Common mirror manufacturing methods
Concentrator mirrors are manufactured to balance reflectivity, durability, cost, and optical accuracy. Choices include silvered glass, anodized aluminum, and film-based reflectors, each produced by different processes.
Manufacturing approaches:
- Tempered silvered glass mirrors: glass is coated with a reflective metal layer (silver or aluminum) and protected with backing layers. These offer high reflectivity and durability.
- Aluminum mirrors: formed and polished aluminum sheets may be anodized or coated to protect against corrosion.
- Reflective films: plastic films backed by aluminum deposition are applied to a substrate; cheaper and lighter but typically less durable.
Quality control focuses on:
- Optical figure: the surface curvature must match design within tight tolerances to maintain focus.
- Reflectivity across the solar spectrum: high broadband reflectance improves energy capture.
- Durability: coatings and sealants to resist abrasion, moisture, and UV degradation.
Manufacturers choose materials and processes based on system life expectancy, environment, and cost targets.