Solar Cooking
Last edited: 26 November 2019      

Solar Cooker Workgroup Sliedrecht (The Netherlands) provides free advice about producing and introducing the Dierkx type box cooker.

During its starting period the work group produced over 150 cookers in order to prove that cooking by sunrays would be possible. Since that time lots of experiments have been done and several projects with the cooker are going on now.

During this process an enormous amount of knowledge has been acquired. Apart from the Parabole Cooker and the Cookit the work group thinks cooking by sunrays with the Dierkx type Box Cooker (with its slanting window) the best way in most cases.

The services provided by the work group:

  • giving advice whether introduction is possible in a certain area;
  • providing drawings and advice about the various materials;
  • providing a folding device to make inner boxes;
  • providing a cooker for experimenting;
  • providing money for a project introducing the solar cooker;


  • March 2014: Solar Cooker Workgroup Sliedrecht is trying ​​new glazing for box cookers, the BC65 and 125 BC. Instead of glass, Mali cookers are equipped with film glazing. Initial reports are positive. The film is cheaper than glass. Gives less breakage in construction and during use. The film weighs almost nothing, so the cooker is now 8 to 10 kg lighter in weight. The film can be sent out more easily as glass. According to the manufacturer, it is 100% UV resistant. Solar Cooker Workgroup Sliedrecht has supported cooker workshops in Burkina Faso and Burundi.
  • August 2013: Solar Cooker Workgroup Sliedrecht (The Netherlands) has performed research for a new type of transparent cover. The aim was to replace the glass of the Dierkx type box cooker that the group is promoting. The main drawback of the glass is its weight. The focus of the research was on transparent foils and only one type of foil passed all tests. The workgroup has applied the selected foil to a first batch of solar cookers. In addition, the foil has been sent to a number of projects in Africa. The attachment of the foil to the wooden frame is still under investigation.
  • September 2012: During the past months the work group has been busy with training people in building and introducing the Dierkx type box cookers, model BC 65 and BC 122. The cookers are built during workshops in Sliedrecht. This year a few projects will receive money to raise a micro credit to acquire box cookers. In the Hungarian village Gerde as a test a project is supported to provide a whole village with box cookers. For people in Holland who want to build there own box cooker to use it on camping trips for example, this year we have developed a do-it-yourself kit. The kit contains the inside en outside box, with an oven thermometer, and a DVD with instructions and drawings for completing the cooker at home.
  • February 2012: Solar Cooker Workgroup Sliedrecht receives a yearly donation from a recycle shop in Sliedrecht in order to build and promote solar cookers. The group is still promoting the Dierkx type box cooker. In our opinion it is the best type of box cooker, because it is less dependent on wind and sun compared to the CooKit. As compared to the parabolic systems, we think the cooker has an advantage, because there is no need to stay with the cooker while it's cooking. For refugee camps the CooKit is a good solution. We think the Dierkx cooker is the best solution in permanently colonized regions. In our workplace we offer workshops to people who want to produce and introduce box cookers anywhere in the world. First we help them starting the project by providing those who have attended our workshop with money and materials to build 5 box cookers. Whenever we receive a positive response and when people seem to be willing to cook with the help of the sun, in the second phase we help them by providing money for building another 10 cookers. After that we judge if the project can be continued autonomously. An important condition for the help given by the work group is that during the manufacturing of the box cooker and the use of it, there must be a possibility of daily e-mail contact. Questions will be answered within 24 hours.
  • July 2007: In partnership with Solar Cooker Workgroup Sliedrecht, Solar Serve (SLS) has developed a new solar box cooker for use in Vietnam. The previous SLS solar box cooker is made from wood, which is increasing difficult to purchase in Vietnam. The new cooker is made from aluminum sheets that are shaped using two molds, one for the inner box and one for the outer box.
  • March 2006: Mr. Vazja Racvieshvili spent a week in the Netherlands with work group learning to construct an expanded Dierx-type solar box cooker. The cooker — dubbed the BC.122 — is 122 centimeters wide, making economical use of plywood sheets of the same width. During summer tests, the cooker reached temperatures of 175°C. With tools and funds from the work group, Mr. Racvieshvili will set up a small workshop in his village of Gurdzhaani. He believes that solar cookers can help reduce the cost of living in Georgia, a country with high unemployment.

Audio and video[]

  • November 2019: 

See more information on the Dierkx solar box cooker.

See also[]


Arie De Ruiter
Solar Cooker Workgroup Sliedrecht NL
Riverdijk 721
3361 BT Sliedrecht

Tel.: +31 184 421189
Fax: +31 184 417764


Website: (Dutch) (English)