|Title||Understanding Variability and Uncertainty of Photovoltaics for Integration with the Electric Power System|
|Year of Publication||2009|
|Authors||Hoff, Tom, Carl Lenox, Nicholas Miller, Yih-huei Wan, Ray George, Joshua Stein, Benjamin Kroposki, Andrew D. Mills, Mark Ahlstrom, Michael Brower, and Abraham Ellis|
|Keywords||electricity markets and policy group, energy analysis and environmental impacts department|
Data and analysis are needed to understand the variability of photovoltaic (PV) plants to avoid unnecessary barriers to the interconnection of PV. Several data sets show clouds can cause rapid changes in solar insolation. Smoothing of rapid ramps, however, occurs within PV plants. The degree of smoothing depends on plant size. Smoothing occurs on even longer time-scales between separate plants.