Solar Cooking
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Last edited: 15 May 2020      

The Heliac Solar Cooker fresnel lens concentrates solar energy onto a mirror, which refocusses it up to the bottom of the cooktop. - Photo credit: Heliac

Heliac is a company located in Hørsholm, Denmark. They produce polymer foil solar concentrators for medium size utility installations. They have developed a process to create a clear film with a profile that mimics the shape of traditional fresnel lens for a fraction of the cost.

They realized this technology would also be useful in creating a solar cooker design. The company claims this prototype is capable of boiling a liter of water in fifteen minutes. Having a simple framework, the company wishes others to build their own frames and use their material for the lens. They offer their design of the framework shown in photos as open source, and welcome interested parties to share their thoughts on the design and use of the cooker.

When mounted on a frame the solar cooker fresnel lens has an aperture area of 105cm x 140cm. The focal point has been purposely broadened, giving a spot size of 8cm in diameter. The focal length is 200cm, this being the distance the refracted rays travel before reaching the bottom of the pot.

The Heliac Solar Cooker v4.3 - Photo credit: Heliac

The instruction manuals for the most recent design of the framework (v4.3) can be accessed through the following links*

  • Production manual
  • Assembly manual
  • User manual

* Due to safety concerns we no longer recommend building the cooker in wood and are working on improving the design to meet our safety standards. As soon as the new design is ready, it will be possible to access the construction manuals.

Solar cooker features[]


  • January 2020: The SunStore Cooker was presented at CONSOLFOOD 2020 - Akiko Ishibashi
  • May 2019 A caution from the lens manufacturer: - Heliac is now recommending that the frameworks of solar cookers made with their lens, should be constructed of metal, not wood. They are so serious about this that they require the purchaser to sign a disclaimer. Not for unattended cooking. There have been instances of framework fires starting from misdirected lens.
  • November 2018: Heliac Solar Cooker earns the Judges' Choice Award in MIT Climate CoLab "Energy Supply 2018" contest - Judges agreed that solar cooking is an "exciting new approach to tackling climate change-from reducing emissions to shifting public perception to pricing carbon." The MIT Climate CoLab is an online crowdsourcing platform of over 100,000 global members, sourcing proposals on climate adaptation, reducing emissions from buildings and transport, behavioral change strategies, and more.

More information...

  • September 2017: Clement Musonda in Zambia constructs a Heliac Solar Cooker and tests it cooking various local meals.


Audio and video[]

  • February 2018:

Heliac Solar Cooker demonstration of use

Stefan Karnebäck describing how his own version of a Heliac solar cooker should be used and the requirements for making it perform optimally.


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Savsvinget 4D, DK-2970