The real-time LMP spread across CAISO hit $1,288.91/MWh at 10:15 AM PT on July 11, the widest intraday gap in the session. Node SPRPPGNODE2 cleared at $89.23/MWh while BSPHYD341N001 posted negative $1,199.68/MWh, a $1,289 delta driven entirely by congestion.

The energy component was uniform at $27.56/MWh across all top nodes. The spread is pure congestion: SPRPPGNODE2 carried $50.76/MWh positive congestion, while BSPHYD341N001 and four CONTROLX nodes each showed negative congestion of $1,238.15/MWh. That is a forced flow reversal — the ISO is paying generators nearly $1,200/MWh to push power into a constrained pocket, or paying loads that much to take it off the system. The identity of the binding constraint is not yet confirmed, but the CONTROLX substation cluster and BSPHYD34 hydro unit are the obvious candidates. CAISO logged 1,668 curtailment events over the prior seven days, though the sample data shows near-zero MWh volumes, suggesting the count may reflect many small or zero-MW events rather than a systemic oversupply condition.

If this spread persists into the next binding constraint update, traders should watch for a derate or outage notice on the BSPHYD34 unit or the CONTROLX bus. A sustained negative $1,200/MWh LMP at a hydro node implies the unit is being dispatched down or off, with the ISO paying to keep it from injecting. Watch the 15-minute real-time price re-runs: if the spread collapses to $200-300/MWh in the next interval, this was a transient SCADA glitch or a single-interval constraint relaxation. If it holds or widens, the afternoon peak will see cascading congestion into adjacent nodes, and the day-ahead versus real-time basis for that path will blow out.

> A $1,289/MWh spread with uniform energy costs is a transmission constraint, not a supply event; the next constraint update will tell you if this is a five-minute spike or a five-hour problem.

Not investment advice. For informational purposes only.