Interference filter with angular independent orange colour of reflection and high solar transmittance, suitable for roof-integration of solar energy systems

olar glazing unit, suitable for photovoltaic modules and solar thermal collectors, comprising a substrate delimited by two main faces and a multi-layered interference filter also delimited by two main faces, one main face of said substrate being adapted to be in contact with an incident medium, the other main face being in contact with a main face of said interference filter, the other main face of said interference filter being adapted to be in contact with an exit medium; said incident medium having a refractive index ninc = 1, said substrate having a refractive index nsubstrate defined as follows : 1.45 ≤ nsubstrate ≤ 1.6 at 550 nm, and said exit medium having a refractive index nexit = 1 or defined as follows 1.45 ≤ nexit ≤ 1.6 at 550 nm; and wherein said unit is designed in such a way that the CIE colour stability ΔENorm, as observed under daylight illumination CIE D65 at higher angles of reflection Θr (Θr > 10°), is less than 15 or ΔENorm ≤ (Θr / 3°) for 10° < Θ ≤ 60°.