How to Make Solar Troughs Catch More Sunlight at Their Ends

This patent describes adding special reflective extensions and caps to the ends of a single-axis tracking solar trough to capture more sunlight that would otherwise be lost, making the collector more efficient.

What it covers

This patent describes a concentrating solar energy collector that tracks the sun along one axis. It includes a main reflective trough and one or more solar receivers positioned to catch the reflected sunlight (Claim 1). The key invention is an "end unit" attached to at least one end of the main reflector. This end unit contains a "reflector extender" that has the same curved shape as the main trough, effectively making the reflective surface longer (Claim 1). This extender is designed to direct incoming sunlight towards the solar receivers, especially the ones located at the ends of the receiver row (Claim 2). For example, if the sun is low in the sky, the extender ensures that the receiver at the very end of the trough still gets reflected light (Claim 8). The end unit also includes an "end cap" that covers the outer end of the reflector extender (Claim 1).

What it doesn't cover

• —Solar collectors that do not track the sun along a single axis, such as fixed-position panels or systems that track on two axes.
• —Collectors where the reflector extender's curved shape does not match the cross-sectional shape of the main reflective trough.
• —Systems that use a receiver extension (an optional part of the invention) that contains solar cells, as the patent specifies it does not (Claim 3).
• —Non-concentrating solar energy collectors, like standard flat-plate solar panels that do not focus sunlight.
• —Collectors that do not include both a reflector extender and an end cap as part of the end unit (Claim 1).

The clever bit

The clever part is recognizing and precisely engineering a solution for the 'end-loss' problem in single-axis tracking parabolic troughs. By adding a reflector extender that mirrors the main trough's shape and an end cap, the system effectively extends its light-gathering capability, capturing sunlight that would otherwise be wasted, especially at varying sun angles.

Why it matters

Concentrating solar power (CSP) systems, which use mirrors to focus sunlight, often lose efficiency at the ends of their long troughs because some sunlight misses the collector or the receiver. This patent addresses that specific problem, aiming to increase the total amount of sunlight captured and converted into energy. By improving efficiency, these systems can generate more electricity from the same footprint, potentially lowering the cost of solar power.

Real-world examples

• 1.Parabolic trough concentrated solar power (CSP) plants
• 2.Concentrated photovoltaic (CPV) systems using trough reflectors
• 3.Any single-axis tracking solar collector designed for high efficiency