Dhaka, Jan. 9 -- On cold winter evenings, when households retreat indoors and factory floors fall quiet, sprawling fleets of power plants hum not with activity, but with costly silence. Chimneys stand cold, turbines idle, and transmission lines carry far less electricity than they were built to bear.

This winter, the paradox of plenty has reached a new and troubling extreme: despite an installed power generation capacity nearing 29,000MW, as much as three-quarters of the country's power plants have often remained unused.

What was once justified as preparedness for growth has hardened into structural excess. Experts say the scale of overcapacity now visible during the winter months has exposed long-standing, politically driven flaws in B...