[[http://www.sunreign.com/info/ParabolicTrough Back to Parabolictrough.org Hompage.]]

=====Lets Build 'em !=====

""<img width='450' src='http://www.polskifiat.net/images/ORC.jpg' alt=''/><br>""

=====Open Top Design=====

[[http://www.sunreign.com/info/ParabolicTroughDIY001 Parabolictrough.org project version 1.]]
[[http://www.reuk.co.uk/Build-a-Concentrated-Solar-Water-Heater.htm Reuk.uk]]
[[http://www.iwilltry.org/b/projects/build-a-solar-hot-dog-cooker/ Parabolic HotDog Cooker]]
[[http://ktisis.cut.ac.cy/bitstream/10488/818/3/C1-Egypt.pdf Kaligorou Lloyd]]
[[http://renewablegossip.com/homemade-solar-parabolic-trough-hits-300-degrees-on-first-attempt/ 300degrees]]
[[http://www.stginternational.org STG international]]
[[http://pgirl.wordpress.com/2009/01/26/solar-heater-parabolic-trough/ Pgirl’s blog]]
[[http://www.ffwdm.com/solar/solar-index.htm George Workshops]]
[[http://www.thesietch.org/projects/distiller/index.htm Water Distiller]]
[[http://www.compatibletechnology.org/whatwedo/devices/Roaster-Building.pdf A wooden version]]
[[http://www.beartrapent.com/InfiniTherm.htm Infinitherm]]

=====Closed Top Design=====
[[http://www.sunreign.com/info/ParabolicTroughClosedGang Gang Xiao]]

=====How to Calculate a Parabola=====

====Parabola Theory====

We have a page devoted to the formula used to calculate parabolic collectors here. To simply calculate the curve you can use the suggestions below.

====Geobra====
You can use a tool like [[http://www.geogebra.org/cms/ Geobra]] to calculate arbitrary parabolic shapes. The Formula for a parabola is y=x*x. 
If you want to specify the focal length you can use the formual y=(x*x)/4*F where F is the focal length you want. 

""<img src='http://www.sunreign.com/images/parabool2.jpg'>""

====Wolfram====
Another way is this [[http://demonstrations.wolfram.com/ParabolicTroughSolarConcentrator/ Wolfram]] demonstration. It is not 100% correct, it calculates the concentration ratio from the apperture devided by the circumference of the tube. the tube however is mostly lit from the sides and bottom, so that doubles the concetration ratio.