A system for the multipurpose utilization of solar energy, adapted for use in combination with multi-storied buildings, comprising: a building roof area at a first elevation, adaptedfor storing and exposing water to incident solar radiation; a building roof area at a second elevation, greater than said first elevation, adapted for storing water; a solar collector mounted over the building's roof at said first elevation andincluding airtight means for collecting vapors of the water generated by incident solar radiation; a first electromagnetic generator means mounted on the building roof at the second elevation; a first turbine means operatively connected to the firstgenerator means; duct means, including an elliptically shaped tubular member formed of two half members, where one half member is constructed of a material that will selectively pass solar radiation, and the other half member is constructed of amaterial that will absorb radiation passing through the first half member and heat the contents of the tubular member, connecting the vapor collection means at the first elevation and the first turbine means, whereby vapors collected and passing throughthe said tubular member cause said first turbine to operate; means connected to the first turbine for depositing water condensed in the first turbine on the building roof area at the second elevation; a second electromagnetic generating means; asecond turbine means operatively connected to the second electromagnetic generating means; duct means connecting the second building roof storage area to the second turbine, whereby water from the roof storage area will descend and cause the secondturbine to operate, and means connected to the second turbine for directing water output from the second turbine to the first building roof storage area.
