Energy Storage is the Holy Grail of the electric power sector as it seeks to de-carbonize generation in response to climate change by integrating intermittent renewable power resources. According to market research firm IHS, the energy storage market is set to 'explode' to an annual installation rate of 6 GigaWatts (GW) in 2017 and over 40 GW by 2022.
In California, one-third of electric capacity must be obtained from renewable resources by 2020, with solar energy procurements increasing dramatically. This rapid growth of solar generating capacity is changing the load profile served by the California Independent System Operator (CAISO). The 'Duck Curve' is CAISO's actual and projected demand for power, and shows that solar generating capacity depresses the load on the grid during the middle of the day, followed by a severe load ramp in the evening.
The Duck Curve shows:
Overgeneration when excessive PV generation necessitates the curtailment of efficient combined cycle power plants.
Rapid Ramping as PV generation starts up and winds down, which would require fast-start generating units that are also capable of flexible load following.