Summary
The future wordwide depletion of petroleum deposits constitutes nowadays a serious concern for all mankind. Consequently, this feared demise of ease and inexpensive oil, has spurred interest on the search for others energy alternatives. A sarvey carried out within urban households and hotels in Manaus showed that a part of its energy consumption is used to heat water for human confort. Shifting to solar energy from the present system of water heating — which is based on electrify, butane gas and fueloil — would bring about substantial savings in fossil fuels. Existing local experiments have shown this substitution to be satisfatory.