This article is a guide to building your own umbrella solar cooker. To learn more about solar cookers and what they do, read this article: SOLAR COOKERS: AN INTRODUCTION.
This is the third, and probably most creative, segment of our DIY solar cooker series- how to make a solar cooker out of an umbrella.
This cooker utilizes the parabola shape, one of the most effective shapes for solar reflectors. The reason for this is, because of its bowl shape, it takes different streams of sunlight and directs them onto one point.
The traditional downside to parabola-shaped solar reflectors, though, is that they’re hard to make, and they’re hard to store and transfer. The umbrella model solves this- It’s already in the right shape, and you can open and close it like a regular umbrella, so it’s very easy to store.
WHAT YOU’LL NEED:
1) An umbrella with a diameter of 120 cm or greater.
2) Aluminum foil
4) A metal saw
5) A drill
6) Measuring tape
7) A paint brush with a thin handle
8 ) Scissors
9) A permanent marker
10) A tripod for flower pots, a few inches in height.
11) A dark cooking pot
PUTTING IT TOGETHER
1) Applying the Foil
Open the umbrella, and glue the foil onto the inside. Apply with the shiny side facing out, and apply it like you would wallpaper- tight and smooth. Try and follow the folds of the umbrella, to most naturally fit its form.
You’ll want it so the foil keeps its form even when you close the umbrella. Cover all of the inner umbrella with foil.
2) Losing Your Handle
You know the plastic piece that slides up and down the handle, and clicks into place at the top? With your umbrella fully open, drill a hole through this piece, and the metal handle beneath it. Insert your brush into this hole, to hold the umbrella open. Then, saw off the metal handle, just below the plastic slider piece.
3) Setting up Your Tripod
Place your tripod over the center of the inside of your umbrella. mark where the legs sit with your marker. Remover the tripod, and cut holes in these spots for the legs to fit though.
COOKING WITH YOUR UMBRELLA SOLAR COOKER
To cook with your umbrella solar cooker:
1) Open your umbrella, and insert your pencil or pen into the handle to keep the umbrella open.
2) Place it on a flat, dry surface away from any shadows (or future shadows- your cooker will have to stay shadow-free for many hours).
3) To cook a meal for noon, have your cooker facing south east, and begin cooking between 9-10am.
To cook a meal for the evening, have your cooker face south west and begin cooking between 1-2pm.
For all day cooking, have your cooker face directly south.
4) Put your tripod into the center of your umbrella, with the legs sitting through the holes.
5) Put the food you want to cook into your dark cooking pot. Place the pot onto your tripod, with the sunlight directed into it. To increase the cooking temperature by 20 degrees or so, place your pot in a plastic oven bag.
6) When you’re finished cooking, remove the pot and tripod. Insert the umbrella handle back into the plastic slider thing. You can then slide the piece down, and close the umbrella the way you normally would.
For more information on building various other solar cookers, check out solarcooking.org, a phenomenal resource on the subject.
Good luck and stay prepared!