Solar - Linear Fresnel lenses

Introduction

Linear Fresnel lenses focus sunlight in one dimension onto a strip. They are used in Concentrated Thermal Solar (CSP) systems to focus sunlight onto heat collection pipes and in low concentration photovoltaic (CPV) systems to concentrate sunlight onto strips of PV material. The optimal concentration ratio of a primary lens is in the region of x15 - x20 suns. If a secondary optic is used the total system concentration ration can be up to x50 with reasonable tracking tolerance.

Lens Dimensions
Film Optics has designed and manufactured a wide variety of lens designs. Lenses can be of any reasonable length required – subject to handling limitations. Multiple sections can be used to create wider structures. The optimal concentration ratio of a primary lens is in the region of x15 - x20 suns. The optimal focal length is usually 1x – 2x lens width.

Lens Shapes

We typically produce 3 types of lenses:

Flat Lenses - these can also be produced as multiple strip parquets in one sheet.
Curved lenses - these lenses show improved optical properties when compared to flat lenses.
Faceted Lens - constructed of multiple sections this design is used for wider lenses and give the optimum balance of performance and ease of construction.

Lens Construction

The lenses are made on acrylic (PMMA) film using a proprietary acrylic lacquer on a continuous reel-to-reel machine.
Film lenses - typically used stretched over frames under a glass cover. This solution represents a low weight, low cost solution for smaller structures.
Rigid lenses - The lens film is bonded to a PMMA or glass sheet to provide rigidity

Our Service

Film Optics offers a bespoke lens design and development service to ensure each lens perfectly matches the requirements of a customer's system. This service includes:

Lens design and performance modelling using proprietary in-house software packages
Production tooling design and manufacture
Initial hand cast test samples
'Pilot plant', small scale test manufacturing
Full scale commercial manufacturing.

Samples and Evaluation Kits