'Parabolic solar cooker' from Recycled plastic

Am involved with Renewable Solar energy small project through the usage of Solar parabolic cookers and  looking to use recicled plastic to build the solar parabolic cookers…

wonder if anyone else has already try this item …?

Sounds like a great idea.

How will you be applying the reflective coating?

Are here some amigos from Sud American Countries who have implemented ‘small comunitary recycling plastic projects’ ? if there are some, please would like to know if their experience as to explore potential replication of this interesting project in the country of Paraguay Muchas Gracias!

Interesting paper:

Solar Cooking: Why is it Not Yet Global?

June 2014 – Food Culture and Society An International Journal of Multidisciplinary Research 17(2)

https://www.researchgate.net/publication/263094576_Solar_Cooking_Why_is_it_Not_Yet_Global

It also mentions why an accurate parabolic mirror can cause problems.

Sure, that’s exactly the difference between sphere and parabola. The link has very good images. However, because the real mirror may not be as perfect as the images, it’s better to have at least in theory a good focus, so in practice will go off a little. No difference in small sizes for cooking though.

Gosol is a nice technology, unfortunately I can’t find free plans since 2013.

If you want something bigger, to gather more energy, then you are probably better off constructing something like this:

https://gosol.solar/impact

 

Hi @arisberd

A spherical mirror has a focal point that will be good enough for cooking, despite a small amount of spherical aberration.  In fact, many optical telescopes use spherical mirrors and still cope well despite the imperfect focus.  See http://slittlefair.staff.shef.ac.uk/teaching/phy217/lectures/telescopes/L07/index.html

If anything, a slight blurring of the focal point will help. Nobody wants to burn a hole though the base of their cooking pot 😉

 

Well, to be precise, the parabolic disc might even need to have different moulds for each triangle (it depends on where the focus will be). But as @frogfall said, for cooking reasons that wouldn’t be the point (it would really be for bigger mirrors).

As for the hemisphere (or an arch), I am not sure it will work, as the pot is relevantly small, you should first check if it does much focus. (for example to have a power of 1000W you will need 1,3 meters diameter of a “circle”).

About the aluminium foil, we used wood glue on plywood with very good results. I am curius to find out how would that be on plastic.

 

it would be a real challenge to make the parabolic triangles from plastic!!

I would have thought that moulding sectors of a parabola would be relatively easy, by using the granule/oven/bowl moulding technique, as shown in many of the videos here.

Actually, the sectors don’t even need to form part of a true parabolic dish – as it is possibe to get a decent enough focus from a partial hemisphere for cooking purposes.  And it it might be easier to find a large partly spherical item to make a mould from.

The reflecting coating is usually made with aluminium foil.

Held in place with adhesive?

Intresting project blaso.

You can take suggestions from Solar Cookers International.

http://solarcooking.org/plans/default.htm?redirect=no

We ‘ve tried some of them, I would suggest the panel type, as it’s the easiest to make and use (in generally >25 C). However, there is not so much need to replace wood with plastic (exception: if you want to make a rainproof, but probably in rainy days there is not so much sun). As for the parabolic one, it would be a real challenge to make the parabolic triangles from plastic!!

The reflecting coating is usually made with aluminium foil.