The current problem, according to ISO spokeswoman Lorie O'Donley, is unplanned outages. There are also gas curtailments in San Diego affecting 800 megawatts. This combination of factors is what led to a stage three alert today. Power-producing problems are possible and could worsen Tuesday's power shortage. A stage 3 alert means power reserves have fallen below 1.5 percent and rolling blackouts are a possibility.
Blackouts are an emergency measure to prevent a collapse of the power grid.
Rolling blackouts involve switching off entire neighborhoods for about an hour at a time to relieve the strain on the system. This is the second Stage Three alert to be called in one week. Last week, a Stage 3 alert was called when the biggest storm to hit the state in three years cut electricity generation at a key nuclear plant. The alert was dropped back to Stage 2 on Friday, when more power became available from other states. State looks to buy power Trying to solve the problem, state and federal officials have been meeting in recent days with utility executives and electricity wholesalers.