Solar Cooking
Last edited: 12 April 2022      

An example of a manufactured improved combustion Rocket Stove

Comparison with a 3-stone fire - Dieter Seifert

This photo illustrates the amount of fuel needed using a traditional three-stone fire (left) compared to a Ben 2 improved-combustion stove (right).

Improved combustion stoves can be valuable companions to solar cookers as part of the Integrated Cooking Method. Some can be easily constructed from low-cost materials such as bricks and concrete blocks, while other designs are offered as finished manufactured stoves.

They burn small pieces of wood or other biomass very efficiently, greatly reducing the amount of fuel required. The fire burns very hot, which eliminates much of the smoke typical of open fires.

Although the level of smoke produced is reduced, there is still a risk of respiratory illness when used indoors, or with the constant attention required to feed more fuel to the stove.

Gasifiers are versions of improved combustion stoves that are designed to burn the gases given off from biomass fuel in a low oxygen environment, without actually burning the fuel itself. This is the process used to make charcoal. Gasifier stoves have an inner chamber with the fuel, and an outer chamber with venting to provide combustion air for the burning of the gases released from the fuel, typically near the top of the stove.

The advantages of gasifier stoves include economic fuel consumption and low carbon monoxide (CO) and particulate emissions. Disadvantages can include the necessity of having a uniformly dried fuel source (possibly biomass pellets or briquettes), and the inability to add more fuel during the cooking cycle. Windy conditions can create problems with maintaining an even draft through the stove. Bernhard Müller has written an excellent explanation of how gasifier stoves work and are constructed. See: Gasifiers


  • 25-27 January 2019 (Kirkland, Washington, USA): (ETHOS) Cookstoves Conference 2019 - Engineers in Technical and Humanitarian Opportunities of Service. More information...
Ben 2 Nepal 2015e

The Ben 2 Firewood Stove

  • May 2015: Dieter Seifert reports: Today I have made tests with the Ben 2 and Ben 3 Firewood Stoves. It is almost unbelievable, but the efficiency is always higher than 40% and if one does not heat up too fast (i.e., the power under 1.5 kW is), the result is almost no smoke and approximately 350 g thin wooden sticks can bring 6 liters of water to a boil in 25 minutes. Of course cooking is much more convenient with a large parabolic solar cooker (We have used the AlSol 1.4 for many years.). The Ben ovens are so easy to prepare (2 sheets provided with holes and bending, drilling a ring and three legs and turn, turn 4 bars hairpin-shaped and assemble everything) that the cost in firewood crisis regions would be well below $10 USD. The combination of heat-retention cooking and improved combustion stoves with the solar cooker is ideal. The solar cooker can do much more than just cooking. It is a peace-creating technology that is so urgently needed.
Joshua Guinto solar dryer, bio-char diagram, 12-11-14

Diagram showing the role the solar dryer plays in helping produce dried fruits, vegetables, and briquettes for fuel-efficient cookstoves.

Articles in the media[]


Construction plans[]

See also the other construction videos listed below:

Audio and video[]


The "4 Block" Rocket Stove! - DIY Rocket Stove - (Concrete Cinder Block Rocket Stove) - Simple DIY


Rocket Stove Ideas 33 - Brick Box Rocket Stove

Pekka Leskela explains how his brick Rocket style stove works and is assembled.


Clean Cooking Stoves for Vietnamese farmers - November 2012

Vietnam Solar Serve has designed their version of a double-wall stove that allows for a secondary burn, which allows for more complete combustion and creates more heat.


See also[]

External links[]

Clean Cooking Alliance site:

Aprovecho site:

Capturing Heat - Aprovecho

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