Washington Public Power Supply System defaults (1983)
A consortium of Washington state utilities launched five nuclear plants on forecasts of soaring electricity demand. Construction costs rose and demand growth slowed. The project collapsed with $2.25 billion of bonds in default, at the time the largest municipal-bond failure in U.S. history.
Two plants were finished; three were abandoned after about $2 billion had been spent.
The default shaped how regulators and lenders treat forecasts of future demand for decades.
AEP's plan rests on 84 gigawatts of contracted load by 2031, and only 35 gigawatts are on firm take-or-pay terms. The gap between forecast and signed contract is the same variable that broke WPPSS.
