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Want collaborators for a solar hot water project Answered

I have had this idea for a while and I decided to try and make it a collaboration instead of just trying to do it by myself. I thought there was a way to start a collaborative instructable, but I don't see that option now. Does anyone out there know how to do a collaborative instructable? Maybe that option appears right before you publish it? I don't know if the best way to share ideas is this forum, or the collaborative instructable (if it exists).

Here is the idea:
I have a solar box cooker, which is shown in this instructable. On days when I have nothing to cook, I often put a kettle of water in it, so when I get home from work I have very hot water that can be used for cooking pasta, making  tea, coffee etc. I pour that water into a thermos, and it will stay hot until the next day.

I would like to design and build a solar cooker that is dedicated to this task with this tentative list of requirements:

*It would be fairly small, just large enough to hold a kettle
*It would be easy to put the kettle in and take it out
*It would be weatherproof, so it could sit outside for months at a time
*It would be designed in such a way that it would collect energy from the Sun during a large portion of the day, without need of any sun-tracking mechanism
*Ideally, it would have a mechanism that would transfer the water to a thermos as soon as it boiled, or got to a certain temperature.

Looking forward to hearing from people who want to collaborate on this. As soon as we have decided on where to share ideas, I'll post mine.



7 years ago

Sorry, but I won't collaborate, I do have ideas though. The mechanism would be fairly straightforward. When the water is already boiled, the water would tend to rise, so we could put a float in there. When it reaches a certain point, it opens a valve while simultaneously activating a spring-loaded locking mechanism to prevent it from moving any further. The valve will release the boiled water into a thermos. You can somehow adjust the spring-lock; the higher it is, the higher the temperature needed to trigger it. A compound parabolic heater is a good design since the tracking mechanism (maybe a water-clock to be simple) wouldn't need fine adjustment if it is used. The compound parabolic design can maintain a hot-spot for hours at a time without the need to re-adjust, so might as well use no sun-tracking mechanism in the first place. It could be fairly small, depending on several conditions. The kettle is located underneath the compound parabola so removal is easier than eating pie (serious, it takes time). Done! Improve as you wish.


8 years ago

For your project: There are roof-top passive solar heaters that are worth studying for design ideas. Most are basically glass tubes ~6" dia. by 6' long. The tubes fill with water from bottom and heated water flows out the top. Immersed in the tubes are green metal fins or tubes that absorb sunlight, thus conducting the heat-energy to the water. Work really good, you can get ~150 degree water from them.

Add a solar oven-trough and you could boil.  Be careful with steam however, tricky.  Explosions can be frequent and very dangerous.


8 years ago

The only thing is the reflector. Most super shiny materials break down in UV light (mylar, tin foil, etc.)

How hot do you really want the water? This will determine the specific design to a large extent.


8 years ago

i would be interested in collaborating with you on that project (well at least theoratical as i am a poor student living in germany)...
for collaborative instructables: when in the editing screen of your ible click on the [SHARE] tab and then on the [COLLABORATE] sub-tab...


Reply 8 years ago

Thank you. I hope to post the instructable soon and make it a collaboration. I don't think being a poor student will be an impediment to generating good ideas and I hope to design a device that is made of mostly recycled materials.