"Kyoto Trough" solar cooker, will it catch on?

A couple of small points, could you learn how to activate your links, its simple, if you need help we can give you a couple of tips.

The video is (sorry) simply boring and far too long winded, you will lose a good deal of the interested people quite quickly or put them to sleep....

The instructable is basically not enough info to be called and "Instructable" its really only an idea for anyone to take and turn into something practical, if they wish!!

By the way, are you sure that the idea is even "new"?

The high sides mean that it will quickly go "off focus" as the sun moves, needing to be realigned relatively often as well......automatically readjustment would be good...a simple circuit with a PIC should do that.....

The twist to the parabolic trough gives it exactly 2 hours to go off focus. You can set up for different time periods if you choose. The webmaster on solarcooking.org asked me to add a piece about it to their wiki so I think it probably is new. He deals with solar cooking all over the world. I found and used free software to do the modeling. I have an instructable about that too. Feel free to improve it, it is a collaboration. "By the way, are you sure that the idea is even "new"?" There IS a guy who has done two parabolic troughs to do a point focus but he has been ignored for about 30 years. I try to do a pot focus instead. Thank you guys for recoiling so quickly.

Any good useful invention is 5% inspiration 95% transpiration.

The way I see it is, yesterday morning, you came up with this idea, modeled it on your computer (really poor model) and say you have figures to prove ... and whatever else.

What a turn off!

You just want other people to work on YOUR Baby. Shame on you.

Shame on you, yourself. I have been working on this for 2 years.

My bad.

Totally failed to notice your 2 years of effort.

Sorry.

There was NO free software method to do solar design before I started up the writeup to use art of illusion to do it in january this year. Did you know that? And that baby is on your doorstep too. The method is also released under a community commons licence.

Your "Joke" demeans you not me.

If you want to be productive, it is far better to join in than to do the grumpy old man stuff.

Are you sure that any useful invention is 5% inspiration and 95% transpiration?

Who are you to judge? I wrote up the model as quick as I could just in case I got hit by a car tomorrow.

Now, about peer review.

You can review my method, thats fair. And say it is crap. Fair enough.

But also you should be reviewing the idea, shouldn't you?

Did you do that?

Now about my "baby". I have abandoned it. Left it on your doorstep.

Are you going to kick it in the head?

Seems so.

I do not understand why I should pander to information junkies. If you want stuff done by reporters go to the science news sites. They might do something on this in 6 months or so.,

The point for me is to get this idea out into the world and show it to enough people so that someone somewhere tries it out.

For an amateur like me, doing full science is impossible. I would have to buy a parabolic dish and probes to test temperature, and tools to ensure that both dishes were alligned exactly. Then wait for a sunny day and take time off work. And then compare the trough design to it. So it is easier and more productive to release it under a community commons licence.

Which is what I did. So really the baby is in your care now.

You still keen on killing it?

Already apologized.

You right, I'm wrong.

Glad I made you think.

All of the best!

Hey Brian I would guess the major cost is the tempered glass. I am a bit surprised there is no frame to help protect the edges. For just a week old, not bad. Keep us updated on the innovations.

Brad

Are you thinking of something like this?

http://www.inhabitat.com/2008/03/17/world's-largest-solar-kitchen-in-india-can-cook-upto-38500-meals-per-day/

IF not sorry for the by line,

and good luck.

No, not really. Dishes are hard to make. Troughs are easy to make. The dishes shown need a fancy guidance system. Also, do any of you know what a stationary dish that collects all of the light that hits its surface over 2 hours and bounces it to the cooking pot will look like? It is not a parabolic dish, thats for sure. (When a parabolic dish is not pointed directly at the sun, much of the light misses the focus completely) I have a rough idea. It has 2 wings, and the sides of the wings are curved up to guide the light that hits left and right in towards the collector. The wings are wide at the tips and end up narrower near the cooking pot. They might even curve up and form a tube close to the cooking vessel to contain the light. These wings are alligned to the path of the sun. Now, compare that shape and the combined trough shape. Which will be easier to make in practice? Lots of people make fun of my modeling. Have any of you even tried to model a parabolic dish as the sun moves across the sky? Or a hemispherical dish?

There seems to be a trade off between a design that remains in focus vs one that does not. Your design does not require constant adjustment to keep it within the 'focus', but it does not use 100% of the light falling all the time. I've experimented with a solar 'trough' (glorified hot dog cooker), and noted that it takes some time to do the cooking even with a concentrated focus that a straight parabolic trough can provide.

I looked at your work on the 'instructables' work site; you've done quite a bit of work on this stuff. Have you worked on any "aiming" mechanisms for your panels?

I did a long reply that did not go through. Anyway, nothing will give 100% use of the light all of the time. What I am aiming for is 2,3 or 4 hours of ok 100% concentration on the cooking pot.

No current dish dilivers it because nobody has bothered design one!

http://www.youtube.com/watch?v=IIRhNRk_0js might help prove it.

I think my compound trough is the closest thing to it at the moment.

I think a dish design with 2 leaves in line with the path of the sun and with the outsides of the leaves curled up a bit will give best results.

Bit as I said, it hasn't been designed yet!

I made a tracking method that uses a clock motor. and floats and an equatorial mount and it is called a clock based dripper tracker. I have high hopes for it but nobody has shown much interest.

It is on the solar cooking wiki. (I won a science prize on instructables for it ) It needs 2 floats to be really effective.

Brian

Pardon me for being repetitive, but you're saying that all the reflected light for a two hour time period hits your 'cooking pot'?

Let's say for conversation sake it does. Then the 'cooking pot', or the focal target of your choosing, must be large enough to accommodate the shift in focus while the sun moves 30° across the sky in a two hour time frame.

I guess the problem I see is while the design may allow all the light to find the pot in the given time frame, it still may not be sufficiently concentrated to generate a high heat. Attempting to scale up the design would also result in a larger focal area (requiring a larger pot), and does not solve the problem.

Maybe I do not understand what the goal of design is. If you are trying to create a more low-tech approach to solar cooking, something that once fabricated would take little experience to use, and doesn't require fancy aiming gizmos, then in my opinion you've done well.

I have a video that explains it. http://www.youtube.com/watch?v=uX9Z-nsUHiA It is based on other peoples work. http://www.fossilfreedom.com/increase-output.html gives an idea (but I did not do it exactly the same way as they did). I assumed at the time that it applied to dishes as well as to troughs. It doesn't so it will be back to the drawing board to design a "Kyoto dish" Anyway the whole reason I looked at software for solar design is because I couldn't figure out on paper how the light bounces from a compound dish over time and I wanted to test the assumption. (I made the dish and it worked well but how can you know how good it really is?) And I wanted to prove to myself that the results of the video apply to dishes. Anyway, if you rotate the 2 halves of a parabolic trough inwards round the focus, line it up with the sun path and point it at the sun, all the light for that angle of sun movement, will pass behind where the focus was. That is where I stick the cooking pot. I use a red ball in the simulation because I am not much good with the software. If I could draw up a red pot, I would! The reason to use a red ball is because I put the camera high in the sky and fly it in the suns arc, and whatever red the camera sees on the trough or dish coresponds closely to the parts of the dish or trough that would reflect sunlight at those points in time. The guys at art of illusion have some different effects and ideas so that you could perhaps model 4 dishes or 4 troughs at one time in the one simulation! But that will come later if other people get interested. I know it is clunky and full of assumptions but really, what else is out there right now for doing this type of modeling? Brian

I checked out your video - nice work, I learned something. In my limited experimentation, I was trying to maximize the aperture distance in comparison to the amount of material needed to form the parabola (I have a limited amount of this material to work with - a 0.020 thick mirrored aluminum sheet). Of coarse, this approach pushes the focal point out, and there are the other trade-offs that go with it.

For my region, we might see a little over a 100W per square meter average maximum once the atmosphere is figured in, this is why I was looking at something with as much 'opening' to the sun as possible - figured I would need it to do any kind of heating at all. I like the compound designs, but it looks like it would take about 2.5x the amount of material with respect to the open end looking at the diagram on the site you listed.

As for software, I have access to AutoCad, but I don't know how to easily create a parabola. So my modeling is very slow...

Thank you. I think 100 watt per sq meter is really low. Is it always cloudy there? Here it is probably about 800 watt with clear skys. When you factor in losses, I think it ended up as only between 150 and 200 watts actually got transmitted to the stuff I was cooking last year. I thought that was truely horrible until I found results for a sk 14 parabolic dish in India. (It was better but also nearly twice as big as what I had). I cannot easily do a parabola either. but art of illusion offers a template option. You can find a parabola image that fits your computer screen, use that image as your template and Select 1 view and it appears in the background of your view of the scene. You can then zoom aoi till your parabola is a suitable size and just copy it with one of the curve options.

My 100W is just a best guess, and subject to the error that all guesses are. Looking at your instructable, your 'dish' appears to have around a square meter of exposure, perhaps a guess of 200W would be closer...

As for drawing the parabola, I found that AutoCad has a VBA interface, and I was programmatically able to more quickly draw a parabola of any focus and width - much faster than entering individual points. I'll see what I can do with compound parabolas.

Thank you very much. I expected lots of people would jump at the chance to try something new and I waited a couple of weeks before starting my trough. I have the big trough done and ran out of material. An 8 ft by 4 ft corrugated plastic sign is the big trough (About 1.5 sq meters of collector area and I will cover it with mylar or kitchen foil. I have to make the little parabola's for the final concentration of the light and will just use cardboard covered in kitchen foil for that. Should be fun. First pics are on instructables but no mylar reflective material is on yet. Brian

Your design sounds interesting.

When I did my little project, I encountered several problems during construction such as how to accurately cut a smooth edge for the reflecting surface, attaching the reflective material with distorting it, etc. I'll be curious to see the challenges you faced during your construction and how you solved them.

Let me know when your instructable is ready.

It will never be perfect but it is at http://www.instructables.com/id/Compound-solar-cooker/ and I will add to it every day or 2 as I have time and sun. Today I hope to add mylar to the trough, put on the little wings and mount it on something temporary. Brian

http://www.instructables.com/id/Compound-solar-cooker/ has link to a video of my first prototype. It is a temporary prototype so I did not glue anything down. It does seem to work as expected. It does 2 hours of cooking from a reflector that is about 1.2 sq meters. BUT I have had not yet had decent sun. It does seem to collect the sunlight in 2 planes like it should. I may redo it to be a 4 hour collector (It just means changing the curve on the large trough). I am wondering if anyone wants to try the concept on a panel cooker? Either a "long tail" panel cooker or one looking like the trough with 2 inward V wings at the sides? http://www.instructables.com/edit/preview?topicId=THRAQ7JFUPUPJRD hopefully explains it well enough. Brian

No current dish delivers it because nobody has bothered design one!

Though a correct statement it's off topic and inaccurate.

The thread is about a trough, right? Is apples to oranges if comparing the capability of a dish design to a troughs performance cycle

Basically the double wing design hinders efficiency compared to effective parabolic troughs

Perhaps you may find this document detailing analysis of a flat mirror V-trough including CONCENTRATORS, MIRRORS, OPTICAL MEASUREMENT, SOLAR COLLECTORS, ANNUAL VARIATIONS, ARRAYS, COMPUTER PROGRAMS, DESIGN ANALYSIS, GEOMETRY, OPTIMIZATION, SLOTS, SURFACE PROPERTIES on or about 1978 useful in your research.

No, my statement is not off topic at all. The kyoto trough is a solar cooker that combines troughs at right angles to each other to mimic how light would behave in a properly designed solar cooking DISH. A parabolic trough is only useful to cook hot dogs on spits or in large scale power plants to generate steam. The "wings" are necessary to concentrate light from the sides towards the middle where my cooking pot is. The trough is 4 ft wide and my pot is just 10 inches wide.

How would you get the four ft long focal line to concentrate on a 10 inch space?

Nobody has bothered to design the dish yet because only poor people cook with sun power.

This "market" has no money and starving people and their needs are not too high on the priority lists of designers.

The one I made trys to get all the suns rays to hit the cooking pot for a 2 hour period WITHOUT moving the dish. (It could be 3 or 4 hours without moving with a slight change to the curves).

If you "reverse engineer" (Mathematically) my 2 trough design, you will arrive at a really good dish shape that will diliver 2 hour solar cooking (without moving the dish).

(I cannot do the math myself but this is an engineering forum, isn't it?

Someone could do it if they wanted the challenge. Or if they wanted to help 3rd world devellopment without actually parting with money.

I do not know what this dish will look like. I think it will have 2 upward curved "leaves" to catch the sun.

That dish is the ideal situation. In the meantime, I will promote this idea. Making the dish that I describe is probably beyond the technology of poor people but perhaps making the combined trough "kyoto trough" is not. It just requires people to curve sheet material in one direction. It could be made to a template quite easily once material dimensions are known.

My research is done. It is up to others to run with it (or not).

I have seen resistance to ideas before and it is par for the course.

If you look at it with an open mind, it might make sense.

Brian

How would you get the four ft long focal line to concentrate on a 10 inch space?

With a Fresnel lens. You can capture as much or as little of the concentrated light as you want to.

Did you consider using the computer program developed in the Harvard study to do the math?

What fresnel lens are you talking about? Have you costed it out?

I bend a couple of bits of sheet material to a curve. It sounds a whole lot easier than making a fresnel lens from scratch, doens't it?

You linked to an abstract earlier. I did not know how to go further into the document.

I do not need to do the math.

Only if I do the dish will the math be necessary for me.

Ya know the stick on yer window see through image magnifiers they are a Fresnel lens too.

"Ya know the stick on yer window see through image magnifiers they are a Fresnel lens too" . Oh, so we have a joker. Well, they are good for burning spots on pieces of wood but as the sun moves across the sky, just a tiny bit, the focus moves and disintigrates. You do know that, don't you? Of course you do. So why did you post that nonsense? It is not fair.

I for one think the Author of the Post has a Great Idea and Applaud any efforts he is making in bringing his design to fruition.

Keep up the Green and Sustainable Work.

What is with all the Nay-Sayers? Are they working for the Fossil Fuel Companies and Big Business? Because truthfully 'we the people' that: breath air, drink water, and live from the plants that grow from the Earth (veggies and meat eaters) all need a pollution free alternatives to supplying all the products that we use in our daily lives. Do remember the web site you are on: The Sustainable Engineer Section: Sustainable to me means that: we are creating products that have minimal damage to the Environment.

I am starting to figure out that it will be the average person who is not affiliated with Big Business, Big Coal, and Big Oil companies that will make a difference in the Quest to Reduce Climate Change. It's painfully obvious that the Politicians in Office are not truly interested in becoming or making the USA a sustainable society.

I cover these and many other topics at: http://stlouisrenewableenergy.blogspot.com and welcome Guest Posts that relate to Green and Sustainable Lifestyle. Feel free to share your ideas and or comment on any of the posts. All I ask is that You Keep it Green.

Green Me UP-Scotty

Hi, green me up. I abandoned the kyoto trough idea. It might still be a good idea in the right hands but I couldn't figure out the correct angles or a way to find them.

But it was not a total waste of time for me. The idea is now "out there on the web" for others to work with if they want and It led to the solar design T-square and clam shaped solar cookers.

More work is required on that too but I have made a prototype clam shaped solar cooker and it worked as expected. Currently the pulser pump got nominated in a major competition (The ars electronica next idea competition in Linz Austria) so the solar stuff is on hold until they judge that.

People do fire a lot of negativity my way and I will acknowledge that I could do better.

BUT I feel that if I leave enough questions unanswered, other people will join in and confirm much of what I have done. This has not worked in the way that I expected. Ordinary people have joined in but the big organizations with massive brain and money resources (like engineers without borders and others) have bent over backwords looking for excuses to do nothing! I am starting to believe these organizations exist for the sole purpose of collecting donations.

gaiatechnician,

Like I said it will take people such as you and me to invent the next wheel or sustainable solar design.

I'm not an expert but am in the process of designing a Solar Trough for focused photovoltaic resources. From the preliminary design I believe I can produce as much electricity as 3-4 solar panels.

Which is how I found this site.

My head is spinning right now with all the Engineering computations and aspects for determining the electrical output of my model. My prior drafting skills used to determine weights and loads for designing buildings has not been much in helping. I do know there are computer programs out there to determine this and am fidling with a couple. The programs seem to be as difficult to understand as determining the original design.

So, I've decided to go public with my design with a public offering requesting assistance from copyright attys, engineers, and a manufacture assistance. My whole intentions are to make photovoltaic affordable for everyone.

I'll be posting info on the initial public offering at: http://stlouisrenewableenergy.blogspot.com or will have a link to a secure site for viewing the offering.

Keep at it, Never Give UP.

Green Me UP-Scotty

personal email available through the site. for continued conversation. Screw the clowns on here.