Inventors’ Pack Our Mission
Our mission is to eliminate 1 in 7 people do not have access to There are many good reasons to Polluting kerosene lamps and their electricity; in sub-Saharan Africa it is as eliminate kerosene lamps: Collectively, kerosene lamps cause 3% damaging effects. high as 2 in 3. of the world’s CO2 emissions. They are a Dangerous significant source of black carbon, with Without electricity, the majority of families Their fumes cause coughing, eye irritation even more intense local warming impact. use kerosene lamps to light their homes. and respiratory diseases. Unprotected flames and over-turned lamps can cause An ongoing expense A typical kerosene lamp is made from an severe burns. The cost of kerosene is a poverty trap. empty bottle or tin can with a wick in the Amongst the poorest households, it middle, filled with fuel and lit. Unsupervised containers of kerosene can consumes up to 20% of their income. The lead to unintentional ingestion, currently amount of light families can have - for the leading cause of child poisoning in the reading, cooking and socialising - each developing world. evening is limited by what they can afford. Our Approach
Using good design to tackle poverty Sustainable and scalable Creating livelihoods, locally Collaborative We are committed to creating solutions If we gave away GravityLights to the over As well as enabling people to save money Building trusted local partnerships will be informed and guided by the needs and 1.1 billion people that don’t have access to by switching from kerosene lamps to a integral to our work. From manufacturing feedback of low income households electricity, we would need to raise a lot of GravityLight, our plan is to partner with to assembly, distribution and impact living in energy poverty. It’s not enough money! Give-aways also risk undermining local organisations to create jobs and help measurement, we will be working with a to create affordable solutions, to have a local livelihoods of those selling lighting people earn an income through distributing number of organisations, benefiting from scalable impact these need to be reliable, solutions. GravityLights. their experience and reach to maximize robust and attractive too. This is why focus Instead, by creating a product that our impact. groups, trials and pilots are central to both people value and are willing to pay for, our product development and route to GravityLight will be able to reach far market planning. more people, more quickly, without it’s fate being solely reliant on continuous fundraising. Our Solution
GravityLight has been designed Money saving: with no running costs it as a safe, clean and affordable pays for itself within 4 months of switching alternative to kerosene lamps. from kerosene lamps.
Powered by the lift of a weight, Safe and clean: with no fumes nor fire. GravityLight offers instant, limitless light, whatever the Instant: no charging needed weather outside. No sun needed: a year-round solution. GravityLight has multiple benefits, including: Limitless: GravityLight can be used over and over again, not limited by battery capacity or lifespan. How GravityLight Works
GravityLight transforms the pull of GravityLight is installed at around 6ft/ This sprocket drives a gear train at After 20 minutes, the weight will slowly gravity into electricity. 1.8m from the ground. The bag is filled increasingly higher speed and lower torque reach the ground and the gears and with 12kg of weight – such as rocks or (force), driving a DC generator – a motor run motor will stop turning. If this happens, The potential energy of a raised weight is sand. backwards - at thousands of rotations per the light will turn off. For more light, turned into kinetic energy as the weight minute. simply lift the weight again, or for descends and turns a gear traIn. The orange cord is pulled to lift the weight continuous light, raise the weight back up and, as the weight gradually descends In this way, GravityLight generates just before it touches the ground. The gears power a generator, turning (about 1mm per second), it turns a drive under a deciwatt (0.1 watt) of electricity, mechanical energy into electricity that sprocket at high torque (force) and low which we use to power LEDs to create light. Watch a video of GravityLight’ geartrain in powers an LED (light emitting diode). speed. action and explaination of how it works in Destin Sandin’s Smarter Everyday episode. How GravityLight Works: FAQs
Why hasn’t a GravityLight been How do the gears withstand the The further through the drive train you What stops the bag from falling made before? 12kg weight? go, the fewer teeth are needed to engage fast to the floor? Using the force of gravity and kinetic energy The side of the GravityLight closest to because the torque gets lighter and The LEDs. The fastest gear is running at to create electricity is not a new idea. the weight (where forces are larger) uses lighter as the speed runs faster – with the a high speed but such low torque (force) What is new – and continually improving – is internal gearing. This means one gear generator running at 1600 rotations per that even a small bit of resistance can the efficiency of LED technology in turning running in the inner diameter of another minute. reduce the speed of the gear. electricity into light. The 0.1 watt produced gear, to ensure multiple teeth of the gear by GravityLight equals 16 lumens of light – are engaged at a time. Once the generator turns up to a certain over 5 times brighter than a kerosene lamp. speed and the voltage limit of the LED is LEDs are currently at about 30% efficiency. This is important for transmitting the reached, the LED will not let it turn any As they continue to improve, the amount force of the weight over multiple teeth faster. This means the weight falls at a of light produced by GravityLight will also thus decreasing the contact stress and slow, constant speed. increase. increasing the life of the gear. Evolution of GravityLight: Concept Testing
Product designers, Martin They set out exploring solutions that could With the incredible, worldwide support The objectives of the trial were to: Riddiford and Jim Reeves, first avoid the high costs and limited life span of our first crowdfunding campaign, heard about the challenge of of batteries and that use an energy source this concept was developed further. We - prove the concept: Would people use a kerosene lamps and scale of the as ubiquitous and accessible as weight manufactured the first small batch of GravityLight instead of a kerosene lamp? issues through UK charity, Solar and gravity. GravityLights to be tested in a range of Aid, in 2009. different environments. - test demand: Would people buy one? To prove the principle, Martin and Jim developed several prototypes, from a - gather feedback: What did people like bicycle wheel and dumbbells, to creating about GravityLight and what needed Selective Laser Sintering (SLS) gears improving? connected to a motor and LEDs. GL01 GL02
Our production prototype, GL01, Accessibility: Some people struggled to lift Our revised design, GL02, Brighter: GL02 is 50% more efficient than was a critical milestone in the the 12kg weight from the ground up to the incorporates this feedback and GL01 through material selection and re- development of GravityLight. It full height. two further years of development design of the gear train. This additional enabled us to test our technology to optimise its efficiency, reliability power has been used to make GL02 on a large scale and determine the Product failure and misuse: Several and lifespan. brighter at a longer duration than GL01. viability of the concept. children used GravityLight as a swing, Longer lifespan: Extensive accelerated overloading and breaking the gears. Improvements with GL02 include: life testing has helped us identify and The power setting, choosing between 90% of GL01 trialists reported that they address causes of product failures. The brightness and duration, was rarely used would use GravityLight instead of a More accessible: Introduction of a pulley geartrain is 9 times stronger, GL02 comes kerosene lamp. What was even more useful but also occasionally caused failures. system to lift the weight, it feels like lifting a with a 1 year warranty and our test rigs was finding out why some people would not: 2kg weight rather than 12kg. in the UK have lasted over 3 years of Lifespan: This was as short as 3 months continuous use. for some units vs a 1 year minimum target. SatLights
Each GravityLight comes with 2 A SatLight consist of two plastic mouldings, SatLights, ancillary lights that are a Printed Circuit Board (PCB) and a surface powered by GravityLight. SatLights mount LED. The PCB (a development since transform GravityLight from a GL01 SatLights) enables the use of stereo single, ambient light into multi- cables and the ability to switch each light on user, home lighting. and off as needed. By twisting the upper and lower plastic The first SatLight plugs into the GravityLight, mouldings, users can change the light settings with subsequent lights in the chain plugging and decide when and where they want light. into each other. With a 5 metre stereo cable, This feature also adjusts the brightness of the these lights can be hung around a room, for light;users can choose a single, bright task light both ambient and task lighting. to work by or three lights that share the 0.1W power between them. Value Added Engineering
Designing a solution that is as Our aim is for GravityLight to scale affordable as possible, for families through market forces, which means that living on the equivalent of just a GravityLight needs to be an aspirational few US Dollars per day, can risk product with elegant design for people to focusing solely on cost. want to buy one and proudly use it in their home. Such a value engineering approach may help reduce costs to a Even more importantly, people with minimum, but at the expense limited incomes can’t afford to buy cheap, of performance, durability and unreliable products. They need confidence – importantly for our ability to that purchasing a GravityLight will be a sustainably scale - attractive good investment, with a sufficient lifespan design that people aspire to have. to pay for itself and generate savings by switching from kerosene. Value Added Engineering
So how do you design a product that does in the long term with a lower bill of materials. Rigorous testing procedures are also a vital Our Accelerated Life Testing rig meant that we not compromise quality and durability, but is component of a successful value added could monitor GravityLight’s performance over also affordable for low income households? A large amount of the time that we spent in approach. Understanding and improving time, taking readings every few days to monitor The answer comes in adopting a value added R&D was dedicated towards testing the same GravityLight’s durability and lifespan was power output. If an issue was identified, the rig engineering approach. At its root, value added components using a plethora of polymers paramount. To We did this by creating a would be dismantled and components tested engineering is a commitment towards spending and metal alloys. A narrower approach would custom-made Accelerate Life Testing rig, that until the root cause found and addressed. longer on finding solutions. Adopting a value usually be employed for western market runs GravityLights continually. added engineering approach generally requires products, however with GravityLight, small Although this is a long, iterative process that a higher R&D budget; it interrogates each degrees of difference matter. We interrogated Families using kerosene lamps typically use needs to be re-set with each change, in this individual aspect of the overall design with a large array of materials to arrive at the final them for four hours a day. This rig enabled us way we were able to improve GravityLight’s rigor and recognises that the time cost spent configuration – one that was low in cost, but to condense one year of use into two months efficiency by 50% and lifespan from 3 months on the intensified level of focus will be justified uncompromising of quality. of non-stop running. to 3 years. Martin Riddiford (Co-Inventor)
Product design is a very broad and varied Product design can come with many job and although the variety of products challenges even after you have developed and ideas that we work on are very broad, a solution, and GravityLight was no there is one running theme which tie all different. One of the main things I have these projects together, and it is integral to learnt through the development of designing successful new products; being GravityLight was the need to assess the able to succinctly state ‘the problem’. With risks of each decision, to be able to assess GravityLight, SolarAid provided us with a what could go wrong. problem – kerosene lighting. Coming from a designer background I Being able to work with the potential of often have to go in with an optimistic hat human power was the perfect solution – I on, this was not the case with GravityLight, realised that through the use of gravity and it required us to be positive but also weight you could create an energy store, assess all angles and risks. This has made with no running costs. After some quick GravityLight such a unique project to calculations I reckoned we could get about invent and develop. a deciwatt of power, which would provide more light than a kerosene lamp - this led to It can be very easy to design a variety of our first bicycle wheel prototype. interesting products for the West, but when you step back you can realise there The development of GL02 was a major step is little long term worth, they quickly forward. One ‘eureka moment’ was the become just another gadget. development of the SatLight, we developed GravityLight to be able to power other GravityLight is different. It has been things, other LEDs. It would provide less designed with a focus on a fundamental power to the main light but seemingly problem, affecting millions of people, that create brighter light through the spread and needs real solutions – and that’s what separate pools of light. This was exciting makes it so unique. for a number of reasons, as not only did it spread the light, it solved a problem that off- Thank you for your support - to help make grid families have, the lack of wired home, it GravityLight a reality and start to realize enabled the sophistication of being able to it’s potential for huge positive impact. turn light on and off with a switch. Jim Reeves (Co-Inventor)
From initial analysis of the problem, through This can be one of the hardest parts: multiple concepts and numerous iterations, being critical of your own thinking when a all the way to the creation of a supply chain particular route showed such compelling network, delivery, and international product potential. GravityLight is made up of a launch, GravityLight has been a more rich, lot a functional bits. Each needs to be varied and demanding journey than I ever developed and delivered at minimum cost, could have imagined. and each needs to work, time and time again. The successful delivery of viable and reliable products that truly answer the We set ourselves some quite unreasonable needs, expectations, and aspirations of challenges when we set out to make users takes a lot of key ingredients. While GravityLight a reality, and we continue the essence of the idea is the critical start to work toward meeting them. The point, the approach to developing solutions requirement for rigorous and thorough is what makes the difference between engineering development and verification an interesting ‘almost’ and a real answer. may not be self-evident - the concept Product development also requires a lot of is simple after all. Making the product resource and our challenge has been wider deliver, delight and surpass expectations, than merely developing and delivering a however, has taken a sharp focus on the truly unique and innovative product, it has smallest of details. Small aspects can be also been about how to build the resource, transformative, both for better and for support and funding to do so. worse.
As a designer and engineer I am driven I consider myself very lucky to have had by a desire to solve the problems I see. the opportunity to design and develop a Sometimes just for their own sake - because product with such valid aspirations. One of they are interesting, or hard. To do this, the key measures of whether a product is we make continual evaluations of the interesting to me is how much it ‘deserves’ effectiveness and potential of different to exist. Is it really needed? For me, development options and paths. A GravityLight truly fulfils this requirement. dogged focus and determination to reach a complete and working solution is not Thank you for your support on this enough. You also need to know when to journey. We look forward to sharing change tack and explore other options; to GravityLight’s progress and impact with recognise when it isn’t working. you. @gravitylight www.gravitylight.org [email protected]