Increased solar-generation has precipitated an added need for natural gas-fired generation between 4 p.m. and 6 p.m. to meet California power demand, according to a new U.S. Energy Information Administration analysis.
In those 2020 summer months when the daily solar generation accounted for between 30 and 40 percent of total generation between 10 a.m. and 2 p.m., natural gas-based generation increased by between 2.5 and 4.5 GWh. The agency based this on data from its Hourly and Daily Balancing Authority Operations Report.
The agency said there were several days this summer when the California ISO and other balancing authorities needed on average 3.7 GW more natural gas fired generation between 4 p.m. and 6 p.m. It said that for several days in the summer of 2020, "more than 5.5 GW of natural gas-fired capacity ramped up between 4:00 p.m. and 6:00 p.m. to meet higher-than-average peak demand."
Meanwhile, Western daytime power prices diverged in Oct. 29 through Nov. 5 trading.
California daytime power prices jumped between $15 and as much as $23.55/MWh by Nov. 5. South of Path 15 gained the most value, adding $23.55 to end at $62.90/MWh. Pacific Northwest prices tumbled by between $3.25 and $8.70. Mid-Columbia peak power lost the most value, down $8.70 to $24.70/MWh.
Off-peak power values followed a similar pattern. South of Path 15 nighttime power added $7.35 to $43.40/MWh while Mid-Columbia fell $10.60 to $21.05/MWh
CAISO demand reached 29,490 MW Nov. 5, which should be the week's high.
Total renewables on the CAISO grid reached 11,336 MW Oct. 30, supplying almost 42 percent of demand. Solar resources contributed 9,119 MW that same day, accounting for about 34 percent of demand. Thermal generation sources contributed 19,690 MW or roughly 66.5 percent of Nov. 5 demand.
Natural gas prices in the West lost value by the end of trading. Sumas natural gas lost the most, down 77 cents to $3.03/MMBtu. SoCal CityGate proved the exception, adding 77 cents after a $2.22 Thursday-to-Tuesday leap, ending at $4.39/MMBtu.
Henry Hub natural gas values dropped 34 cents to $2.66/MMBtu.
National working natural gas in storage was 3,919 Bcf as of Oct. 30, according to the EIA. This is a net decrease of 36 Bcf compared to the previous week.
In October, the average high peak price at Henry Hub was $3.07/MMBtu, 42 cents greater than in 2019 (see "Price Trends").
SoCal Border and Malin natural gas hub prices each gained 55 cents year over year, while PG&E CityGate natural gas added $1.06 to $4.26/MMBtu.
Average Western peak power prices for October generally increased compared to the year prior. Palo Verde added the most year over year, up $61 to $105.25/MWh. Mid-Columbia values tumbled $2.65 year over year to $51.65/MWh.