Lower wind, higher load pushes up gas share in ERCOT
Weaker wind output and heavier load resulted in natural-gas fired generation taking up more than half of the fuel mix in the Electric Reliability Council of Texas in July, an almost two-year high, with more nuclear outages in the footprint, the most recent ERCOT data showed.
ERCOT’s energy supply totaled over 38 TWh in July, a significant jump of nearly 13% from June’s total at 34 TWh, but almost flat with the year-ago level of 38 TWh.
Moreover, the grid operator set July daily peakload records twice, on July 20 and 28, reaching 68.8 GW and 69.5 GW, respectively, while the prior July record stood at 67.7 GW, set in 2015. July 2016’s peak was at 67.4 GW.
Natural gas-fired generation supplied 50.6% of the total demand, a level last reached in August 2015 of 51.2%, compared with 44.9% in June and 45.6% in July 2016. Natural gas has topped the fuel stack for five of the first seven months of the year, second to coal only in January and April.
Wind generation, which set a record high of supplying over a quarter in March, produced only about 10.7% in July, the lowest level so far this year.
“After a robust first half of the year for wind generation in ERCOT, a region that saw a prolific buildout of wind capacity during Q4 2016 and Q1 2017, July wind output failed to meet market expectations,” said Robert DiDona, a partner at Arlington, Virginia-based Energy Ventures Analysis. Wind output dwindled to just 10.7% of total generation for ERCOT while gas generation increased by 11% year over year, taking advantage of slightly lower delivered gas prices, DiDona said.
Nuclear power’s contribution fell over 1% month on month to 7.3% in July, down from 9.7% in July 2016 as Luminant’s 1,124-MW Comanche Peak-2 nuclear unit went offline on June 5 due to problems with a steam turbine.
