The Solar Pebble is a powerful solar lamp which its designers Plus Minus Design are targeting for use in rural Africa and also for the camping market in the UK.
The Leeds-based company highlights the reliance on kerosene lamps in sub-Saharan Africa, which are harmful to health and the environment. The Solar Pebble can provide clean lighting to allow families in developing countries carry on their activities into the evening.
A small but efficient solar panel sits at the heart of the Solar Pebble that charges a 5V battery to power three banks of three LEDs. One hour charge time is enough to power one bank of three LEDs for one-and-a-half hours. There is also a 6V output socket for charging mobile phones and other devices.
To be fit for use in tough and hot outdoor environments, the Solar Pebble clearly needs to be robust in design and materials. Adam Robinson, managing director of Plus Minus Design, told PRW the design combines ruggedness and functionality.
The curves of the housing help towards toughness but also perform another important function. The curved surface concentrates sunlight on the solar panel as it enters the lamp and also allows a wider diffraction of light as it exits from the LEDs.
Polycarbonate was chosen for the outer housing, again for two purposes: strength and optical clarity. As well as demanding heat and drop tolerances, another material requirement was UV stability.
The difficult working environment of rural Africa meant the designers ensured the lamp would be rain-proof and dust-proof. To achieve this they designed an interior housing in rubber which also acts as a seal.
Robinson described the shape as similar to ravioli, with the lamp’s electronics in the cavity and the rubber extending at the edges to form the seal.
The company is working closely with manufacturers to have the lamp ready for launch in June. This is intended to take place in Uganda and then it plans to launch in the UK a month or so afterwards.