Abstract: A solar energy collector having a plurality of elongated upwardly-open trough-shaped reflectors placed side by side and each having facing reflective surfaces joined by a curved section disposed about a medial axis of each trough and supported by a series of templates spaced along the reflectors and having upwardly opening recesses the walls of which engage and shape the reflectors, the edges of the reflectors being held by locking members engaged on the templates between the said recesses, to accurately locate the side edges of the reflectors and hold the reflectors in stressed relationship in the templates, a frame supporting the templates and arranged to be oriented about a horizontal axis, heat collector tube being supported by the said frame and disposed at the focal area of each of the reflectors and constructed to act as an absorber of heat focussed on to it by the reflectors.