There are several advantages to using flat plate technology of which the primary one is that of greatly reduced cost. The major drawback is that the engine works with a much lower temperature differential, hence lower efficiency and power output, however this is not a problem when applying solar technology in countries having limited financial resources.
One of the pioneers of low temperature solar machines is Bomin Solar Research of Germany who have been developing engines, designed to operate below 100°C, since 1989. One of their latest concepts is the SUNPULSE engine which consists of three mechanical components: the solar collector box, the oscillator control system and the mechanical power system.|
Unconcentrated solar radiation enters the solar box (3) through a transparent cover (2) and is absorbed by the black top (4) of the regenerator absorber (5) and converted into heat. The regenerator consists of material pervious to air and is moved up and down within the solar box.