Solar trough cooker designs

Last edited: 28 September 2015

Gosun kicker-04 — The GoSun is an example of a solar **trough cooker** used with an evacuated glass tube.

Solar trough cookers use a reflector to capture light that has a curved parabolic cross-section, but continues as a straight trough in the other direction. Instead of focussing the light at one spot like a typical bowl shaped parabolic solar cooker, the light is reflected along what is known as a focal line.

This straight line of concentrated light is often directed onto an evacuated glass tube chamber containing food to be cooked. The two technologies work well together, as the well-insulated tube allows for less reorientation to the sun. Several commercial solar cookers using this combined approach are available for sale. Linear arrays of reflectors are also suited for larger steam generating cooking systems.

Because construction of the trough reflector requires bending only in one direction they can be easier to fabricate than a parabolic dish, but they do not offer the option of easily heating a single cook pot.

The trough can be aligned on a north-south axis, and rotated to track the sun as it moves across the sky each day, or faced in a southerly direction requiring no reorientation to the sun, with slightly less efficient output.

Advantages and disadvantages

Advantages

The curved trough reflector is efficient at gathering and focussing sunlight along a focal line
Works well with evacuated tube cooking chambers, maintaining higher temperatures with intermittent sunlight conditions in a compact package

Disadvantages

The trough design does not focus sunlight onto a standard cook pot
Not particularly well suited for home enthusiast construction

What can you cook?

Any food cut into pieces that will fit conveniently into a sliding tray inside of an evacuated tube chamber or secured to a rotating skewer. Because the tube is used primarily in a horizontal position, boiling liquids, and cooking rice and beans, are usually not done with trough cookers.

Types of solar trough cookers

Personal

Compact and efficient trough cookers are available commercially, though somewhat expensive with the evacuated tube and a sturdy reflector.

Examples of personal solar trough cookers

Institutional

Systems using the linear arrays boil water to create steam to cook large amounts of food. However, parabolic arrays may be better suited for tracking the sun for this purpose.