Reflector could be used with solar home boiler units.

http://kr.blog.yahoo.com/eychung1888/ ---- Solar related blog

http://home.germany.net/100441770/amsi2.pdf ---- Parabolic design guide                                                             

http://home.germany.net/100-441770/amsi-model.html ---- Parabolic design guide                                                                             

http://mathworld.wolfram.com/Parabola.html ---- Parabolic design guide