PG&E says it's putting opaque walls in place of chain-link fences at substations.
Last April, someone shot at transformers at a San Jose substation with a high-powered rifle.
Former Federal Energy Regulatory Commission Chairman Jon Wellinghoff says he believes it was terrorism.
The FBI disagrees, but PG&E says it's beefing up its defenses anyway, and will aslo add advanced camera systems, enhanced lighting and additional alarms.
Spokesman Brian Swanson says the cost may show up in your PG&E bill.