A 40-Year Bet: Outdated Before It's Paid Off?

To be clear, this isn't a claim that the wires stop working — high-voltage lines are mature and last for decades. The risk is economic: a $2-billion-plus, single-purpose greenfield line gets locked in for ~40 years on today's assumptions, just as the alternatives keep getting cheaper and better — utility-scale and home batteries, long-duration storage, advanced-conductor upgrades to existing lines, virtual power plants, and, for genuinely long hauls, more modern options than 500 kV AC. The utility earns its guaranteed return either way; ratepayers carry the risk that the bet doesn't age well. ^[1]

This isn't hypothetical: in its 2025–2026 plan, California's grid operator canceled a brand-new 500 kV line because cheaper alternatives had caught up. A line approved one cycle can be the wrong bet the next. ^[2]

The CPUC has warned about exactly this. In denying SDG&E's Valley-Rainbow line, it cautioned that planning too far out on uncertain forecasts risks “substantial investment in resources that are never actually needed.” And under “used and useful” / prudence review, costs for infrastructure that turns out not to be needed can, in principle, be challenged. The forty-year horizon is a reason for more scrutiny of the need, not less. ^{[3] [4]}

Demand could also rise — electrification, EVs, and data centers — and the grid will need more storage and transmission overall. So the argument is narrow and specific: this long greenfield line, justified on current assumptions, is a risky multi-decade lock-in when modular, faster-improving options exist. It's about the bet, not a claim that transmission is dead. (Stub — a fuller treatment, with real cost-trajectory sources, is coming.)