Solar water distillation - Zambian perspective

Solar water distillation systems produce clean drinking water from polluted water and are suitable for remote regions. A simple solar still comprises a shallow depression in the ground to contain the polluted water and a transparent cover placed over the depression. The system uses the greenhouse effect to evaporate the water by incoming solar radiation and the resulting condensation forming on the inner surface of the cover is collected. The condensed water is free of any chemical and biological contamination. Although solar water distillation is effective and solar energy is clean, safe and viable in many countries, it has not found wide-spread use due to high capital investment. In Zambia the problem has been compounded by lack of awareness about renewable technologies, inadequate adaptive research on solar distillation technology to the Zambian situation and lack of demonstration projects. For the people in rural areas who boil their drinking water, firewood is the only source of energy. In view of the current concerns of environmental pollution, deforestation and health hazards caused by the burning of firewood, and because few rural Zambian communities are connected to the national electricity grid, solar water distillation has a potential for wide-spread use.