sentences:  G-value (sometimes also called a Solar Factor or Total Solar Energy Transmittance) is the coefficient commonly used in Europe to measure the solar energy transmittance of windows.Despite having minor differences in modeling standards compared to the SHGC, the two values are effectively the same.A g-value of 1.0 represents full transmittance of all solar radiation while 0.0 represents a window with no solar energy transmittance.