α Absorptivity (%)
γ Intercept factor
ηSF Solar efficiency
ηcc Combustion efficiency
ηe Electrical efficiency
\(\eta_{\text{\ ISCC}}\) Efficiency of the plant
ηm Mechanical efficiency
ηoptique Optical efficiency
ηp Pump efficiency
θ Angle of incidence [deg]
θz Zenith angle [deg]
\(\rho\) Reflectivity
τ Transmissivity
τb Atmospheric transmittance
\(\varphi\) Latitude [deg]