Sandia National Lab researchers are testing a new system that may ultimately provide a way for utility companies to predict and prepare for fluctuations in solar power output caused by changes in weather. The idea is that by observing cloud shape, size and movement, the system can monitor and predict how clouds will affect large-scale photovoltaic power plants and thereby allow utility systems to respond appropriately. The impacts of clouds on small PV arrays are well documented, but there is little research on how large-scale arrays interact and function under cloud cover. A small system can be completely covered by a cloud, which drastically reduces its power output, but what's less well understood is what happens when only part of a large system is covered by a moving cloud shadow, while the rest stays in sunlight.
