California's utility-scale solar photovoltaic (PV) and concentrated solar power (CSP) output reached a record-breaking peak of 3.048 GW shortly after noon on January 2, 2014, despite it being one of the shortest days of the year.
The California Independent System Operator (ISO) reported that total PV output peaked at 12:11 pm at 2.792 GW, with CSP peaking at 264 MW later in the day at 2:51 pm. The combined peak of the two occured at 12:02 pm.
This record of 3.048 GW is quite a bit above the 2.61 GW record set in September 2013, a month with longer days. That may be a result of a number of large PV plants being commissioned in California in the second half of 2013.
These figures don't even include the state's distributed PV systems, because the ISO doesn't record their output. That could account for as much as an additional 2 GW. However, even without including distributed PV, utility-scale PV and CSP met around 12% of demand -- 26 GW -- during peak output.