Ray Wells says:

A quick Google Shopping search turns up oven thermometers for as little as $1.88. Hopefully that wouldn’t put the base price up too high. I would think that large-scale production would allow the producer to get the thermometers for under $1.00 each.

It has been my experience with another solar oven that an oven thermometer inside can be difficult to read, because of condensation on the top of the oven.

Thanks for the nice writeup, Brian. The Kyoto Box is a combination of de Sausseurs “hot box” from 1767 and modern manufacturing (cardboard, from ca. 1880!). However, the production version is made from recycled polypropylene and will last much longer. PP only consists of carbon and hydrogen and is completely benign.

Yes we will include a thermometer, and it can be made for a lot less than a buck – we just use thermographic plastic indicators (like the babyspoons that change color when the food is too hot). We will have three indicators – one for reaching pasteurization (68C), one for food cooking (85C) and one for seeing when the food is still too hot for being infected by bacteria (45C). Each has its own color, so it will be easy to see through the glass. As the sun sets, you can close down the lids and keep the food warm until everybody comes home from work.

We are also working on some add-ons for cooling and desalination.