FULL VIDEO WITH MORE PICTURES: https://www.youtube.com/watch?v=euCJ44_tdqs
NOTE: This was built in 2006 with minimum components and searching around the for the best deals at the time. The copper was the most expensive component with $60 of copper. This is a DIY (do it yourself) solar thermal panel that made hot water for a farm. I built all components with my friend using all parts from Lowes/Home Depot/local hardware stores. Each challenge was to make the solar thermal panels under $100, which we successfully did for each panel. All components can be bought from stores, nothing was special order or special parts.
After hooking up the system for the summer of 2011, the system performed very well and actually produced 170 degree F water. The hot water was kept in a Rubbermaid bucket, but the plastic was so cheap that the hot water from the panel melted the Rubbermaid bucket you see in the one of the pictures. I created a thermosiphon, which means that I did not use any electric pumps to move the hot water. The flow rate is about 1 gallon per minute to 1.5 gallons per minute (GPM) when measured inside of the hot water tubing.
There are no tubes inside the barrel. I used hose connectors through the side of the barrel with silicone glue. They are like garden hose valves/connectors that you can find in Lowes/Home Depot. I am using CPVC because garden hose and regular PVC melt at the high temperatures. I was getting 190 degree F temperatures in February with this configuration. Below 55 F, the unit is still producing hot water at 150 F or higher.
Also, I would recommend that you have a drainback system for during the day so that if you are using straight water it does not freeze or burst your piping. If you are trying to heat something else, I would recommend using a heat exchanger type of system, where there are separate tubes in your bucket. This is so you can use antifreeze in your solar flat plate collector. The antifreeze will heat up the tubes running through the barrel. I am writing a book now on how to build this set up for under $100. I put about 48 hours into this project in research, buying the parts, and actually building it.
The project was successful in that it helped warm a barn and a bed of worms. I will upload more videos soon of the DIY solar thermal panel. Feel free to send me a message or leave a comment if you have any questions.
My other video, which was my first DIY solar thermal panel, can be watched at: http://www.youtube.com/watch?v=XpZxAZoccVk
Here is my DIY Solar and Wind book that was published on Amazon: http://www.amazon.com/gp/product/1508454310/ref=as_li_tl?ie=UTF8&camp=1789&creative=390957&creativeASIN=1508454310&linkCode=as2&tag=erilaysyoucha-20&linkId=URNF3DPORKY4M5YR
Barnes and Noble Nook version of my DIY Solar and Wind Book:
This book is one of my favorite solar books in my library (bought it on Amazon) and I can recommend many of the solar books on Amazon to help learn more about solar energy:
This Grape 100 Watt Solar panel on Amazon is very similar to the panel that was bought at Home Depot: