Synthetic high-temporal resolution irradiance time series generator

Any use of the ND model in reports, articles, publications, presentations, or any other media format, should cite the following article for reference purposes: Larrañeta M., Fernandez-Peruchena C., Silva-Pérez M.A., Lillo-Bravo I. 2018. Methodology to synthetically downscale DNI time series from 1-h to 1-min temporal resolution with geographic flexibility. Solar Energy 162, 573-584

The ND model

For the synthetic generation of 1-min data from hourly means, we implement the following steps in a daily basis:

  1. Normalize the 1-min daily curves. We calculate the clear sky DNI envelopes and the extra-terrestrial solar radiation to generate a database of dimensionless daily coupled GHI and DNI profiles for the location of Adelaide. Each day of the dimensionless database has been labelled with the calculated k_b, k_t, VI and F_m for that day
  2. Seek for the most similar day in terms of energy, variability and distribution. We use the daily synthetic quartets of k_b, k_t, VI and F_m synthetically generated in step 2 to find the most similar day in terms of Euclidean distance in the dimensionless database to the given day.
  3. Generation of synthetic coupled 1-min DNI and GHI series on a given day. We combine dimensionless daily DNI and GHI curves with the theoretical estimated envelope and extra-terrestrial profiles for the given day.

Input file

Select csv comma-delimited file on disk. Use point as decimal separator. Input file may contain four columns of valid values of 8760 rows corresponding to aggregated hourly data.

  • Column 1. Day of the year. From 1 to 365. Leap years not supported.
  • Column 2. Hour of the day from 1 to 24. Input data first row corresponds to hour 1.
  • Column 3. GHI.
  • Column 4. DNI.


In degrees. North positive


In degrees. East positive

Climate clasification

Select the Koppen climate classification of the drop list referred to the input data

World map of Köppen-Geiger climate classification

Time Zone

Hours offset from GMT

Validation check

The software runs a validation check of the input data. The clearest daily profile of each month is plotted. Please check the correct alienation of the input data to the estimated clear sky data. Change input data file if necessary and run the validation again. After the validation is fulfilled a “synthetic generation” bottom will be available. We will send you a Zip file with the synthetic 1-min data via Email.