In 2010, I wrote "How to build a Tracking Parabolic Solar Collector" describing my self designed and built working prototype and test results. I tried to show what a determined person can do with ordinary tools and materials, a good hardware store and a bit of perseverance - a high performance Do It Yourself (DIY) solar heater.
Since then, I have had lots of great feedback from the 600+ people who bought the book and Thank You for that!
[updated March 2014] Over the past four years, I have improved the design. This improved design is described in detail my new book "Solar Parabolic Trough Concentrator: Home Experimenter's Manual".
The reflector design has been simplified. I have done a series of measurements and started working with glass evacuated tubes as insulators for the solar collector to enable higher temperatures and winter use.
Gen2 design goals:
Simpler hand or machine made ribs In the original version, there were three different types of ribs - now one rib does all three jobs. The new rib is simpler and lighter. Thirteen can be made from a 2x4' (30x60 cm) sheet of material, only seven of the original could be made from a sheet this size. The ends of the rib are simplified to suit angle profile side channels which should be available anywhere.
I show the methods I use to make small quantities by hand using patterns. I provide .dwg files for CNC laser or water cutting for larger quantity production.
(click any pic to enlarge)
Simpler side channels I show how to use a standard angle profile in a very strong and precise joint that can be made by hand or machine. Different materials can be used, to suit what is locally available. The resulting reflector assembly is robust yet light weight and completely grips the reflective sheet along the long edge and supports it accurately from below.
Better balance, more efficient Each reflector assembly is balanced before installation. Balancing ensures that minimal force and therefore energy is required to position the array. In this way, different material can be used and the assembly adjusted just once for any resulting balance shift. I think I should be able to swing up to 25 reflectors with the existing motor drive with this new method.
Insulated, high temperature collector option I show how to suspend a standard glass evacuated tube at the focus and use it as a large thermos bottle to surround the collector. Higher temperatures and or winter use are thus made possible with this design.
A ball bearing support and a much stiffer reflector frame will make high altitude use possible (near vertical mounting). You can use this either insulated or not.
Flexible size I will show you how to make several different sizes of collector. All are based on the same parts.
You can make this in your garage You need some basic woodworking tools. I have improved some of the methods. It will take less time to make.
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The index at the top of this page takes you to articles on this blog about gen2.
Thanks as always for your feedback and Thank You for your interest.
Lion's Head, Ontario