LMP Investment Signals

A node in downtown Houston consistently shows LMPs of $80/MWh while a node 200 miles west in wind-rich West Texas shows $20/MWh. That $60 spread is a neon sign flashing "build generation near Houston" or "build transmission from West Texas." LMPs do not just settle markets; they signal where new investment would be most valuable.

Persistently high LMPs at a node indicate one of three things: local generation is expensive, transmission into the node is congested, or local demand exceeds what existing infrastructure can serve cheaply. Each diagnosis points to a different investment. Expensive local generation signals an opportunity for cheaper alternatives (solar, batteries). Congestion signals the value of new transmission. Excess local demand signals the value of demand response or distributed generation.

ERCOT's West Texas-to-Houston spread. West Texas has massive wind capacity but limited transmission to Houston. Wind generators receive depressed local LMPs (sometimes negative) while Houston pays premium prices. The CREZ (Competitive Renewable Energy Zones) transmission buildout was justified by exactly this price signal: the persistent LMP differential demonstrated that transmission investment would reduce total system costs.

Why don't LMP signals always attract efficient investment?

Because investors face risks that LMPs do not reflect. Today's congestion pattern may change when planned transmission is built. A generator sited at a high-LMP node may see prices drop once new supply enters. Regulatory changes can alter market rules. And transmission investment decisions are made by RTOs and regulators, not by market participants responding to LMPs. The signal is clear, but the investment pathway is not.

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