About
The algorithm for synthesizing one-minute time series
The algorithm provided on this website is described here: https://www.hindawi.com/journals/ijp/2014/808509/
Current version is 1.2
What it does
The algorithm synthesizes one-minute time series of global irradiance from one-hour input values.
Abstract of our publication:
High resolution global irradiance time series are needed for accurate simulations of photovoltaic (PV) systems, since the typical volatile PV power output induced by fast irradiance changes cannot be simulated properly with commonly available hourly averages of global irradiance. We present a two-step algorithm that is capable of synthesizing one-minute global irradiance time series based on hourly averaged datasets. The algorithm is initialized by deriving characteristic transition probability matrices (TPM) for different weather conditions (cloudless, broken clouds and overcast) from a large number of high resolution measurements. Once initialized, the algorithm is location-independent and capable of synthesizing one-minute values based on hourly averaged global irradiance of any desired location. The one-minute time series are derived by discrete-time Markov chains based on a TPM that matches the weather condition of the input dataset. One-minute time series generated with the presented algorithm are compared with measured high resolution data and show a better agreement compared to two existing synthesizing algorithms in terms of temporal variability and characteristic frequency distributions of global irradiance and clearness index values. A comparison based on measurements performed in Lindenberg, Germany, and Carpentras, France, shows a reduction of the frequency distribution root mean square errors of more than 60% compared to the two existing synthesizing algorithms.
Related publications
- Initial publication - Improved Synthesis of Global Irradiance with One-Minute Resolution for PV System Simulations (view at publisher, open access)
- A New Model for Estimating the Diffuse Fraction of Solar Irradiance for Photovoltaic System Simulations (view at publisher, open access)
- Influence of Various Irradiance Models and Their Combination on Simulation Results of Photovoltaic Systems (view at publisher, open access)
- Independent validation by Jan Remund, Meteotest (German and English)
Usage
PV*SOL
It is currently part of the commercial PV system design and simulation software PV*SOL, from Valentin Software, Berlin, Germany (where I work).
Meteonorm
It is also included in the newest version of the climatology data sources and model provider software MeteoNorm by Meteotest, Bern, Switzerland.
Research
Since it is quite complex to implement, I decided to publish the algorithm here for everyone free to use. It is aimed to fellow researchers for non-commercial use.
When you request a data download, your email address will be stored internally in an secured database. The number of syntheses will be counted. Please use moderately, since the server is not the strongest.
If you want to use the algorithm for your commercial projects, consider buying one of the software solutions above.
If you want to include the algorithm in your product, please contact me.