Solar power feeds twelve

A low-cost solar cooker built largely of mud and straw (adobe) has been successfully tested in Tanzania. Costing about US$12, which is one-fifth the cost of other solar cookers, it is considered to be the first truly affordable, yet robust family-sized cooker. The cooker is built on-site with a minimum of tools, skills or special materials. It is of the 'box-cooker' type and uses the 'greenhouse effect' to trap solar energy inside a glazed, insulated box. It consists of a shallow one metre-square hole in the ground, insulated with straw or dried grass, lined with adobe and covered by glass or clear plastic. Above the cooker is placed a one metre-square aluminized plastic reflector with guy ropes for support and adjustment. Access to the oven is through an insulated door made of layers of corrugated card stuck together with glue and sewn inside a piece of woollen blanket. On the oven bottom there is a black-painted steel or aluminium base plate which rests on a 5cm thick adobe slab. The cooker has been tested in two rural regions of Tanzania where fuelwood is in short supply and has proved able to cook staple dishes such as rice, beans and ugali. On clear days the cooker is able to bring a four-litre pot (25cm diameter by 15cm high) of water up to cooking temperature (80°C) in 7080 minutes. The cooker is able to provide cooked food for up to 12 people at around midday and dusk and food left inside keeps hot well after dark. Solar cooking techniques are different from traditional cooking methods: for instance, in conventional cooking ugali has to be stirred regularly but this is not necessary with the solar cooker. Training is needed before the solar cooker can be used satisfactorily and a simple solar cookbook is now being written with the help of villagers. Sunseed Desert Technology Sunseed trust Eastside Huntingdon Cambridge, UKA low-cost solar cooker built largely of mud and straw (adobe) has been successfully tested in Tanzania. Costing aboutUS$12, which is one-fifth the cost of other solar cookers, it is considered to be the first truly affordable, yet robust..