several villages in the regions of Africa, Asia, Latin America and the Middle East where most of 1.3bn people are off-the-grid.

Going forward, the Foundation aims to make the device available to people across geographies. The force is definitely on its side. 

Using gravity to light up Sub-Saharan Africa5

Leave a comment

Load more comments

Related articles