Skip to content
Know.itKnow.it
Create an animated lesson
On request

This article is free to read. Creating a lesson uses your daily or stored credits; review the language and settings before starting.

How does a solar cooker work?

ScienceLesson on requestFree to readयह पेज हिंदी में पढ़ें

Quick answer

A solar cooker uses mirrors or shiny panels to direct sunlight onto a dark pot, which absorbs the light and turns it into heat. A clear lid and insulated walls trap that heat, so a box cooker can reach about 100 to 150 °C. Parabolic dishes concentrate sunlight further, reaching frying temperatures.

A solar cooker works by collecting sunlight with reflective surfaces, turning it into heat on a dark cooking pot, and trapping that heat with insulation or a clear cover. Box cookers typically reach about 100 to 150 °C, while concentrating dish cookers get much hotter.

Step by step

  1. The cooker is turned to face the sun, with its reflector angled to bounce extra light inward.
  2. Sunlight passes through the clear lid and falls on the black pot and tray.
  3. The dark surfaces absorb the light and convert it to heat, warming the food inside.
  4. The clear lid and insulated walls stop warm air escaping, so the temperature keeps climbing.
  5. The cooker is re-aimed every hour or so to follow the sun until the food is cooked.

Key things to understand

  1. Shiny reflectors made of aluminium or mirror glass redirect extra sunlight onto the cooking area.
  2. A dark, matt pot absorbs most of the visible and near-infrared light and converts it into heat.
  3. In a box cooker, a glass or plastic lid lets sunlight in but blocks warm air from escaping by convection.
  4. Insulated walls slow heat loss, so the inside of the box climbs well above the outdoor temperature.
  5. Parabolic dish cookers focus sunlight onto a single point, reaching temperatures high enough for frying.

Labelled diagram

  1. Reflector

    Shiny panel bounces extra sunlight through the lid into the box.

  2. Glass lid

    Lets sunlight in while blocking hot air from escaping.

  3. Black pot

    Absorbs light and turns it into heat that cooks the food.

  4. Insulated box

    Thick walls slow heat loss so the inside stays hot.

How a solar box cooker traps heat

Real-world examples

  • The Shirdi temple kitchen in Maharashtra uses dozens of Scheffler dish concentrators to raise steam for cooking meals.
  • Families in sunny parts of Rajasthan and Gujarat use solar box cookers to cook dal and rice at midday.
  • Folding panel cookers are used in refugee camps where firewood is scarce.
  • Campers use lightweight parabolic or tube cookers to heat water without carrying fuel.

Common mistake

✗ Myth: A solar cooker needs hot weather to work.

✓ Fact: It needs strong, direct sunlight, not warm air. A box cooker can work on a clear, cold winter day, while a hot but hazy or cloudy day may barely cook food.

People also ask

How hot can a solar cooker get?
A well-built box cooker usually reaches about 100 to 150 °C inside, enough to boil, bake and simmer. Panel cookers are somewhat cooler. Parabolic dish cookers concentrate sunlight onto one point and can exceed 200 °C at the pot, hot enough to fry. Actual temperatures depend on sunlight strength and design.
What is the principle of solar cooker?
A solar cooker relies on three effects: reflection, absorption and heat trapping. Reflectors concentrate sunlight onto the cooking area, dark surfaces absorb it and convert it to heat, and a clear cover with insulation keeps that heat from escaping. Together they raise the temperature enough to cook food.
Why is glass used in solar cooker?
Glass lets visible sunlight pass easily into the box, where the black surfaces absorb it. The glass then acts as a barrier, stopping warm air from rising out and partly blocking longer-wavelength infrared radiation from the hot interior. This traps heat inside, much like a greenhouse.
Does a solar cooker work on cloudy days?
Only poorly. Solar cookers depend on direct sunlight, which clouds scatter and block. Thin, passing cloud slows cooking, while heavy overcast skies leave too little energy to cook effectively, so many households keep a conventional stove as backup.
Why are solar cooking pots painted black?
Black surfaces absorb most of the sunlight that falls on them instead of reflecting it, converting that light into heat. A shiny or light pot would bounce much of the energy away, so food would heat far more slowly.
How long does food take in a solar cooker?
A box cooker usually takes about one and a half to several hours, depending on sunlight, season and food type. Rice or dal often cooks in two to three hours around midday. Parabolic cookers work much faster, closer to a gas stove.
What are the main types of solar cookers?
The three main types are box cookers, panel cookers and parabolic or concentrating cookers. Box cookers trap heat in an insulated box, panel cookers use folding reflectors around a bagged pot, and parabolic cookers focus sunlight onto a single hot spot.

Part of the guide: Food & Kitchen Science →