A1.zip

Description

Title: Monitoring data set at A1 (test-site of Totalp), years 2018-2022 Provider: ZHAW - EKZ Edition: Y.Frischholz, Laboratory of Cryospheric Sciences, EPFL Last edition: 17.01.2024 File name structure: The test site contains 6 segments named from A to F. The six files provided in the data/ subfolder follow the same naming convention (e.g. for segment A, the file name is: “A1_A.csv”). Refer to the publication for further details on the setups of the segments. File format: All files are provided in the CSV format. Column headings: • timestamp (datetime64): time stamp in format “YYYY-MM-DD HH:mm:ss”, time-zone: UTC • poa_front (double): front plane-of-array irradiation (W/m2) • poa_back (double): rear plane-of-array irradiation (W/m2) • mod_temp (double): module’s temperature (°C) • P_AC (double): output AC power (W) Preprocessing: Outliers: ⁃ Quantiles Q1 and Q99 are computed for each variable ⁃ Values below Q1 and above Q99 are considered outliers ⁃ Outliers are replaced by NaNs. Missing data: ⁃ Data holes of less than 3 hours are interpolated linearly for all variables ⁃ Data holes of more than 3 hours are replaced using the monthly nan-mean of the considered hour if more than 50% of the qualifying data points are available. For instance, if the data point 2022-12-12 12:12:00, is missing for a given variable and is part of a data hole larger than 3 hours, then it is replaced by the mean of all data points with hour = 12 of the month of December 2022, if 50% of all the qualifying data points are not NaN. In case more than 50% of the qualifying points are missing, the data point remains as missing (NaN). Wiring losses : ⁃ As described in [1] , the test-site setup caused abnormally large wiring losses, mainly due to the distance to optimisers and to the low installed power per DC-wire. ⁃ The wiring losses comprised between 10% and 15%, are averaged hourly and added to the measured DC power.

Misc.: ⁃ P_AC is computed for each segment based on the measured DC power and the average inverter’s efficiency (96.1%). ⁃ As described in [1], the peak power of the installed module, used to compute the final yield is slightly different from the values announced by the manufacturer. Mean uptime: Raw: ⁃ 95.2% Processed: ⁃ 100% References: [1] D. Anderegg, S. Strebel, and J. Rohrer, “Alpine Photovoltaik Versuchsanlage Davos Totalp : Erkenntnisse aus 5 Jahren Betrieb,” de, Sep. 2023, Accepted: 2023-09-29T09:13:16Z Publisher: ZHAW Zürcher Hochschule für Angewandte Wissenschaften.DOI: 10.21256/ zhaw-2524. [Online]. Available: https://digitalcollection.zhaw.ch/handle/11475/28797 (visited on 12/15/2023).