Resumo:
In this work, the cloud enhancement effect produced by clouds as an intensification
event of solar irradiance reaching the surface was studied using pyranometer data and
satellite imagery in a coastal region of Maranhão during 382 days of measurements
between November 2021 and December 2022. The Quality Control method applied to the
pyranometer data allows the filtering of unreliable data linked to measurement uncertainties
for a correct detection of the effect. The phenomenon was found to produce additional
irradiance above the solar constant on 31 different days. The highest irradiance detected
was 1565.9 W/m2, and in some cases events exceeding 1200 W/m2 lasted from a few
seconds up to 7.6 minutes, which could represent a risk for undersized photovoltaic systems.
The use of geostationary satellite imagery and the atmospheric lapse rate concept were
used for cloud top height estimation and revealed that these events were caused by lowand
mid-level clouds, ranging from 2 to 8 km cloud top height. The results suggest that
clouds can have a significant impact on solar energy production by significantly increasing
irradiance levels and should be taken into consideration in future studies and modeling
of solar energy potential and their importance considered in the design and operation of
photovoltaic systems in Maranhão.
