Sol Invictus...Might as well be cooking with the sun.

Free cooking. No moving parts.  No fossil fuel. No utility bill. Built with recycled parts.

I've spent the past few days turning a bunch of recycled odds-and-ends  into a solar oven. The summer heat has made cooking inside uncomfortable and expensive. We heat up the house with the oven or stove (which uses electricity) then We have to turn down the thermostat to cool the house (using more electricity).

Sol Invictus A.k.a Sunny Boy

The oven was designed around, and built from, things I had laying around. The full out-of-pocket cost was about $40. This was mostly for a piece of tempered glass and some hardware.

Ready for the first test run. The reflector is temporary and will be replaced by 4 reflectors covered in chrome sign grade vinyl. The door is an old picture frame holding a sheet of 1/4" tempered glass.

The oven is a metal box inside an insulated outer box made from a half sheet of plywood that was left over from another project.

Humble beginnings:

 This old heavy metal parts bin is just the right size for the oven. It also has a nice rim to hold  a gasket. It's heavy gauge steel and should store the heat well.

I cut the triangular shapes out, bent the lip back against the box and welded a filler piece in to make it rectangular.

I made a plywood box 2" larger than the metal box all around.

This old  broiler pan will become "The Levelator"

Sliced and diced

"The Levelator" keeps the cooking surface level as the oven is angled into the sun and raised or lowered.

Painted with high-temp black to convert the sunlight to heat.

The space between the inner and outer box is stuffed with recycled fiber insulation from insulated candy shipping boxes. The metal box was wrapped with foil prior to insulating. This will reflect some heat back into the cooking chamber.

An old picture frame holds the tempered glass and allows you to see a "Picture" of your lunch.

The reflector is temporary. It will have 4 reflectors set at a 60degree angle to the box. They will funnel more sunlight into the oven.

First test today was a great success despite a hazy, partly cloudy day, and having just one reflector.

 I pointed it at the sun at 10:00am and  it reached 325f .within an hour. Clouds drifting in front of the sun and a light intermittent shower did little to cool it off. It ran between 275f. and 325f.  until a sudden thunderstorm drove us into the garage about 4:30pm. Two hours later it was still showing 170f. in the garage. I expect the heavy gauge metal helped keep the temp pretty constant all day.

TIME TO COOK SOMETHING