Free-form optics for Fresnel-lens-based photovoltaic concentrators

Area of Science:

• Renewable Energy
• Optics and Photonics
• Materials Science

Background:

• Concentrated Photovoltaics (CPV) systems offer a promising path towards efficient solar energy conversion.
• High-efficiency triple-junction solar cells (over 44% efficiency) are key components in CPV technology.
• Cost-effective mass production requires high-performance optics with relaxed manufacturing tolerances and uniform illumination.

Purpose of the Study:

• To demonstrate the feasibility of achieving multiple functionalities in CPV optics using free-form designs.
• To show that complex optical requirements can be met with a minimal number of optical elements (two).
• To explore the integration of free-form optics with a Fresnel lens for enhanced CPV performance.

Main Methods:

• Utilizing the design flexibility of free-form optics to incorporate multiple optical functions.
• Designing a two-element optical system, including a Fresnel lens, for CPV applications.
• Analyzing the optical performance for high concentration ratios and uniform illumination.

Main Results:

• Free-form optics provide sufficient degrees of freedom to integrate necessary functionalities within a two-element system.
• The proposed optical design achieves high concentration ratios with uniform illumination.
• The use of free-form elements alongside a Fresnel lens allows for relaxed manufacturing tolerances.

Conclusions:

• Free-form optics are essential for advancing Concentrated Photovoltaics (CPV) technology.
• A two-element optical system, incorporating free-form design and a Fresnel lens, can meet the stringent requirements for efficient and reliable CPV.
• This approach facilitates low-cost mass production of CPV systems.