# PJM modeling error wastes $12B of US ratepayer money

A modeling mistake in PJM, the largest US electricity grid operator, led to $12 billion in wasted ratepayer funds. The error distorted capacity market payments, causing customers to overpay for electricity. This highlights the financial stakes of technical flaws in power grid planning.

**Importance:** 4/5

## Sources

### Technology
- [Hacker News](https://newsletter.semianalysis.com/p/12b-of-us-ratepayers-money-wasted) — Mon, 17 Aug 2026 05:22:49 +0000