Comparative Analysis of All-Sky Luminous Efficacy Models Based on Calculated and Measured Solar Radiation Data of Four Worldwide Cities

Figure 4

Scatter plotting of diffuse solar radiation and luminous efficacy models performance for Manchester, UK (1993).

(a) Solar irradiance—Z&H model (MBE: 5.0%, RMSE: 41.4%)

(b) Illuminance—Perez model (MBE: −9.0%, RMSE: 39.2%)