In early spring of 2008 I started a new version of a solar oven. The design is a combination of a simple box oven with reflectors and a parabolic mirror concentrator providing additional sunlight at the bottom. The photo above shows the oven as it was originally built. As I used the oven, I found that there was a possibility of burning the bottom of the oven wood frame. If the parabolic mirror was not adjusted properly, or if the angle of the sun changed during the cooking time, the focal point of the band of concentrated light would be on an area of wood, and eventually would scorch the wood, almost to the point of catching fire. The final version of the oven was built without the parabolic mirror concentrator, and the interior was rebuilt using aluminum printing plates and a fiberglass insulation rather than polystyrene sheets. As you can see the interior foam insulation had deteriorated and started to melt from the high temperatures. I had been averaging about 275 to 300 degrees. Some of the construction details are outlined in the following series of photos.The new version is currently being used by Urban Harvest of Houston, TX. www.urbanharvest.org. A full set of plans - or a complete oven can be ordered from www.homesteadservices.org

Interior photo showing melted polystyrene foam insulation board.

Photo showing the burned area.