Solar panel mirror unit being curve shaped and having a sandwich structure, said sandwich structure comprising the following material layers: an outermost front reflecting layer, intended as the sun reflecting layer and therefore having a reflective coating, said outermost front reflecting layer consisting of a first material having a first thermal expansion coefficient; an intermediate layer having a honeycomb structure and being the core of the sandwich structure, wherein the thickness of the honeycomb structure does not exceed 50 mm; and an innermost rear layer consisting of a second material having a second thermal expansion coefficient; wherein the solar panel mirror exhibits a symmetrical cross section in relation to layer materials on both sides of the intermediate layer, wherein said first and second thermal expansion coefficients are equal or substantially equal, wherein the outermost front reflecting layer and the innermost rear layer are comprised of different materials than the intermediate layer wherein the average solar reflectivity is at least 90%, wherein the front reflective layer on a rear side thereof is adhered directly to the intermediate layer, and wherein the intermediate layer is adhered to the rear layer, so as to form the shaped solar panel mirror unit having only three layers in total, wherein the intermediate layer is made of aluminium or an aluminium alloy or of a composite material, characterized in that the outermost front reflecting layer consists of a glass material and the innermost rear layer consists of a glass material, and the reflective coating is applied on the rear side of the outermost front reflecting layer. an outermost front reflecting layer, intended as the sun reflecting layer and therefore having a reflective coating, said outermost front reflecting layer consisting of a first material having a first thermal expansion coefficient; an intermediate layer having a honeycomb structure and being the core of the sandwich structure, wherein the thickness of the honeycomb structure does not exceed 50 mm; and an innermost rear layer consisting of a second material having a second thermal expansion coefficient; wherein the solar panel mirror exhibits a symmetrical cross section in relation to layer materials on both sides of the intermediate layer, wherein said first and second thermal expansion coefficients are equal or substantially equal, wherein the outermost front reflecting layer and the innermost rear layer are comprised of different materials than the intermediate layer wherein the average solar reflectivity is at least 90%, wherein the front reflective layer on a rear side thereof is adhered directly to the intermediate layer, and wherein the intermediate layer is adhered to the rear layer, so as to form the shaped solar panel mirror unit having only three layers in total, wherein the intermediate layer is made of aluminium or an aluminium alloy or of a composite material, characterized in that the outermost front reflecting layer consists of a glass material and the innermost rear layer consists of a glass material, and the reflective coating is applied on the rear side of the outermost front reflecting layer.