SkyTrough uses a polymer-and-silver layered mirror-film called ReflecTech instead of ­conventional glass mirrors for its reflective surface.

Tests at the the NREL showed it to have a thermal effici­ency of more than 73% at 350°C, meaning nearly three quarters of the solar radiation striking the trough is turned into thermal energy.

This high thermal efficiency — which compares closely to that of conventional glass mirrors — comes from the combination of the optical efficiency of the trough’s mirror-film (how well it focuses sunlight) and the ­receiver heat loss.

The