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Renewable energy developments
A low-cost technique for converting radios, cassette players, torches and small lanterns to solar-power is being pioneered in Africa by Graham Knight of BioDesign.
BioDesign has made the conversion of small appliances to solar power cheap and simple. It's strategy is to supply all the raw materials, unframed amorphous silicon (a-Si) solar plates, diodes and low-cost rechargeable Nickel Cadmium (NiCd) batteries, that are necessary for the local assembly of 'D.I.Y' solar systems in developing countries.
This mail order approach to solar power revolves around local people assembling the equipment by following simple instructions that are enclosed in the kits.
Car batteries and specially adapted `solar' lead acid batteries are typically used to store solar power, yet for the small amounts of power required for the majority of domestic purposes NiCd batteries are more affordable and convenient.
These batteries work best if they are allowed to go completely flat before recharging. If used in such a way they can provide small yet constant amounts of maintenance free power for 2.5 years or more. The characteristics of these batteries enable lights to be used every night, until the batteries run down, and the batteries recharged every day
A-Si solar plates are preferred to higher efficiency crystalline panels because their initial cost is lower. They do, however, need to be protected from water damage and accidental breakage because a-Si is just a thin laminated layer on glass. As it is crucial that the solar plates do not get damp, BioDesign promote simple yet effective methods to weather proof the final DIY panel and advise users not leave them out in bad weather.
This type of solar plate can be easily cut to the required size using a normal glass cutter.
One square foot of high quality a-Si plate provides approximately 4 watts of power under full sunlight.
The low-cost photovoltaic solar technique developed by BioDesign allows radios and even cassettes to be powered directly from sunlight without using rechargeable batteries. In this way a small 6v radio can become solar powered from as little as $5 (using a 1 watt a-Si panel).
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