Predictable solar, unpredictable wind: Colo & Wyo hourly electric supply - June 16-30, 2021
Photo: Western Area Power Administration
Charts below depict hourly data supplied to the U.S. Energy Information Administration (EIA) by two Balancing Authorities which monitor electric power supply and demand in Colorado and Wyoming:
Western Area Power Administration (WACM)
Rocky Mountain Region, Loveland CO
Public Service Company of Colorado (PSCO)
Denver CO (Xcel Energy)
Colorado and Wyoming electric supply are combined in this report. The WACM Balancing Authority includes most of Colorado and Wyoming. WACM hourly electricity generation data supplied to EIA by Western Area Power Administration does separate Colorado and Wyoming. Therefore, charts below show results for both States
The role of Balancing Authorities is described at Colorado and Wyoming hourly electric power - June 1-15, 2021. A map of WACM and PSCO Balancing Authority territories is also available at the same site.
Daily electric consumption peaked 3 - 6 PM
Figure 1 (below) shows hourly totals of electric megaWatthours generated from all energy sources to supply the consumption demand of electric consumers in Colorado and most of Wyoming. These energy sources are:
wind turbines
solar panels
combustion natural gas and coal power plants
hydroelectric dams
other, such as biogas methane
A daily pattern of maximum electric generation in late afternoon and early evening is consistent through the June 16-30, 2021 period.
Figure 1: Hourly electric generation from all sources for Colorado and Wyoming: June 16-30, 2021. Linecurrents.live chart, U.S. Energy Information Administration (EIA) data.
Windpower - no daily pattern
Daily wind-generated electric power was present each day July 16 - 31, 2021. Maximum output periods were not consistent. Windpower increased during the morning rise in consumer electric consumption demand on 4 days, and increased 7 days during the late-afternoon peak. <Fig. 2 below>
Fig. 2: Hourly wind electric generation - Colorado and Wyoming: June 16-30, 2021. Linecurrents.live chart, U.S. EIA data.
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June 20 is an example of wind electric generation increasing during the late-afternoon and early-evening high demand period. Solar electric generation declined in the middle of the late afternoon peak demand period. <Fig. 3 below>
Fig. 3: Hourly wind, solar and total electric generation - Colorado and Wyoming: June 20, 2021. Linecurrents.live chart, U.S. EIA data.
. . .
June 27 is an example of wind electric generation decreasing during the late-afternoon and early-evening maximum consumption demand period. <Fig. 4 below>
Fig. 4: Hourly wind, solar and total electric generation - Colorado and Wyoming: June 27, 2021. Linecurrents.live chart, U.S. EIA data.
Solar electric performs best in the morning
Solar electric consistently increased during the morning rise in consumer demand each day. Afternoon solar electric was variable. Late afternoon solar declines coincide with the start of the daily maximum consumption demand period. <Fig. 5 below>
Fig. 5: Hourly solar electric generation - Colorado and Wyoming: June 16-30, 2021. Linecurrents.live chart, U.S. EIA data.
High daily temperatures boosted electricity demand
Summer heat caused electric power generated to increase in response to higher consumer consumption. Charts below compare Denver CO maximum daily temperature to regional daily maximum electric demand and total daily electric energy consumption.
June 20, 21, 26 and 27 were days of lower electric demand and consumption. Solar electric generation was also lower (Fig. 5) on these days, suggesting partial cloudcover may have accompanied cooler temperatures in the region.
Fig. 6: Daily maximum demand - Colorado and Wyoming. Denver daily maximum temperatures. June 16-30, 2021. Linecurrents.live chart, U.S. EIA data.
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Fig. 7: Daily total megaWatthours - Colorado and Wyoming. Denver daily maximum temperatures. June 16-30, 2021. Linecurrents.live chart, U.S. EIA data.