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.

Credentials

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.