Apply for two layers 3.3 high borosilicate glass tube. The two layers glass tube, with same axis is vacuumize between them, the vacuum degree can reach 5*-2Pa. Coated with SS-CU-ALN/ALN selective absorbing coating material. High absorbing efficiency: the vacuum magnetic-control sputtering selective basorptive coatings on the heat-collecting plates has a high absorption coefficient of more than 93%.and the emission coefficient around 6%. Long life: the life span can reach 15 years. High practicability: able to endure impact of hail less than 25mm in diameter with high heat efficiency throughout the year.