What are Fresnel reflectors and why use them?

Flat-segment concentrators that lower cost

Linear Fresnel reflectors use many long, narrow, flat or slightly curved mirror strips to approximate a parabolic surface, focusing sunlight onto a fixed receiver above the field. The simplified geometry reduces material and structural costs compared with parabolic troughs.

Benefits and trade-offs:

  • Lower cost: simpler mirrors and supports make manufacture and installation cheaper.
  • Reduced wind and structural loads: flatter mirror profiles are less affected by wind.
  • Slightly lower optical efficiency: segmentation and cosine effects lead to increased optical losses versus continuous parabolic mirrors.

Practical applications:

  • Medium-temperature heat production for power generation or industrial processes.
  • Projects where lower capital cost is prioritized over peak efficiency.
  • Easy integration with fixed receivers and simplified piping runs.

Fresnel systems are a pragmatic compromise between cost and performance, particularly for large fields and modest temperature requirements.