Daily measurement import

PVsyst custom import can import daily weather measurements. This is a legacy option that is not recommended anymore, given the wide availability of hourly irradiance data available today.

Hourly values for irradiance and temperatures will be generated from your daily input. Two methods are available:

• Clear sky shape: irradiance is given by the clear sky profile, normalized to the daily input irradiance
• Markov distribution: a random distribution is generated according to the Markov matrices, in the same way as when generating synthetic data.

The second method is more realistic, but global simulation results are not very different. In both cases, temperature is generated using the usual synthetic temperature generation

Import process

1. Follow the usual custom import procedure.
2. Define your data source as daily in the Date tab.
3. Chose the method to build hourly data