Abstract: An solar energy harvester and method for controlling the solar energy harvester, in which an insolation collector is formed of one or more elements each having two opposite major sides, a first side and a second side, and being configured to collect energy from insolation incident on any of the first and second sides. A cradle enables installation of the insolation collector on a roof with the first side generally towards the sun independently of the form of the roof. One or more heliostats reflect insolation to the second side of the insolation collector. A controller controls the one or more heliostats to maintain reflected insolation incident on the collector and to decrease the reflected insolation incident on the collector when necessary to inhibit the insolation collector receiving insolation exceeding given threshold through its first and second sides.