Red lights have begun flashing at Eskom after electricity use has crept up to the point at which “involuntary curtailment” (aka blackouts) kicked in last year. "We've seen a steady increase in electricity demand over the past three months as large mines and smelters have returned to full production ... we have basically seen a full return of the demand to levels seen prior to the global economic crisis," spokesman Andrew Etzinger told Reuters at the weekend. The recession has saved Eskom’s blushes up until now, but Etzinger said the system was under pressure and “vulnerable to incidents”, which presumably means the “involuntary curtailment” exercises. The problem reflects the extent to which SA is vulnerable to things called “ceiling blockers” which allow economic growth, but only to a certain level or height, after which they hit the ceiling, and growth must stop. Eskom is the prime example of this phenomena, but by no means the only one. Of course, those with eyes on power capacity for next year’s Fifa Soccer World Cup may be forgiven for feeling a little edgy. Numerous sporting events fell victim to “involuntary curtailments” last year.