Solar pond

US4091800A · kind A · utility

Assignee

• The United States of America as represented by the Administrator of the National Aeronautics and Space Administration · US

Inventors

• James C. Administrator of the National Aeronautics and Space Fletcher
• Charles G. Miller · Branford, US
• James B. Stephens · La Cañada Flintridge, US

Key dates

• Filing date: Jun 30, 1977
• Grant date: May 30, 1978
• Expiry date: Jun 30, 1997

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02E10/44
• WIPO field: Thermal processes and apparatus
• WIPO sector: Mechanical engineering

Abstract

Use of shallow pools of liquid to collect low-temperature solar generated thermal energy on a large scale for commercial use becomes economically feasible when use is made of efficient means to keep the liquid in the pond clean, prevent evaporation, prevent air convection and prevent convective circulation of the liquid. Narrow elongated trenches, grouped together over a wide area, can be formed by bulldozer type equipment. Each trench is lined with a heat-absorbing black liner. The liquid in the bottom of each trench, used to absorb the solar energy, may be a brine solution or plain water, depending on the means used to remove the thermal energy from the pond. The heat-absorbing liquid is kept separate from the thermal energy removing fluid by means such as clear polyethylene material. The covering for the pond may be a fluid or solid. If the covering is a fluid, fire fighting foam, continuously generated, or siloons are used to keep the surface covering clean and insulated. If the thermal energy removing fluid is a gas, a fluid insulation layer contained in a flat polyethylene tubing is used to cover the pond. The side of the tube directed towards the sun is treated to block out …