farms.farms_dni

This model updates the computation of DNI used for FARMS. The orignal FARMS use DISC model to compute cloudy-sky DNI. This new model uses a physics-based algorithm to solve the direct and scattered beam in the circumsolar region.

Created on March 1, 2022 Upgraded on March 21, 2023 FARMS-DNI model developed by Yu Xie (yu.xie@nrel.gov)

References

Xie, Y., Sengupta, M., Dudhia, J., 2016. A Fast All-sky Radiation Model for Solar applications (FARMS): Algorithm and performance evaluation. Sol. Energy

135, 435-445.

Xie, Y., Sengupta, M., Liu, Y., Long, H., Min, Q., Liu, W., Habte, A., 2020. A physics-based DNI model assessing all-sky circumsolar radiation. iScience 22,

doi.org/10.1016/j.isci.2020.100893.

Yang, J., Xie, Y., Sengupta, M., Liu, Y., Long, H., 2022. Parameterization of cloud transmittance for expeditious assessment and forecasting of all-sky DNI. J. Renewable Sustainable Energy 14, 063703.

Functions

Pice(Z, tau, De)	Compute cloud transmittance for ice clouds The defination and use of the transmittance can be found in Xie et al. (2020) The cloud transmittance is parameterized by Yang et al. (2022).
Pwater(Z, tau, De)	Compute cloud transmittance for water clouds The defination and use of the transmittance can be found in Xie et al. (2020) The cloud transmittance is parameterized by Yang et al. (2022).
TDD2(Z, Ftotal, F1)	Compute surface reflection that falls in the circumsolar region.
TDDP(Z, tau, De, phase1, phase2)	Compute cloud transmittance of DNI for water and ice clouds More details can be found in Xie et al. (2020).
farms_dni(F0, tau, solar_zenith_angle, De, ...)	Fast All-sky Radiation Model for solar applications with direct normal irradiance (FARMS-DNI)