Solar box cookers and solar panel cookers normally do not need to be turned to follow the sun unless you are cooking beans or an especially large amount of food. They may need to be moved once over a three or four hour cooking period. However, parabolic solar cookers require reorientation with the sun much more often. If tracking the sun is necessary, some of the ideas below will serve this purpose. Note that this page emphasized low-tech tracking methods that could be built with materials available in developing countries.
Scheffler Community Kitchen clockwork tracking systemEdit
Simply Solar provides explanation of their various tracking systems at Scheffler tracking systems. The mechanical system incorporates a clockwork mechanism, and often uses recycled bicycle parts. It is run by a weight and controlled by a pendulum. Resetting the reflector back from the evening position to the morning position is done by hand. They also offer photovoltaic options as well.
Programable tracking systemsEdit
Still in its infancy, programable tracking systems are being developed with software to not only rotate the reflector to maintain maximum exposure to the sun, but to also control cooking time and desired temperatures. One example of auto tracking and monitoring system is the SolarCue system, another is the Raspberry Pi: Solrmatic
Photovoltaic tracking systemsEdit
A clever system has been developed by several designers, which uses two photovoltaic panels configured to maintain an even balance of power to a small electrical turntable motor. The required photovoltaic panels typically are fairly small, and are placed side by side, but at slightly different angles to face the sun. As the sun moves across the sky one panel will begin to receive less direct sunlight.
The resulting electrical imbalance causes the dominant panel to engage the motor. The turntable will rotate until both photovoltaic panels face the sun equally, and the motor disengages. The simple system can be fairly lightweight for rotating a box or panel cooker. However, a larger parabolic solar cooker, which will benefit the most from a good tracking system, will require a stronger motor and larger panels to rotate the cooker.
Tracking for the HotPot solar cookerEdit
Most are familiar with the HotPot, a fine quality cooker. It does an excellent job of representing a solar cooker as a desirable appliance. However, the original design was created for use in tropical or semi-tropical areas bounded by the Tropic of Cancer and the Tropic of Capricorn (23.5°). The reflectors have been oriented for a more overhead sun position, which limit the cooking time in temperate locations to a 2 - 4 hour window. Here is an article that talks more about this issue. The author has been working on a tilting base mechanism to allow the reflectors to pick up early and late day sun. However, it may be a better idea to supplement the HotPot reflectors with a windshield shade tipped forward and wrapped behind the cooker to catch the early and late day sun, as the pot and glass enclosure are really not suited for non-level conditions. Details on this tracking design here.
Concepts for low-tech trackingEditSee Tracking Solar Accumulating Barbecue.
Audio and videoEdit
- December 2010: Programable system tracks the sun, and turns the reflector away when cooking is completed.
|March 2011: Box cooker rotated by PV panels sending power to 12 volt motor. As one PV panel begins to receive less light, it sends less power to the servo, which operates the motor until both panels are a sending balanced power stream.|
|April 2010: UC Berkeley student tracking system demonstration|
|March 2010: Tracking Solar Accumulating Barbecue - Brian White|
|May 2008: Clock based dripper tracker demo|
|June 2006: Dripper tracker for parabolic solar accumulator|
- Raspberry Pi: Solrmatic
- Scheffler Community Kitchen
- Sun Switch
- Tracking Solar Accumulating Barbecue
- Brian White
- Super Solar Tracker for Solar Ovens
- Solar calculations
- Redirecting Sunlight with Polar Tracking in Developing Countries… and Elsewhere - Pete Schwartz
- Cuisson Solaire Innovante: Mécanisme suivi de trajectoire solaire permettant le guidage d’une parabole - (English version)
- DIY photovoltaic solar tracking system
- Solar Water Boiler with Tracking System - Yousif Abakr
- Scheffler tracking systems
- Solar cooker research in Jordan
- Solar Tracking With A Box-Style Cooker - Jim Thomasson
- Readymade Solar Oven Trackers available for purchase at: www.solaroventrackers.com
- Solar Oven Trackers - Small Power Systems
- French: Pisteurs pour four solaire
- Appropedia heliostats article
- LightManufacturing Systems heliostats (commercial) and Solar Manufacturing systems