Piezoelectric Lens Tracking for Solar Concentrator Cost Reduction
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Solution Overview
Problem
Photovoltaic systems for generating electricity from sunlight are not competitive with fossil-fuel generated electricity due to high costs, necessitating a reduction in overall system and module assembly costs.
Innovation Solution
A photovoltaic solar concentrator using thin, small-area solar cells on a low-cost stainless steel or polymer substrate with a moveable lens assembly that tracks the sun using piezoelectric actuators to concentrate sunlight, enhancing efficiency and reducing costs through batch fabrication and fluidic self-assembly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional photovoltaic systems are used, then electricity can be generated from sunlight, but the system cost is high and not competitive with fossil-fuel generated electricity
Solution Approach 1:
The system divides the photovoltaic module into separate components: a low-cost substrate structure and small-area high-efficiency solar cells. The substrate is segmented into multiple layers including support substrate, reflective layer, and transparent substrate, allowing independent optimization of each component for cost and performance.
Solution Approach 2:
A transparent substrate acts as an intermediary between the incoming sunlight and the solar cells, allowing light to pass through while providing structural support and enabling the use of flexible, thin-film solar cells that can be conformally arranged on the curved surface.
2Ease of manufacture
If small-area photovoltaic solar cells are used to reduce cost, then manufacturing cost decreases, but the area for light absorption is reduced
Solution Approach 1:
The system uses a curved or flexible substrate that allows small solar cells to be arranged in a three-dimensional configuration, maximizing the surface area exposed to sunlight from multiple angles and throughout the day, thereby compensating for the small individual cell areas.
Solution Approach 2:
The patent transitions from flat two-dimensional solar cell arrays to three-dimensional curved surfaces, allowing sunlight to illuminate the cells from multiple angles and throughout the day, effectively increasing the functional light-absorption area without increasing the planar footprint.
3Productivity
If a moveable lens assembly is added to track the sun, then sunlight concentration efficiency increases, but device complexity increases
Solution Approach 1:
The lens assembly is made movable with respect to the substrate, allowing it to track the sun's movement across the sky. This dynamic adjustment maintains optimal sunlight concentration on the solar cells throughout the day, significantly improving energy generation efficiency.
Solution Approach 2:
The system incorporates a feedback control mechanism where light sensors detect the position of maximum sunlight intensity, and this information is used to automatically adjust the lens position, enabling the system to self-optimize without external intervention.
4Measurement precision
If piezoelectric actuators are used to move the lens, then precise tracking of the sun is achieved, but the device complexity and manufacturing cost increase
Solution Approach 1:
The patent replaces traditional mechanical motors and gear systems with piezoelectric actuators, which provide precise positioning through electrostatic actuation. This substitution eliminates complex mechanical transmission components while achieving high-precision sun tracking through direct electrical control.
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 reduces costs and increases efficiency by using thin solar cells and a moveable lens assembly to concentrate sunlight, improving the competitiveness of photovoltaic systems with fossil-fuel generated electricity.
Implementation Method 1
a lens is located above each photovoltaic solar cell to concentrate the sunlight onto that photovoltaic solar cell
Implementation Method 2
A plurality of piezoelectric actuators are provided on the substrate to move each lens to maintain the sunlight concentrated onto each photovoltaic solar cell
Implementation Method 3
photovoltaic solar cells which can be batch fabricated and assembled onto a low-cost stainless steel or polymer substrate
Data Source
AI summary
A photovoltaic solar concentrator is disclosed with one or more transverse-junction solar cells (also termed point contact solar cells) and a lens located above each solar cell to concentrate sunlight onto the solar cell to generate electricity. Piezoelectric actuators tilt or translate each lens to track the sun using a feedback-control circuit which senses the electricity generated by one or more of the solar cells. The piezoelectric actuators can be coupled through a displacement-multiplier linkage to provide an increased range of movement of each lens. Each lens in the solar concentrator can be supported on a frame (also termed a tilt plate) having three legs, with the movement of the legs being controlled by the piezoelectric actuators.