zonnetorens

Zonnetorens, literally “sun towers” in Dutch, is a term used to describe tall structures designed to harness solar energy through central-receiver solar thermal technology. In this approach a field of mirrors, or heliostats, tracks the sun and concentrates sunlight onto a receiver mounted on the top of the tower. The captured heat is transferred to a working fluid, which drives a turbine to produce electricity or stored for later use.

History and development of zonnetorens began with experimental and pilot plants in the late 20th century, advancing through various national programs. Early demonstrations in the United States paved the way for commercial-scale installations in Europe and other regions. A key advancement has been the use of thermal storage, often with molten salt, to extend power generation beyond daylight hours and improve grid reliability.

Design and operation typically involve a large heliostat field surrounding a tall central tower. The receiver at the summit absorbs concentrated solar energy, transferring heat to a heat-transfer fluid. This fluid can drive a steam turbine to generate electricity or be stored for later use. Storage enables dispatchable output and can improve capacity factors in sunny locations.

Applications and variants of zonnetorens are primarily in utility-scale solar-thermal plants. In architectural discourse, the term may also be used to describe building concepts where a central sun-collection tower is integrated into daylighting or climate-control strategies, sometimes with reflective elements arranged to direct sunlight into interior spaces.

Advantages include low operating emissions and potential energy storage; challenges involve high upfront costs, large land requirements, and environmental considerations such as impacts on wildlife and local ecosystems. See also solar thermal energy, heliostats, central-receiver systems.