High-Resolution Solar Climate Atlas for Greece under Climate Change Using the Weather Research and Forecasting (WRF) Model

Abstract

In the context of climate change and growing energy demand, solar technologies are considered promising solutions to mitigate Greenhouse Gas (GHG) emissions and support sustainable adaptation. In Greece, solar power is the second major renewable energy, constituting an increasingly important component of the future low-carbon energy portfolio. In this work, we propose the use of a high-resolution regional climate model (Weather Research and Forecasting model, WRF) to generate a solar climate atlas for the near-term climatological future under the Representative Concentration Pathway (RCPs) 4.5 and 8.5 scenarios. The model is set up with a 5 × 5 km2 spatial resolution, forced by the ERA-INTERIM for the historic (1980–2004) period and by the EC-EARTH General Circulation Models (GCM) for the future (2020–2044). Results reaffirm the high quality of solar energy potential in Greece and highlight the ability of the WRF model to produce a highly reliable future climate solar atlas. Projected changes between the annual historic and future RCPs scenarios indicate changes of the annual Global Horizontal Irradiance (GHI) in the range of ±5.0%. Seasonal analysis of the GHI values indicates percentage changes in the range of ±12% for both scenarios, with winter exhibiting the highest seasonal increases in the order of 10%, and autumn the largest decreases. Clear-sky fraction fclear projects increases in the range of ±4.0% in eastern and north continental Greece in the future, while most of the Greek marine areas might expect above 220 clear-sky days per year.

Effects of Aerosols and Clouds on the Levels of Surface Solar Radiation and Solar Energy in Cyprus

“…For example, in different locations in Cyprus, monthly averages of daily percentage of sun-shine of ~60% in winter and ~90% in summer have been reported [14,15]. The studies of Kalogirou et al, [16] and Pashiaridis et al, [17] report cumulative annual global horizontal irradiance (GHI) of 6700 -7300 MJ/m 2 for different sites in Cyprus, which is generally above the average annual GHI in the territory of southern European countries such as Greece and Italy [18,19] and comparable with average annual GHI reported for different sites in Malta and Andalusia, Spain [20,21].…”

High resolution projections for extreme temperatures and precipitation over Greece

“…The model evaluation showed by comparison to the available observational products that the downscaling reanalysis datasets to the domain of Greece produced reliable results at various temporal scales for minimum and maximum temperatures (TX and TN) and precipitation (PR), highlighting the added value of the downscaling methodology. This model was also validated for mean seasonal daily Global Horizontal Irradiation (GHI), clear-sky fraction/days (Katopodis et al 2020) and wind speed at 10m (Katopodis et al 2021). It is worth also mentioning that other relevant studies have indicated improved description of simulation results using the WRF model, clearly supporting its use as a regional climate model (Soares et al 2012b The selected GCM for our study was the EC-Earth model of the ECMWF Integrated Forecast System (IFS) that has been incorporated in CMIP5 and more recently in CMIP6 (Vautard et al 2021).…”

Solar Radiation Intensity Probabilistic Forecasting Based on K-Means Time Series Clustering and Gaussian Process Regression

“…Numerical Weather Prediction (NWP) [7]. Typical NWP models include European Centre for Medium-Range Weather Forecasts (ECMWF) [8], Fifth-generation Mesoscale Model (MM5) [9] and Weather Research and Forecasting (WRF) [10]. Mathiesen and Kleissl [11] evaluated the numerical forecast of daytime solar radiation intensity in the United States.…”