March brought exceptional solar energy conditions to southeastern Brazil and parts of northern South America, where irradiance levels were significantly higher than average. Despite ongoing convective rain systems and heavy rainfall in the Amazon, irradiance remained robust across much of Brazil. The Solcast API data attributed these favorable conditions to high solar irradiance across solar-rich southeastern states, helping solar producers take advantage of extended sunny intervals between rain events.
High Pressure and Stable Air Boost Solar Irradiance Despite Heavy Rainfall Events
Southern Brazil and the northern Andes emerged as irradiance hotspots, registering anomalies as much as 30% above climatological norms. This outcome was notable given the intense rainfall and flooding seen in countries like Bolivia, Argentina, and Brazil.
Typically, high rainfall reduces irradiance, but in this case, a persistent high-pressure system over eastern Brazil disrupted cloud formation. This unique pattern created alternating periods of sunshine and sporadic, heavy rainfall, allowing for increased solar exposure even as precipitation levels surged.
Unusual Weather Patterns Boost Solar Irradiance in Brazil While Andes Face Sharp Decline
The Caribbean nations also experienced above-average solar irradiance, supported by stable atmospheric conditions that inhibited cloud formation. Mild weather and some precipitation occurred, but the lack of long-lasting cloud cover allowed for consistently strong solar generation. These conditions mirrored the favorable patterns seen in Brazil, as similar air mass stability extended northward from South America into the Caribbean basin.
Persistent Cloud Cover Diminishes Solar Output Across Andes and Western Lowland Regions
In contrast, the Andes and nearby lowland regions faced poor solar conditions. Elevated sea surface temperatures in the South Atlantic contributed to moist air flowing westward, where it met atmospheric instability caused by a mid- to upper-level trough over the Andes. This combination encouraged deep, persistent cloud development, severely limiting sunlight and reducing the efficiency of solar energy systems in these areas.
The prolonged cloud cover had a significant negative impact on solar irradiance from northern Argentina through Paraguay, Bolivia, and into central Peru. In these zones, irradiance fell as much as 30% below normal, representing a sharp deviation from expected seasonal performance. For regions typically known for their solar productivity, this March marked a setback, highlighting the importance of dynamic climate patterns in influencing solar generation potential.
