The Pakistan Times reported as far back as May 2008:
Pakistan is suffering a serious crisis in the electricity generation sector. According to a recent estimate around 67% of the nation’s population lives in darkness.
The power shortage is a chronic problem that has slowed Pakistan’s social and economic growth. The problem is not a new one and dates back to the early nineties when the power supply was exceeded by the demand for electricity by thousands of MW.
The Wikipedia entry on Pakistan’s electricity sector says:
For many years the matter of balancing Pakistan's supply against the demand for electricity has remained a largely unresolved matter. Pakistan faces a significant challenge in revamping its network responsible for the supply of electricity.
While the government claims credit for overseeing a turnaround in the economy through a comprehensive recovery, it has just failed to oversee a similar improvement in the quality of the network for electricity supply.