THE CAMPAIGN IS NOW OVER. THANKS EVERYONE. We're touched by the amazing response.
We will continue our updates at deciwatt.org where you can also subscribe to our mailing list and follow our development, manufacturing and trial plans.
Listen to Martin's interview here - NPR - Talk of the Nation.
GravityLight is a revolutionary new approach to storing energy and creating illumination. It takes only 3 seconds to lift the weight which powers GravityLight, creating 30 minutes of light on its descent. For free.
Following the initial inspiration of using gravity, and years of perspiration, we have refined the design and it is now ready for production. We need your help to fund the tooling, manufacture and distribution of at least 1000 gravity powered lights. We will gift them to villagers in both Africa and India to use regularly. The follow-up research will tell us how well the lights met their needs, and enable us to refine the design for a more efficient MK2 version. Once we have proved the design, we will be looking to link with NGOs and partners to distribute it as widely as possible. When mass produced the target cost for this light is less than $5.
Did you know that there are currently over 1.5 billion people in the World who have no reliable access to mains electricity? These people rely, instead, on biomass fuels (mostly kerosene) for lighting once the sun goes down.
Lift the weight and let gravity do the rest.
The World Bank estimates that, as a result, 780 million women and children inhale smoke which is equivalent to smoking 2 packets of cigarettes every day. 60% of adult, female lung-cancer victims in developing nations are non-smokers. The fumes also cause eye infections and cataracts, but burning kerosene is also more immediately dangerous: 2.5 million people a year, in India alone, suffer severe burns from overturned kerosene lamps. 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.
The burning of Kerosene for lighting also produces 244 million tonnes of Carbon Dioxide annually.
Our final prototype with ballast bag and bits.
GravityLight vs Solar powered lighting.
A commonly held view is that solar powered lighting is the answer to these problems in the developing world. However a number of conflicting factors combine to complicate matters. 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) sun has shone.
However batteries, panels and lights are expensive, and beyond the reach of people with 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.
LED bulbs do not attract mosquitos like conventional bulbs.
Lower cost self-contained lamps are becoming more widely available, but 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 what you're paying for is the battery, and you will need to replace it every few years. Assuming you can get a new battery... The capacity is often reduced to save money which limits the use time, after which there is no light.
With GravityLight, however, it only takes a few seconds to lift the weight, which creates enough energy for half an an hour of light, whenever it is needed. It has no batteries to run out, replace or dispose of. It is completely clean and green.
Because there are no running costs after the initial low cost purchase, it 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.
Where will you use yours?
Hang it in the shed or make it into a great porch light, you can clip on a hanging basket or anything weighing about 20lbs.
No batteries to drain or replace.
We are Martin Riddiford and Jim Reeves, London based designers who have spent 4 years developing GravityLight as an off-line project. We work for therefore.com, 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.
We’re using a tried and tested manufacturer who has the right expertise to make GravityLight. We have some links to partner organisations in Africa and need to do the same for India. If you're part of an organisation and would like to get involved then please contact us. We are particularly looking for contacts in South America.
Visit our skunk-works website here www.deciwatt.org.
Our movie soundtrack kindly created by Belinda from the bush the tree and me.
Check out John Keane's great Solar For Africa blog.
Can it charge my mobile or ipad?
No. Please visit the deciwatt page for a discussion on this subject.
How long does the GravityLight work for per lift?
The duration and power level/brightness are adjustable between just over 30 minutes and about 18 minutes (depending on what the bag is filled with). The light output on the video is generally at the higher power level.
How much light does GravityLight put out?
GravityLight is designed to be a replacement for a kerosene lamp. GravityLight's output is better than a kerosene lamp.
I can help with your trial, how should I get in touch?
Please email firstname.lastname@example.org with your details and a description of how you may be able to help. We are very keen to hear from all those interested to help with the trial, wherever there is a need. Please bear with us and will be in touch as soon as things calm down a little to discuss / arrange.
BBC Radio4 -Life without electricity in Liberia