Sure, but it is still a small portion. The link I provided to the 8% stat is for overall California power use, including imports. Now, there is also the 12% “unspecified sources of power” at the bottom of the chart that might include some coal. I'm not sure what “unspecified” means exactly, but my best interpretation of the text at the bottom is “the portion of imports for which we were not sure what the source was.” There is no breakdown there, but we can make a few inferences.
A third of electricity imports come from the Pacific Northwest grid which gets 30% of their electricity from coal. Two-thirds come from the U.S. Southwest grid and they get 39% of their electricity from coal. (source, see page 5/6) So maybe add another 5% to the 8% coal figure, giving us 13%?
Any way you cut it, they use much less coal than the coal-heavy areas discussed in the article we are commenting on.