Solar Cooking
Last edited: 17 November 2022      

A study in Gujarat State of India among solar box cooker owners showed that a good part of the box solar cooker owners use their cookers for non-cooking purposes. Below are a few of the less obvious uses of a solar cooker, demonstrating its versatility. Even if a solar cooker is used regularly for everyday cooking, these special purposes may only increase its value. In several cases, a solar oven demonstrates distinct advantages over conventional ovens/cooktops in that a solar oven will not typically reach temperatures that burn.


  • November 2022: Stirling engine uses thermal solar energy to operate

Flat Plate Solar Stirling Engine-2

Developed by Leon Fainstein and Serge Broeska


Low-cost Solar Household Energy Bank - Dale Andreatta

This video shows inexpensive devices for using solar energy to fulfill a variety of household energy tasks. It is primary intended for places in the developing world, but not exclusively. Water heating, drying, and disinfection are included.

  • January 2020: Low-cost solar household energy - Dale Andreatta (This document contains two major sections. The first section is a general purpose solar heater and drier which can be used for many different purposes. It is intended to be very inexpensive and versatile. The second section is about solar water heaters that are intended to be inexpensive, but not as inexpensive as the device in the first section. These are more special-purpose devices, they only heat water, and some pressure source is needed to make them work (in other words, piped water from a tank or tap). The two sections of this document are independent, one can study the first section or the second, without reading the other section.)
Heliogen array, (vox

Heliogen prototype solar array Photocredit

  • December 2019: Artificial intelligence increases solar focus - Heliogen, is a start-up company that has incorporated artificial intelligence technology to provide very precise tracking for its solar array prototype. The large commercial scale system is aimed at energy production to fuel cement manufacturing, and potentially large scale hydrogen production to fuel vehicles. Read more...

Water pasteurization[]

Main article: Water pasteurization

Jam making/pickle making/ketchup making[]

During the summer many kinds of vegetables and fruits are available at cheap prices in the market. In many places some of these vegetables and fruits are not available in the cold seasons of fall and winter. For example ketchup or chutney (chatni) can be prepared from tomato in the solar cooker for consumption later in the year. Another example is to make jam or pickle out of certain fruits and/or vegetables for example mango, carrot, cauliflower etc. in the summer time for later consumption. Solar box cooker due to its proper range of temperature for simmering of vegetables and fruits can be used for preparation of jam, pickle and ketchup making.

Canning fruits[]

Main article: Canning
(Note that only fruits can be canned safely without the use of pressure.)

Drying of vegetables and fruits[]

Main article: Solar food drying

Drying vegetables and fruits for later use (for example ginger) is another special use of a solar oven. This is desired when there is plenty of cheap vegetables or fruits available. In some food cultures people dry onion, aubergine (eggplants), ladyfingers (okra), ginger, tomato etc. for consumption later in the year when they are scarce and also expensive.

Re-heating foods[]

  • July 2014:

Nandwani Solar Food warmers for Educational Centres in Costa Rica

Dr. Shyam Nandwani has established a program where school children heat their lunches in solar ovens every day at school.

Solar cooling[]

Solar cooling in this case usually relates to using the sun to create the necessary heat for evaporation. The resulting phase change of water from a liquid to a vapor absorbs the heat from the remaining water, and the surrounding materials will become cooler relative to the air temperature. With an ample water supply, this technique can be useful for keeping foods refrigerated without electricity. See: Pot-in-pot cooler

Making of Ghee[]

A solar oven is ideal for the making of clarified butter, known as ghee. Ghee is a very popular food in India, particularly useful because it does not need refrigeration as does butter. Ghee is made by heating butter in the solar oven over about an hour or so. It should have a very low simmering, because over 80°C the butter will burn. After some time an opaque residue will separate from the melted butter leaving a transparent liquid which is the ghee. The residue is discarded. How to ensure the solar oven does not overheat is discussed at the bottom of this page.

Heating milk[]

A box solar cooker is ideal for heating milk for drinking, cream making or other purposes, because the temperature range a solar cooker reaches will not burn the milk. Milk is sensitive to temperature over ca. 96 °C, it will simply burn and stick and an unpleasant odor will remain in the boiled milk. Here again the temperature range of the solar oven is the advantage.

Candle-making (melting wax)[]

Leftover wax candle stubs can be saved and melted down in a solar cooker, poured into a mold (paper cup, plastic bottle, coconut, etc.) to make a new candle. The wick: somehow fasten an organic-source string going from the bottom to the top of the mold.

Ironing clothes[]

AlSol irons

Traditional irons to be heated with a parabolic solar cooker.

Traditional irons did not use electricity, but had compartments where hot coals would be placed. They are still in use today. A suggestion that arrived from AlSol, is to take two irons and alternate between having one heated by a parabolic solar cooker, and one being used. Adding stones or clay into the compartment will add to the ironing time. A parabolic style cooker is best suited to provide the focused heat required for ironing.

Solar cooking advocate Pat McArdle has produced a short YouTube video which demonstrates the ability of a parabolic solar cooker to heat water for tea in the snow when the outside temperature is below 30 degrees F or 0 degrees C. In the summer the same parabolic solar cooker is used to heat a traditional iron to press a linen table cloth. Parabolic solar cookers for making tea and ironing napkins

Insect killing of grains[]

In some areas and in some seasons, the grain storage of the family may be exposed to development of small insects in the grain. These insects might be mixed with grain! Getting these insects away from the grain may usually be a difficult task to be done manually. In Gujarat I saw that some families put their insect-exposed grain, bean, peas etc. in the solar cooker a few hours for a day or two. In this way the insects are killed due the heat of the oven, while the grain, beans, peas etc. are not damaged. Afterwards the family could easily get rid of the dead insects by blowing them or using sieve.

Heating water for household uses[]

See Magnato Water Bottle Heater.

Coffee roasting[]

Main article: Coffee roasting

Soil sterilization[]

Main article: Soil sterilization

Making mosquito repellant[]


Ventilation/temperature adjusting[]

During the study in Gujarat I observed that some families decreased the temperature and moisture developed in their solar cookers, by slightly opening the top glass lid of their cooker by temporarily creating a gap for the oven. This is indeed an easy and effective way to control the temperature/moisture within the oven. One can for example place a coin or a small glass ball to keep the top sash open. This is necessary specially when the sun is high and one should avoid high temperatures for some of the above-mentioned special uses for example when one is heating milk.

Distillation of water[]

Main article: Water distillation


Main article: Solar autoclave


Solar energy can be used to preheat food that is then cooked on a conventional stove.

Main article: Preheating

Home heating[]

It has been reported that people have built a solar cooker to heat rocks for keeping warm at night. Adding a little water to the remaining rocks adds nice warm humidity to the inside air.

Solar thermal electricity generation[]

Solar reflectors similar to those used with solar cookers, but built at a much larger scale, can be used to generate enough electricity to serve community needs. Typically, the sun's energy is used to create steam, converting it to mechanical energy with a turbine, which powers a generator to produce electricity. .


Audio and video[]

  • February 2022:

5-2 Solar cooking plastic into boat parts - CONSOLFOOD 2022-2

  • January 2020:

Simple Solar Household Energy - Dale Andreatta

See also[]

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