HYGEOS at EMS 2024 conference

SolaRes® is the HYGEOS operational service providing near real time and historical archives of solar resource estimate. SolaRes® output are constantly compared with high-quality ground-based measurements to check its performances, in terms of accuracy and precision, for estimating the solar resource. In the work presented at the 25th conference of the European Meteorological Society (EMS), we showed the advantage in using Solares® to compute not only the Global Horizontal Irradiance (GHI) standard parameter but also what is effectively collected by a tilted Silicon sensor. Presentation is available here.

SolaRes® estimates were compared to measurements by the PV-Live network. Every station of this network is equipped by 4 instruments: one thermopile pyranometer measuring the GHI, and three Silicon sensors measuring radiation in the spectral and angular conditions of the photovoltaic panels. All Silicon sensors are tilted by 25° and orientated in the three orientations south, east, and west. We demonstrate that SolaRes® generates no loss in precision in computing GHI or radiation collected by a Silicon sensor, in clear-sky conditions. The Root Mean Square Difference (RMSD) in both GHI and GTI (T for tilt, western-direction instrument) at the station of Freiburg (Germany) was 3% in clear-sky conditions at 1-hour resolution. SolaRes® then shows better performances than a parameterisation model which increases the uncertainty in GTI, converted from GHI through the decomposition and transposition techniques. RMSD in GHI and GTI was smaller than 20% in all-sky conditions, and smaller than 18% in 45% of the time, defined by a cloud optical thickness smaller than 2.

Constant research is pursued at HYGEOS to improve precision on SolaRes® products. A next step is to exploit most sophisticated information delivered by geostationary satellite on the cloud microphysics, like the cloud droplet effective radius and phase (liquid or ice) provided by the Satellite Application Facility on support to NoWCasting and very short-range forecasting (NWC SAF).

Thanks to a close collaboration with the Laboratoire d’Optique Atmosphérique and other European research teams, HYGEOS expert contributed to three oral presentations made at EMS conference 2024:

  • Elias, T., Ferlay, N., Moulana, M., Saint-Drenan, Y.-M., Metzger, S., Feigel, G., Chesnoiu, G., and Chiapello, I.: Comparison between SolaRes estimates of the tilted solar irradiance and measurements by the PVlive network, EMS Annual Meeting 2024, Barcelona, Spain, 1–6 Sep 2024, EMS2024-924, https://doi.org/10.5194/ems2024-924, 2024.
  • Ferlay, N., Chesnoiu, G., Chiapello, I., and Elias, T.: Aspects of time variability of the surface solar irradiance as measured and analysed from ground-based measurements with a distinction of cloudyness , EMS Annual Meeting 2024, Barcelona, Spain, 1–6 Sep 2024, EMS2024-962, https://doi.org/10.5194/ems2024-962, 2024.
  • Saint-Drenan, Y.-M., Lezaca, J., Schroedter-Homscheidt, M., Blanc, P., and Elias, T.: Spatial evaluation of CAMS Radiation service using dense pyranometric networks , EMS Annual Meeting 2024, Barcelona, Spain, 1–6 Sep 2024, EMS2024-840, https://doi.org/10.5194/ems2024-840, 2024.