Solar Box Cooker

By Nick Bliss

First attempt at making a solar-oven, testing it by cooking eggs and bannock.

Instructions

I downloaded the instructions for the cooker from bush craft uk at the following link http://www.bushcraftuk.com/downloads/pdf/solarbox.pdf

It is self explanatory and very simple. In short place a box inside the other. Line the inner box with foil. Make a rear reflector and cover with foil. Insulate between the 2 box’s. Place a sheet of glass over the top. Place a black cooking pot inside the box. The following pictures paint a thousand words.

The Test

I placed 2 eggs inside the cooking pot (without water). I took one out after 40 mins. The white was still a little soft and the yoke still runny. (see pics for result).

I took the second out after 2 hours, the result was a hard boiled egg (see pics for result).

The outside temperature was around 30 C. The test was carried out between 1030-1230 in sunny Cyprus.

The same test was carried out with one egg placed in a black cooking pot left out in the sun (not in a solar box cooker).The result was an unchanged raw egg.

Egg Atfer 40mins in Solar Cooker

egg-40mins

Egg After 2 Hours in Solar Cooker

egg-2hours

Summary

Very simple and very effective. Further testing cooking other product will be conducted.I aim to build a solar box cooker with slightly more readily available items. Polythene to replace the glass, a space blanket to replace the kitchen foil and using one cardboard box placed in a hole, results to follow.

I am lucky to have the Cyprus sun but the UK seems to have similar weather at the moment so there is no reason why it wouldn’t work.

Cooking Bannock

The mix was placed in the pan at about 0920 and taken out at 1220. It could of done with another 30 mins by my reckoning but as a first attempt its great. There is a nice crust to the outer and the bottom was not burnt (as most of my open fire cooked Bannock seems to be).

The weather today is much cooler at around 28C with a strong breeze (a wind break was erected to keep down the affect on the cooking process) so I was pleasantly surprised by the results.

cooked-bannock

bannock-cooked-and-cut

bannockcloseup

Huge thank you to visitor Nick Bliss for making this superb article to share with others through NaturalBushcraft.

Comments (4)

One thing we're not short of in SA is sunlight and I',ve used a Solar box cooker often, right up to the stage of a full roast chicken, potatoes & veg!
The trick is to follow the sun light, ie. keep turning the box so that you have optimum
sunlight at all time, that way you can shorten your cooking times and obtain good results.
Unfortunatly there are no standards for Sunlight, so you must stay with it throughout the entire cooking process, it's not a leave and forget situation!