Local consumers paid big price for idle plant in 1993. (South Texas Project nuclear power plant) (Power Drain: Costly Questions Cloud Nuclear Plant)

While the South Texas Project nuclear power plant generated no electricity for 12 months, Houston Lighting & Power Co. ratepayers shelled out about $364 million in continuing costs for the plant.

And they can expect to pay even more if HL&P prevails at a state regulatory hearing later this year.

Both units at the plant were shut down from early February of 1993 until last week by order of the Nuclear Regulatory Commission. During that time, HL&P was forced to buy replacement power at a cost of about $100 million, according to estimates by the Office of Public Utility Counsel.

The cost for that replacement power has not yet been reflected in customers' electricity bills -- but HL&P plans to request its inclusion.

So, contrary to …