Pick an hour
Cleared price and generation mix through the selected day. Click an hour to load its bid stack in the charts below.
Offer curves
MW offered at or below each price, averaged over the SCED runs in the hour. The line across the chart marks the cleared price for the hour; the shaded band is its range in that hour. With the 60-day report, "From LSL" draws each technology as the minimum output (LSL) of its online units plus the MW offered above that, so the curve runs flat at LSL and rises with the bids: minimum output runs however low the price goes, and only the MW above it can move by price. "As ERCOT prices it" shows the curves the way SCED sees them, with minimum output at −$20 (−$50 for some units) and the −$250 starts of some submitted curves. The Stacked view shades the LSL block from zero; hover for the split. More on what “From LSL” means.
Table view
Generation mix
Output by technology in the hour and each technology's share of total generation. With the 60-day report this is measured output; with the 2-day report it is an estimate from the offer curves at the cleared price.
Table view
Marginal supply
Who is offering at the cleared price: MW each technology offers between the hour's lowest and highest cleared price (at least ±$1 around the average), from the hourly offer curves (it follows the Curve and Price selections), with each unit's minimum output (LSL) taken out, since SCED cannot move a unit below it. Supply shares add to 100% of supply. Batteries that stop charging as price rises are demand, so they are drawn on the other side of zero as a share of the supply in the window (it can pass 100% when little supply moves; the chart stops at 100%). It shows who stands at the margin, not which unit set each SCED price; with congestion, units can set price locally at prices away from system lambda.
Table view
Marginal offer stack by price
Who would move next if price landed at each level: each technology's share of the MW offered around that price, read off the day's offer curves (the slope of the bid stack). Battery charging bids are demand, so they sit below the line as a share of the supply offered at that price. MW at the −$250 floor (units with no offer curve, mostly nuclear and hydro) are left out, and so is each unit's minimum output (LSL), which SCED cannot move: on days processed before that was done it still shows as a spike at −$20 (−$50 for some units). Ticks along the top mark each hour's system lambda. The same view across all days, by settled price, is on the Trends page.
Through the day
MW offered at or below the threshold in each hour of the selected day, with the cleared price below. It follows the Offer curves chart's minimum output setting: "From LSL" counts each technology's online minimum output (LSL) at every threshold, since it runs however low the price goes, plus the MW offered above it at or below the threshold; "As ERCOT prices it" counts minimum output only from −$20 (−$50 for some units) up, where ERCOT prices it. The same measure for every day and hour is under Across days on the Trends page.
Inflexibility by technology 60-day data
Units online, in the selected hour or averaged over the day. Minimum output (LSL) runs at any price, so it is the inflexible block; the MW offered above it at or below $0 can still be backed down by price but keeps running when prices go negative; and units with no offer curve run at their schedule whatever the price.
Units 60-day data
One row per resource, for the operating day or the selected hour. Click a column to sort.
Wind and solar curtailment
MW wind and solar could have produced (HSL) minus the base point SCED sent them, averaged over each hour. This is the output SCED held back, for price or for congestion. It comes from the 60-day disclosure, unit by unit. Recent days that have no 60-day data yet use an estimate from ERCOT's 2-day reports: the generation summary's base points against the top of the 2-day offer curves, since the summary no longer carries available output (HASL).
Price duration
Hourly average prices across every loaded day, highest to lowest, for the selected price location. The dot is the selected hour and the short marks are the rest of its day.