Sunbrella - The latest design for a simple portable stove.

This is a simple design, that is easy to make, and easy to transport. The sunlight is reflected off of the inner surface of the umbrella and onto the underside of the kettle. As it is so simple, without any wind stabilisation, it is ideally suited for summer days without any wind, and sunk into the sand on a beach. Unfortunately since making this stove we have had no sunshine so I have not been able to check its performance.

Safety

Do not look at the reflection of the sun at any time. Please refer to SAFETY instructions before you begin.

Parts required:

The umbrella is the most important item. I have found that it needs to be a '16 segment' umbrella to get a good parabolic shape. Once you have found your umbrella, then you need to get hold of the reflector. Please refer to Anocoil for information on suppliers.

Description

Size

Material

Quantity

Umbrella (with 16 segments)

Diameter = 1.25m open

as supplied

1

Reflective segments

Tapered 250mm to 50mm x 620mm long.

Anocoil aluminium

16

Grill

350mm long x 12mm wide x 2.5mm thick

Mild steel bar

1

 How to make it:

The only tools you should need are:

Measure your umbrella to determine the size of the reflective segments you require. In my case I needed segments 620mm long, and tapering from 250mm down to 50mm. Using a Stanley Knife, score through the aluminium once and then bend the fold and it will break off. Please be careful with your fingers! The peal off the thin plastic covering (if fitted) and slide the reflector into place. If you have the dimensions correct, it should tuck under the metal ribs of the umbrella at the centre and outer edge, but not in the middle. Once all 16 segments are in place you have to determine the best position for the grill. Take the 'Sunbrella' outside and aim it at the sun. Take a blank sheet of paper, make a hole in the centre, and pass it over the umbrella handle. Move the paper up and down until you find the point of most intensity. Be careful not to dazzle yourself, or burn yourself as the paper may catch fire! Once you know where the focal point is, you can take the Sunbrella inside again and fix the grill to the handle at the appropriate height.

Solar Cookers

Prototypes

Peru Children's Trust

Solar1000

 Last updated 8th November 2000