SPP set a new record for system demand Monday as a heat wave swamped the southern Midwest and Great Plains.
The system’s demand peaked at 50.66 GW at 4:39 p.m. as temperatures hit 101 degrees Fahrenheit in Oklahoma City. That broke SPP’s historical peak load of 50.62 GW, set in July 2016.
Average prices in the RTO’s footprint dropped from $36.08/MWh at 4:30 to $28.81/MWh at 4:45. The south and north trading hubs did not get above $31.14/MWh during that time.
The low prices likely resulted from strong wind production, which exceeded SPP’s forecast. SPP’s Market Monitoring Unit said in its most recent annual market report that unexpected high wind generation can lead to lower real-time prices. The market’s wholesale prices averaged around $28/MWh in 2018.
Monday’s average day-ahead price was $66.99/MWh, when the National Weather Service placed eastern Oklahoma under an excessive heat warning. The NWS projected heat indexes approaching 115 F in the state and parts of neighboring Arkansas.
— Tom Kleckner
