The Parapanel Solar Cooker

PRECAUTIONS.

SUPERVISE children and vulnerable people please when doing solar activities. The following precautions apply to anybody who is close to the action.

Remember that you may be watching the action, specially when you first use a solar cooker, so you might be exposed to the sun for longer than normal.

PROTECT EYES:The reflection of the sun can burn eyes very quickly. This is most noticeable if your eye is near the focal point of a curved reflector. So do not look at the reflector directly or even in a mirror, Wear sunglasses and cast your shadow over the reflector when adjusting or inspecting the pot.

PROTECT HANDS: The cooking pots get very hot. I suggest using heatproof(eg oven gloves or mitts).

PROTECT HEAD: Remember to wear a hat to shade your head, specially if you have short or sparse hair.

PROTECT SKIN: Wear long sleeves. trouser legs and high necklines. Use sunblock sunscreen.

INTRODUCTION:
There are many people all over the world who cook solar. It is possible to cook in the UK just using the power of the sun even in midwinter. On a clear Spring/Summer/Autumn day we receive about 1Kw of energy per square metre of the earth’s surface. It’s less in Winter, but still usable. We know how hot a car gets if it’s parked in the sun. If we use a lens or mirrors we can focus this on a smaller area and increase the heating effect. These can melt steel if well designed! I don’t suggest you try that, but a home-made cooker is a safe thing to build, providing you remember that THE POT GETS HOT. The cooker itself does not. So use gloves or a thick cloth when handling the pot. I designed and built the cooker described here in 2017. It produces about 500 watts; compare that to an electric slow cooker that uses under 200 or an electric oven that uses 1Kw. It is built using cardboard, duck tape, glue, string and a shiny material – mylar(emergency/space blanket) or aluminium foil(you can even use foil that has been used to wrap a roast if you wash it and flatten out the crinkles). The pot can be a used food tin painted black on the outside and put on a trivet . The ‘oven’ can be an upturned pyrex or clear plastic bowl. It can be placed on the ground or on a table as it doesn’t get hot; It is used to reduce heat loss from convection. Some people even put the whole thing on a table indoors next to a window: I haven’t tried that as our home doesn’t have south-facing windows with table- space under them. I made a very simple lightweight trestle table. You cannot use this cooker to fry, the maximum temperature I have recorded is 245 Fahrenheit(118 Centigrade). Cooking times are longer than electric or gas but this can be better for the flavour and texture of the food. There are plenty of recipes online.

I have used metric and Imperial measurements due to my age!

The first picture is what it looks like in use.

I haven't included the list of ingredients as it is so versatile to make... you can use whatever is to hand. But I suggest a craft knife to cut the cardboard, duck tape and string, scissors to cut the reflective material. You can either use glue to hold the reflective foil onto the cardboard or sticky tape to hold the edges in place

All the details of making it, including how to create the parabola are in the pdf included in this instructable. I intended it to be on my own website, but have now decided to add it to the Instructables library. I will try to answer any questions you have.

Enjoy the 'Make'n'cook' experience

Dave