[Update: it turns out this is an old article. (There was no date, except the current date at the top.) So, never mind. I'll let it stand because it has a little background info too.]
Power cuts threat as sun storm hits earth, article.
The solar flare was classified as an X18-category explosion, meaning it can trigger planet-wide radio blackouts and long-lasting radiation storms.
Although the charged particles present no direct danger to people on the ground, they could have a devastating effect on electrical equipment.
[...] The result could be widespread power surges and even blackouts...
It seems it may be a good idea to keep important computers turned off tonight if you can, and unplug them. (A big powersurge can easily leap a turned-off switch, I've heard.)
An engineer from a big computer support company told me once that they always have a lot more work on the day after a lightning storm, particularly in the industrial areas, where a lot of devices are running 24/7.
I have installed powerstrips with power surge protection at critical places. Even so those have a limit, so I unplug the machines if an electrical storm comes close (less than several seconds between a lightning flash and the boom).