Building a Parabolic Solar Oven
by Adam Weller
(Basingstoke, Hampshire, United Kingdom)
The completed project
I just submitted a description of my solar oven, but was asked if I could add some more details, so I am making another report.
There are relatively few parabolic solar oven stories, perhaps because they are more challenging to make. I built one as an exploration of solar cooking and was pleasantly surprised. I live in England, which is certainly not the best place for a solar oven, due to usual lack of sun, which prompted me to make it quite large (Basingstoke, where I live, is on the same latitude as Calgary, Canada). I made it to have a 1.2m (4ft) diameter and 1 square metre of solar collecting area.
I built it from scratch into a parabolic shape using a single plywood sheet (1.2m by 2.4m, or 4ft by 8ft). The design for the wooden pieces was fairly complex, with two parabolically shaped main ribs holding up eight concentric rings, which were further supported by eight smaller ribs (see picture).
Using advice on this website, I used Mylar for the reflective surface, which was indeed cheap although I feel efficiency would have been much greater if I had taken extra expense. I glued a total of around 200 small mirror segments onto the wooden frame.
It took a while to build, about two weeks of work, but in the end it ended up being light and easy to point in the right direction. It is mounted on a circular base (which had been used for a fire pit)and rotates on it - important as it needs directional adjustment every 15-20 minutes. The total cost of the materials was around £40 (about $60).
It heats up very quickly and I use it for cooking some small food items, for example eggs which fully cook in 10 minutes in good conditions. It also boils water quite quickly, and so I have been able to use it to make tea (and coffee). I have also used it to cook bread; a 350g loaf cooked in a little over an hour, in poor conditions.
A parabolic oven is obviously a more work-intensive endeavor than other solar ovens, but my final result looked good and worked well.
Great Detail Adam, thank you for adding more information, and the pictures are sure helpful in understanding your design more clearly.
The frame looks nice and really well built.
I am sure this will generate some interest from others who have an inclination to create their own or similar solar cookers.