Compound Curved Solar Concentrator Array for Passive PV Cooling

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Solution Overview

Problem

Existing sunlight-concentrator devices for photovoltaic systems face limitations in achieving high concentration factors while avoiding overheating and optical losses, with current technologies either requiring active cooling or suffering from fabrication errors and material deterioration.

Innovation Solution

A sunlight-concentrator device utilizing an array of optical units with compound curved primary concentrators and a secondary concentrator for further homogenization and concentration, designed to achieve concentration factors between 10 and 150, featuring a simple and lightweight design that dissipates heat passively and reduces production costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If a primary concentrator with a wide reflecting disk (paraboloid surface) is used to achieve high concentration factors (30-1000), then the concentration factor is improved, but the photovoltaic cells overheat requiring active cooling systems

Engineering Contradiction:
Improveconcentration factorVSAvoidphotovoltaic cell temperature
Core Design Contradiction:
Illumination intensityVSTemperature

Solution Approach 1:

The patent divides the single wide reflecting disk into multiple smaller reflecting surfaces arranged in a specific geometric configuration. Each smaller reflector concentrates sunlight independently, distributing the thermal load across multiple photovoltaic cells rather than concentrating all energy on a single focal point, thereby reducing overheating while maintaining high overall concentration factor

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent transitions from a two-dimensional paraboloid surface to a three-dimensional arrangement of multiple reflecting surfaces at specific angles and positions. This spatial distribution in multiple dimensions allows sunlight concentration while dispersing heat generation across a larger volume and multiple cell surfaces, eliminating the need for active cooling

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Illumination intensity

If lens-type optical units are used to achieve concentration factors between 20 and 1000, then the concentration factor is improved and passive heat dissipation is achieved, but optical losses occur due to reflection on outer surfaces, reduced tolerances, and fabrication errors

Engineering Contradiction:
Improveconcentration factorVSAvoidoptical losses
Core Design Contradiction:
Illumination intensityVSLoss of energy

Solution Approach 1:

The patent replaces lens-based optical concentration (refraction) with reflecting surface-based concentration (reflection). This substitution eliminates optical losses associated with lens surfaces, material absorption, and fabrication tolerances, as mirrors can achieve high reflectivity (>90%) and are more tolerant of positioning errors and surface imperfections

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent employs composite structures combining multiple reflecting surfaces with specific geometric configurations, where each surface is optimized for its specific function. This composite approach allows the system to achieve high concentration factors while maintaining tolerance to fabrication variations and minimizing overall optical losses through the collective performance of multiple reflective elements

Inventive Principle:
Principle #40Composite materials

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The solution enables efficient sunlight concentration with passive heat dissipation, eliminating the need for active cooling and minimizing optical losses, while being easy and inexpensive to produce, thus enhancing the performance and cost-effectiveness of photovoltaic systems.

Implementation Method 1

a compound parabolic primary concentrator with an inlet aperture for direct entry of sunlight, an outlet aperture for exit of the concentrated sunlight towards the respective secondary concentrator, and a reflecting curved internal surface, for example a mirror surface

Methodology Applied
Scientific EffectReflection: Reflection

Implementation Method 2

designed to receive the sunlight directly and to concentrate the sunlight received onto a respective secondary concentrator

Methodology Applied
Scientific EffectConcentration: Focusing

Implementation Method 3

a secondary concentrator for further homogenization and concentration

Methodology Applied
Scientific EffectConcentration: Focusing

Implementation Method 4

further homogenization and concentration of the sunlight received from the primary concentrator

Methodology Applied
Scientific EffectHomogenization:

Implementation Method 5

a plurality of photovoltaic cells, designed to convert sunlight into electrical energy

Methodology Applied
Scientific EffectPhotovoltaic effect: Photovoltaic Effect

Implementation Method 6

two-dimensional compound parabolic concentrator devices, comprising a pair of surfaces, each of which has, in the direction of arrival of the sun rays, a section constituted by a branch of parabola

Methodology Applied
Scientific EffectReflection: Reflection

Data Source

PatentEP2176890A2A sunlight -concentrator device for a photovoltaic -generating system
Publication Date: 2010.04.21 CPOWER SRL

AI summary

In a photovoltaic power generating system (1) having a plurality of photovoltaic cells (2), a -sunlight-concentrator device (3) is equipped with a plurality of optical units (4), which are provided with respective primary concentrators with a compound curved surface (5; 23; 27; 30; 31; 32; 34; 37), each of which has an inlet aperture (6) for the direct entry of sunlight, an outlet aperture- (7) for exit of the concentrated sunlight towards a respective photovoltaic cell (2) and an optical axis (8) traversing the inlet aperture (6) and outlet aperture (7). The optical units are seamlessly arranged in an array form.