Building a parabolic solar oven really isn’t as difficult as it may seem, once the basics are first understood.
There are many popular solar cookers in use today, including the Sun Oven, Sports Solar Oven, and the Cookit, to name but a few. However they all adopt either the box or trough design. Very few designs are actually parabolic, those that are, are generally quite expensive like the SK-14, compared to the more popular designs. The box solar cooker for example, is simply a cardboard box with reflective panels and a pane of glass which traps hot air in a box.
So what is a parabolic solar oven?
The sun’s rays are collected using a reflective surface like a parabola or curved surface. The main difference between a parabolic solar oven and other solar cooker designs is that the parabolic shape focusses the sun’s rays into one point; called the focal point. A small focal point means a greater concentration of solar energy. With a parabolic solar oven, it is possible to cook food at the same rate that food is cooked in a conventional oven.
Parabolic solar cookers are considered to be a better alternative for outdoor cooking and camping as they require no firewood or the need for gas stoves and they offer fast cooking times.
Why build a parabolic solar oven?
Building a parabolic solar oven will result in a higher power output than other solar cooker design. Remember, the smaller the focal point, the higher the cooking temperature. Water can be boiled in seconds using a sufficient sized parabolic cooker. However, due to the high level of accuracy required in the manufacture of parabolic cookers, a minimal focal point is very difficult to obtain.
Very high cooking temperatures can be obtained with a parabolic solar cooker, thus drastically reducing the time taken to cook food and to boil water. The box design solar cookers generally take several hours to cook food.
To summarise, building a parabolic solar cooker offers faster cooking times than other more conventional solar cooker designs. However, please bear in mind that parabolas need more frequent adjusting, pointing to the sun to optimize cooking with the sun.
How do I build a parabolic solar oven?…
Several methods are available, one easy and ready-made solution is to use a satellite dish. Then line the inside of the dish with a reflective material such as aluminium foil, or better still Mylar. Anodized aluminium could be used, even small segments of mirror. However, the focal point would become ’scattered’ as the mirror and anodized ally would not give a true parabolic shape.
After researching and testing countless parabolic and general solar cooking designs, the following conclusions have been made: -
First of all, work out what size parabola you want to build. As a rule of thumb, every one square metre of reflective surface equates to 1kw of solar energy. This isn’t quite the case for a paraboloid due to its shape, but the rule will suffice. A one metre diameter parabolic which has been engineered to a high spec will pump out more than enough heat to boil water in a few minutes. The SolaReflex 2500 reported temperatures in excess of 2,500F! The Solarflex was not been designed for solar cooking because it could melt aluminium, copper and brass. Their website states that it was designed for scientific/industrial/educational use only.
800Watts or more of solar energy is sufficient for cooking your solar food.
Establish a focal point. Let’s assume you 
are building a one metre dish. A suitable focal point would be approximately 20cm as in Figure 1.
Figure 2 shows a focal point of 25cm which wouldn’t produce the same results as the focal point of 20cm. 
This is due to factors such as wind, stand design, and cooling effects. With the cooking vessel situated at a focal point of approximately a third of the way down from the top of parabola, this will ensure sufficient wind protection, as well as an area where the heat is ‘captured’ and retained.
The picture at the top of this post shows one of my earlier parabolic solar cooker designs. Note the depth of the cooking pot, in relation to the actual dish. This oven reached temperatures in excess of 300F (80cm diameter). My current design is lighter (easy to carry in any backpack), sturdier and more powerful.
For more information on building a parabolic solar cooker, visit parabolic cooker kits section
It is also important to choose the right cooking pot for the cooker. It has to be dark in colour and placed in the correct position, namely in the middle of the focal point. It also needs to be oriented to the sun and placed on a small stand that sits at the point of focus for the oven. Parabolic solar cookers can work for 60 to 90 minutes unattended. If you find that the food is not cooked or that another pot has to be heated, then simply adjust the dish to point to the sun every 15-20 minutes or so.
One final note, if the focal point is too low or too shallow, i.e. a very deep parabola as in 
Figure 3, then the sun rays will ‘bounce’ on the top and sides of the cooking vessel, and not from underneath as they should do. It is also very difficult to manufacture – ref incorporating stand with a deep shaped dish. There is also a smaller surface area, in that the sun’s rays only penetrate whatever diameter the dish is set to, irrespective of depth.
Figure 4 shows the opposite of a deep parabola
. This design is workable, providing a relatively large diameter dish is used. Factors such as the wind and insulation of cooking vessel must be taken into account for this audacious design. Many satellite dishes have a focal point just outside the depth of the dish. This is due to ease of manufacture and optimal threshold for capturing frequency bands.
Suitable materials for building a parabolic solar cooker.
- Reflective mirrors
- Finished anodised aluminium (quite expensive).
- Mylar - used in hydroponic set ups, creases and tares quite easily but very economic and approximately 95-98% reflectivity.
- Aluminium foil - cheap and cheerful, however creases and tares can play a large part in the build. Foil is a great starting point as it’s cheap and readily available.
- Reflective vinyl, highly reflective material which also comes with an adhesive backing. For more details visit build your own solar cooker section.
So now you have a good understanding of what a parabolic cooker is and the main concepts needed to start building your very own parabolic solar cooker. So, what are you waiting for… 
Happy building.
I will happily include any photos you submit of your parabolic solar cooker for fellow readers to enjoy, learn and share tips and tricks about the wonderful world of solar cooking. Email your photos.
Here are some great links which are plentiful in their offerings on building a parabolic solar cooker:
www.solreka.com/products/solar-cookers
General introduction to Solar Cooking
Instructions for building a parabolic solar cooker
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Tags: alternative | build | how to | oven | parabolic | solar | Solar Cooking
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25 Responses to “How to Build a Parabolic Solar Cooker”
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July 2nd, 2008 at 1:52 am
I really enjoyed your article Rob. I look forward to its release. If I remember correctly I believe you estimated the temperature at the focal point of the 80mm to be slightly more than 300 degrees Fahrenheit? i may have gotten that wrong….Vern
July 2nd, 2008 at 12:22 pm
Vern,
Many thanks for those kind words.
You are correct, temperatures in excess of 300F have been obtained with the 80cm diameter dish. Please note that the results were recorded in England (weather - occasional cloud cover, temp average 22C)
I can only dream of seeing higher temps in other, warmer climates.
I look forward to receiving reports from SolReka users from from off lands where temps typically reach the high 20’s, low 30’s.
Larger dishes will become available, and customers will have the chance to order bespoke (any-size) parabolic dishes. However, I must currently focus my efforts on bringing the 80cm to market, subsequent parabolas will follow soon afterwards.
Regards
Sol
July 4th, 2008 at 1:53 pm
although I cannot fully appreciate the way the cooker is going to be built, you’ve got me interested such that I’ll probably ask my daughter to build one for me. thanks for sharing.
July 5th, 2008 at 9:27 pm
Hi Jane
I’m glad to hear that you are going to have a go at building the parabolic solar oven with your daughter.
What a great way to learn all about about solar cooking by sharing your ideas, thoughts and experiences with your daughter.
I would love to know how you get on, I will be more than happy to post a photo of your parabolic solar oven on my blog.
Let us know if you have any more questions. I will be only too happy to help.
Regards
Sol
July 6th, 2008 at 6:54 pm
Thanks so much for sharing all this information. Sounds like a great thing for camping. Can’t wait to try one out.
Dagny
http://www.onnotextiles.com
organic apparel
July 7th, 2008 at 1:14 pm
Super article Rob. Parabolic cookers definitely qualify as dorkage. I’m gonna see about building something like this. I built an “oven” when I was in Costa Rica, consisting of reflective panels which I set up around my hotplate, then my only cooking implement. I set up a rack over the hot plate and put the scones on it. It worked pretty well all things considered.
July 10th, 2008 at 5:59 pm
I love solar products but I have not seen one of these since I was a kid. We use to play with a 12-16″ dish to heat food. Once I finish my composting project this looks like a perfect project!
Green Authors’s last blog post..Unisolar 64 Watt Thinfilm Panel: RV Solar Installation | Renewable Energy Resources
July 10th, 2008 at 8:33 pm
How to build a parabolic solar oven | SolReka - Solar Cooking and Alternative Energy News…
A guide showing you how to build a parabolic solar cooker. Other designs also available including the pizza box and cone solar cooker.
SolReka…
July 10th, 2008 at 8:36 pm
@Green Authors
Great website you have, a digg site for all things relating to alternative power - nice
I wrote an article regarding the building of a parabolic oven and posted it on your website
Many thanks for dropping by.
July 13th, 2008 at 6:23 pm
How to build a parabolic solar oven…
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July 27th, 2008 at 1:19 pm
I have seen your interesting note on solar oven;it must be very efficient;but how much does it cost?; there are a number of interesting models like yours;their main disadvantage for use by the poor in countries like India and Africa is their cost; I designed a solar cooker with a semi- paraboloid shaped bamboo basket[available locally in most Indian rural and forest villages] for Rs.40[80 cents]; for the reflecting surface I used locally available ‘eating plates’-these are paper plates of 15′ diameter coated with a thin foil of Aluminum or a silver colored polythene film-;each cost Rs.1.25[2 cents!] ;five or six of them will be adequate;in all the cost does not exceed one dollar;it cooked rice in two hours;the cooking time can be brought down by fine tuning;the rice was put in a Aluminum vessel enclosed in a black polythene bag or in a glass vessel;the glass vessel was quicker in cooking. i wil send some photos by next post.
RKRAO
July 27th, 2008 at 11:06 pm
@RKRAO
Hi Krishna
Great feedback on your solar cooker, it just goes to show how cost effective solar ovens can be.
I wish you the best of luck with your venture.
May I post your pictures of your solar oven on my blog, I’m sure fellow readers would love to see your oven in action.
Regards
Rob
July 28th, 2008 at 7:38 pm
[…] The bamboo solar cooker is a simpler version to that of the parabolic solar cooker. […]
July 29th, 2008 at 12:39 pm
We want to give this as a project to 10th std. students of our Lions School,situated in Raichur,Karnataka,INDIA.
July 29th, 2008 at 10:47 pm
asok patil can contact me at rkraoifs@yahoo.com if any help is needed besides what was given on this website;the students should read the note given here to locate the crucial focal point; a one meter diameter bamboo basket wowld be adequate under the indian sun.
rkrao
August 23rd, 2008 at 9:13 am
Hmmm…it doesn’t look easy to me but I think there’s no harm in trying to see how it goes. Maybe I’ll take it up as a project and get few of my friends to help me on this. It interests me because I’ve seen other similar models before and I’m sure this one is quite similar.
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August 24th, 2008 at 3:45 pm
@Sock Yee
I am currently compiling an ebook which will show you how to build a parabolic solar cooker.
Stay tuned
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September 26th, 2008 at 12:07 am
[…] http://solreka.com/blog/solar-cooking/ho…Hope that helps, good luck. Posted by Brad on September 25th, 2008 | Filed in Engineering | […]
September 26th, 2008 at 12:20 am
is it possible to get a reflective parabola to boil water to make steam enough to power a turbine/dynamo thing to make electricity? - as far as i know all of the forms of energy we use to get electricity are still just heat sources used to make steam (even nuclear) - i live in australia so we have plenty of sun.
September 26th, 2008 at 2:26 pm
Hi Gabe
Sure thing, I’m very close to finishing my website. Part of the product offerings include ebooks which show you how to build your very own highly accurate and powerful parabolic solar cooker, as well as self-build parabolic kits.
So keep watching this space in readiness for the launch of my website.
SolReka’s last blog post..Project Bluebeam - Holographic alien invasion
September 29th, 2008 at 12:45 am
what sort of turbine system would you recommend for a large parabolic dish say i.5metre diameter? how much electricity could be produced?
September 29th, 2008 at 6:06 pm
Hi gabe
I’m afraid I cannot answer that question for you. Suffice to say a 5m parabolic is massive in both size and power output.
For every 1 square metre of sunlight you can expect to produce approximately 1kW of energy. So a minimum of 5kW cou ld be anticipated for a 5m dish.
Perhaps a Stirling engine array would be a more suitable application for such a dish.
I hope this has helped somewhat.
SolReka’s last blog post..Project Bluebeam - Holographic alien invasion
October 15th, 2008 at 12:05 am
To read more information on making a parabolic solar cooker, please visit SolReka’s brand new website; http://www.solreka.com.
Here you will find information you need for building your very own fast, portable, and efficient solar cooker.
Regards
SolReka
Brighter Energy Solutions
SolReka’s last blog post..SolReka Website Launch
October 22nd, 2008 at 5:31 am
Great work!!!
We should be grateful to you for your efforts in educating us in alternative energy.
Thanks friend…
October 22nd, 2008 at 8:28 pm
Hi Harish
Many thanks for those kind words. I can’t wait to share with you the wonderful world of spinning neo magnets.