This report examines solar irradiance data from 2024 across the Eastern Mediterranean, offering a preliminary forecast for 2025. Analysis of ground-level solar irradiance trends reveals valuable insights into expected solar power generation capacity across the region. A close relationship between irradiance levels and solar output is apparent, highlighting the impact of weather patterns on solar energy availability. In 2024, the average daily solar irradiance at Israel's IMS Bet Dagan station located in the Coastal Plain reached 5,572 Wh/m² per day - 8.8% higher than the multi-year average from 1965 to 2014 and in line with the preliminary estimate of 5,507±84 Wh/m² per day. This anomaly exceeded the annual standard deviation of ±4.0%, indicating a notable increase in solar flux. Preliminary 2025 data suggests that the trend will continue, with an estimated daily irradiance of 5,590±151 Wh/m², projecting another year of record-high solar potential in the Eastern Mediterranean.
Bet Dagan is the longest-operating station of the Israel Meteorological Service (IMS), monitoring ground-level solar energy flux since 1965, making it uniquely suited for long-term solar energy analysis in the Eastern Mediterranean. This study examines solar irradiance data in the region, in order to estimate the normalized output of individual solar power facilities and to identify potential long-term trends in irradiance linked to climate change and other influencing factors. Variability in ground-level solar flux is primarily influenced by regional weather patterns and climate trends, driven by natural planetary shifts and, more recently, anthropogenic impacts. Only a minor portion of this variability is due to fluctuations in the sun’s solar output, which remains relatively stable.
Over the past decade solar flux in the EastMed region has shown an increase above the multi-year average, as demonstrated with the increase above the 1965-2014 multi-year average at the Bet Dagan IMS station. In 2015, the solar flux was 5,269 Wh/m² per day, which is 2.6% above the multi-year average. This trend continued in subsequent years, with solar flux readings of 5,520 Wh/m² per day in 2016 (7.6% higher), 5,453 Wh/m² per day in 2017 (6.3% higher), 5,339 Wh/m² per day in 2018 (4.0% higher), 5,543 Wh/m² per day in 2019 (8.1% higher), 5,354 Wh/m² per day in 2020 (4.4% higher), 5,556 Wh/m² per day in 2021 (8.6% higher), 5,433 Wh/m² per day in 2022 (5.8% higher) and 5,433 Wh/m² per day in 2023 (5.8% higher). The highest level recorded in Bet Dagan since the measurements began in 1965 was in 2024 at 5,572 Wh/m² per day (8.8% higher).
The average cumulative solar energy flux measured in 2024 at the IMS station in Bet Dagan, located in Israel’s Central Coastal Plain, was 5,572 Wh/m² per day. This represents a 8.8% increase above the 1965-2014 multi-year annual average. This anomaly exceeded the standard deviation range of ±4.0% observed during the reference period, emphasizing the significant rise. Notably, 2024 continued a trend of over a decade of above-average solar flux values, suggesting potential shifts in regional solar irradiance patterns. This sustained increase aligns with regional and global climate influences, possibly impacted by both long-term atmospheric changes and recent environmental factors, further highlighting the need to track these shifts for accurate solar energy forecasting and system optimization.
An estimate for 2025, based on data from the first nine months of the year, is 5,590±150 Wh/m² per day, continuing the trend of above-average irradiance. This estimate once again exceeds the 1965-2014 multi-year average and remains outside the standard annual deviation of ±4.0% from the reference period. Consequently, 2025 is projected to maintain record-high solar irradiance levels in the Eastern Mediterranean, further supporting the recent trend of elevated solar flux values. This pattern echoes similar irradiance levels observed in the late 1960s and early 1970s, a period known for notable above-average solar flux. These recurring high flux measurements are valuable for assessing potential long-term climate or atmospheric shifts and for optimizing solar energy output in the region.
Increased solar irradiance on ground level is driving increased generation figures for PV facilities in the region - a phenomenon which may continue for some time. Among possible factors to alter this projection is an unexpected change in solar activity, change in regional weather patterns or a powerful volcanic eruption in equatorial or sub-tropical regions at an intensity of VEI 5.0 or above. Notably, despite the exceptionally high intensity of the Hunga Tonga Hunga Haapai eruption in January 2022 at VEI 6, the eruption effect on global weather has not been substantial.
