1. U.S. Energy Information Administration. Electric Power Monthly; 2016. .
2. California Independent System Operator. What the Duck Curve Tells us about Managing a Green Grid; 2016. .
3. Steen D, Goop J, G’oransson L, Nursbo S, Brolin M. Challenges of integrating solar and wind into the electricity grid. Systems Perspectives on Renewable Power; 2014.
4. International Electrotechnical Commission. Grid integration of large capacity renewable energy sources and use of large-capacity electrical energy storage; 2012. .
5. St. John J. The California Duck Curve is Real, and Bigger than Expected; 2016. .