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Scientists develop a solar-powered lamp designed to light up rural Kenya

Last Updated: Saturday 04 July 2015

with electricity out of reach for many rural areas in Kenya, the uk -based Intermediate Technology Development Group ( itdg ), has developed 'a low cost alternative to a Solar Home System'. In Kenya around 1.5 million households have tried using solar panels, but poor designs and short life batteries have led to many abandoning the systems. Currently 96 per cent of Kenyan householders use kerosene for lighting and 70 per cent supplement this light source with battery-operated torches.

The concept behind the resulting lantern is a simple: during daytime, sunlight falling onto the photo-voltaic panel generates a small electrical voltage. This is used to charge the lanterns' battery so that the lamp can provide light.

The charge control circuit housed within the lantern is the "brain" of the unit. Not only does it ensure that the battery is charged and discharged correctly so that it gives a lifetime of maintenance free service, but it can also "decide" to give the battery an extra top-up charge if the panel has gone without its full quota of sunlight for a few days.

The developers claim that most solar energy systems used today do not effectively regulate the supply of power and as a consequence, the charging circuits are unable to cope with demand. However, in Glowstar, the charge and discharge of the battery is the key to the success of any solar system. With the Glowstar lantern, there is a little bit of circuitry in there which carefully controls the charge and discharge of the battery.

This ensures an extended lifetime to the lantern. In some countries, for example, where there is a lot of sunlight, the lantern can be programmed to charge more quickly and at a higher voltage, whereas in other countries where there is less sunlight, the lantern can be programmed to charge over a longer period of time.'

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