Best Method of Focusing Solar Power

In summary, if you want to make a solar powered distillation machine, you should probably get a parabolic dish, glue on small mirrors, or take an acrilyc plexiglass mirror and place it on the fiberglass dish.
  • #1
Thundagere
159
0
If I keep this up, I'm going to get a rep around here :).
So, I recently acquired a fiberglass satellite dish which I plan to use for building a cheap, solar powered distillation machine. The idea is to have the dish, calculate the focal point, and run a double glass plated chamber at the focal point. THis allows light in, let's it get heated, then retains the heat long enough for it to boil. Keep in mind, as a high school freshman, this is partially for fun, but I might enter it in a science fair. I want this to be as resourceful and documented as possible.
So, here's the real question. I'm thinking of either a) Taking an acrilyc plexiglass mirror and placing it on the fiberglass dish, then putting it in an oven and molding it into the parabolic shape, or
b) Gluing on hundreds of small mirrors.

I want to know, would the first idea work or would the mirror get too warped and make light go through diffiuse reflection, or would it still be specular? Which method would be best for my project of boiling water?
With the amount of water I have, I need about 298000 J. The sun gives off about 1000 W/m^2, I believe (a bit more, but I'm averagin and including nightfall). That's just background info, but what do you guys think?
 
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  • #2
Any ideas on this? I don't mean to go crazy asking but I'm honestly not sure if I can keep specular reflection when the acrilyc melts.
 
  • #3
Thundagere said:
Any ideas on this? I don't mean to go crazy asking but I'm honestly not sure if I can keep specular reflection when the acrilyc melts.

It will be tough to mold it properly in my opinion. Glueing hundreds of tiny mirrors is something that I've seen be done before, but I can understand why that wouldn't be your favourite approach.
 
  • #4
A few shaving mirrors I would have thought would do the trick
 
  • #5
I'd say get about 10-20 small mirrors and place on the dish. They don't need to be curved, and it might be easier than making one big curved mirror or using hundreds of small ones. It really depends on how much time you want to spend on this.
 
  • #6
If the parabolic dish is smooth enough you may use aluminized mylar. It's thin, light weight, cheap, and highly reflective.
 
  • #7
As I mentioned before, and Drakkith re-mentions: your focusing doesn't have to be excessively accurate or excessively granular. If your heating vessel is, say, 4 inches in diameter then your mirrored tiles do not need to need much smaller than 4 inches. As long as the "beam" from each mirror is smaller in diameter than the heating vessel, you're good to go.

You'd only need a smooth surface if you wanted a point focus.
 
  • #8
Last edited by a moderator:

1. What is the best method of focusing solar power?

The best method of focusing solar power depends on several factors, such as the location, size of the solar power system, and the desired outcome. Some common methods include parabolic troughs, heliostats, and photovoltaic panels. Each method has its own advantages and disadvantages, so it's important to consider these factors when choosing the best method for a specific project.

2. How does a parabolic trough work to focus solar power?

A parabolic trough is a curved, reflective surface that concentrates the sun's rays onto a single point. This point is where a receiver is located, which absorbs the concentrated solar energy and converts it into electricity. The trough is typically mounted on a tracking system to follow the sun's movement throughout the day, maximizing the amount of solar energy captured.

3. Can solar power be focused without using mirrors or lenses?

Yes, it is possible to focus solar power without using mirrors or lenses. One method is through the use of photovoltaic (PV) panels, which directly convert sunlight into electricity. These panels are typically made of silicon and are designed to absorb and convert as much sunlight as possible.

4. What are the benefits of using heliostats for focusing solar power?

Heliostats are large mirrors that track the sun's movement and reflect sunlight onto a central receiver, similar to parabolic troughs. One of the main benefits of using heliostats is their ability to focus sunlight onto a smaller receiver, resulting in higher temperatures and more efficient energy conversion. They also have the advantage of being able to be installed on uneven terrain.

5. What are the main challenges with focusing solar power?

One of the main challenges with focusing solar power is the need for consistent and direct sunlight. Cloudy or overcast days can significantly reduce the amount of solar energy that can be captured and focused. Additionally, the cost of materials and maintenance for these systems can be a barrier for widespread use. However, with advancements in technology and increased demand for renewable energy, these challenges are being addressed and overcome.

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