The ERCOT system set a new record for June peak demand last week, reaching 69 GW on June 27 during the hour ending 5 p.m.

That shattered the previous record of 67.9 GW, which was set on June 1. The new record withstood strong challenges the following two days, with demand reaching 68.6 GW on June 28 and 68.4 GW on June 29.

Demand broke the pre-2018 record of 67.6 GW during eight hourly intervals over the three-day span. Real-time average prices only broke triple digits once during that time, hitting $128.98/MWh in the interval ending at 1:30 p.m. on June 29.

Temperatures climbed into the 100s F in much of Texas last week, with heat indexes approaching 110.

ERCOT has projected a summer peak of 72.8 GW in August, which would break the 2016 record of 71.1 GW. It says it has 78.2 GW of capacity available, with a planning reserve margin of 11%. (See ERCOT Gains Additional Capacity to Meet Summer Demand.)

— Tom Kleckner