Which is better for concentrating sunlight ?

  • Context: Undergrad 
  • Thread starter Thread starter anjanamurthy
  • Start date Start date
  • Tags Tags
    Sunlight
Click For Summary

Discussion Overview

The discussion revolves around the efficiency of different configurations of parabolic reflectors for concentrating sunlight, specifically comparing central axis (Cassegrain) and off-axis designs. The context includes considerations for solar illumination projects that require sun tracking.

Discussion Character

  • Exploratory, Technical explanation, Debate/contested

Main Points Raised

  • One participant questions which configuration is better for efficiency between central axis (Cassegrain) and off-axis reflectors.
  • Another participant suggests that for a simple solar reflector, efficiency largely depends on the effective area, noting that off-axis reflectors may have a slightly reduced area due to the projection shape, while Cassegrain systems may waste central area for a secondary reflector.
  • Several participants emphasize the importance of tracking accuracy and feasibility in determining which reflector type is better for direct solar illumination projects.
  • There are inquiries about the size of the object for sunlight concentration and the power requirements, indicating that these factors influence the choice of reflector configuration.

Areas of Agreement / Disagreement

Participants express differing views on the efficiency and practicality of the two reflector types, with no consensus reached regarding which is definitively better for the specified application.

Contextual Notes

Participants have not fully defined the assumptions regarding tracking accuracy, power requirements, or the specific application context, which may affect the discussion outcomes.

anjanamurthy
Messages
3
Reaction score
0
which is better for concentrating sunlight ??

I m doing a project on solar illumination . I wanted to know which configuration of parabolic reflector/ collector is better in terms of efficiency - central axis (cassegrain) or off axis ??
 
Science news on Phys.org


For a simple solar reflector where no high quality image is required, it's largely down to the effective area of the reflector. This may be reduced for an off axis reflector by a small amount due to the projection turning a circle into an ellipse, with a slightly smaller area - but the Cassegrain system 'wastes' all that central area for the secondary reflector.
 


Well this is for a direct solar illumination project which requires tracking of sun. So if we consider that also .. which of the two would be better ??
In terms of tracking accuracy required and feasibility to track ...
 


anjanamurthy said:
Well this is for a direct solar illumination project which requires tracking of sun. So if we consider that also .. which of the two would be better ??
In terms of tracking accuracy required and feasibility to track ...

What are your thoughts on reasons why one might be better over the other?
 


anjanamurthy said:
Well this is for a direct solar illumination project which requires tracking of sun. So if we consider that also .. which of the two would be better ??
In terms of tracking accuracy required and feasibility to track ...

How well does need it to track? What size object do you want to concentrate the sunlight on? How much power do you want? (a few Watts or several kW?)
So far it's 'how long is a piece of string?'
 
Last edited:

Similar threads

Undergrad Concentrating sunlight to accomplish projection (Art project)
  • · Replies 4 ·
Replies
4
Views
3K
Undergrad Is This....Right? Splitting LED colors is not working for me
  • · Replies 40 ·
2
Replies
40
Views
5K
Misc. My new solar cooker/solar drier 1/5 scale model: It's smoking!
  • · Replies 7 ·
Replies
7
Views
2K
Undergrad Condenser lens retrofit for a lighting application
  • · Replies 24 ·
Replies
24
Views
3K
Undergrad Two mirrors to focus sunrays into a tiny spot -- possible?
  • · Replies 6 ·
Replies
6
Views
4K
Graduate Sunlight Intensity Concentrator - Idea to boost solar energy
  • · Replies 24 ·
Replies
24
Views
4K
Undergrad Experimental demonstration of an absorption spectrum
  • · Replies 7 ·
Replies
7
Views
3K
Graduate How can a 1 kilometer body (3i/Atlas) flip 180 degrees suddenly?
  • · Replies 9 ·
Replies
9
Views
998
Undergrad Pool Solar Heating - Help orienting the roof-top solar collector please
  • · Replies 1 ·
Replies
1
Views
2K
Undergrad EM waves have no mass but they do have momentum?
  • · Replies 21 ·
Replies
21
Views
3K