Windpower rallied most evenings with peak-time performance
Sunny with a good chance of wind . . . Colorado-Wyoming hourly & daily electric power supply . . . August 1-15, 2021
Colorado-Wyoming hourly & daily electric power supply
August 1-15, 2021
Coors Field in Denver CO at sunset. Time when stadium lights turn on August evenings is near the end or after the daily electric consumption peak in Colorado & Wyoming. Photo by Owen Lystrup on Unsplash.
solar electric mostly steady 8 AM - 4 PM
wind electric better overnights, late afternoons & evenings . . . mostly calm mid’-days
consumers’ daily electric consumption highs 4 - 7 PM
Hourly electric generating data by energy source for only Colorado or Wyoming are not available for public viewing as of the date of this report. See Appendix for details.
U.S. Energy Information Administration hourly electric generating data is the source for charts and tables in this report. Generated power in the Colorado and Wyoming combined area is assumed to approximately equal consumers’ aggregated consumption. Exchanges by utilities and Balancing Authorities with neighboring U.S. States and regions are not included in the results shown here.
Generators fueled by natural gas and coal produced nearly three-fourths of the electricity in Colorado and Wyoming combined in the first half of August 2021. <Figs. 1 and 2>
Fig. 1: Electric generation percent of total by energy source for Colorado and Wyoming: August 1-15, 2021. Linecurrents.live chart, U.S. Energy Information Administration (EIA) data. Tap/click to enlarge.
Fig. 2: Electric generation megaWatt-hours (MWhr) by energy source for Colorado and Wyoming: August 1-15, 2021. Linecurrents.live chart, U.S. EIA data.
A daily pattern of maximum electric generation from all energy sources in late afternoon and early evening was consistent through the August 1-15, 2021 period. <Fig. 3>
EIA data contains unexplained deviations:
August 11 - 10 AM
- spike: WACM hydroelectric
August 13 - 7 PM
- drop: WACM hydroelectric
Fig. 3: Hourly electric generation from all energy sources for Colorado and Wyoming: August 1-15, 2021. Linecurrents.live chart, U.S. EIA data.
Colorado & Wyoming
Hourly Generation
Maximum & Minimum
August 1-15, 2021
Generation |
MWhr |
Date |
|---|---|---|
____________ |
_______ |
_________ |
maximum |
14,145 |
Aug 09 |
|
|
5-6 PM |
minimum |
7,344 |
Aug 01 |
|
|
1-2 AM |
Windpower climbed during evening peak demand frequently
Late-afternoon and early evening windpower increases to support aggregated consumer’s daily peak consumption demands 10 of 15 days: August 2, 3, 5, 6, 7, 8, 9, 11, 14 and 15.
Mid-day declines in windpower supply were common August 1-15. <Fig. 4>
Fig. 4: Hourly wind electric generation - Colorado and Wyoming: August 1-15, 2021. Linecurrents.live chart, U.S. EIA data.
Daily wind electric energy totals were not consistent. The highest daily total was 6-times greater than the lowest. <Fig. 5>
Fig. 5: Daily wind electric generation - Colorado and Wyoming: August 1-15, 2021. Linecurrents.live chart, U.S. EIA data.
Colorado & Wyoming
Daily Windpower
Maximum & Minimum
August 1-15, 2021
Windpower |
MWhr |
Date |
|---|---|---|
_____________ |
_________ |
________ |
maximum |
62,805 |
Aug 14 |
minimum |
10,221 |
Aug 01 |
average |
37,281 |
|
Solid solar electric daily pattern
Solar electric generation performed similar to July 2021. Declines in late afternoon result in little or no solar electric supplied during daily 4-7 PM peak electric consumption periods. <Fig. 6>
Fig. 6: Hourly solar electric generation - Colorado and Wyoming: August 1-15, 2021. Linecurrents.live chart, U.S. EIA data.
Solar energy supplied more than 5,000 megaWatt-hours daily for all but 3 days. <Fig. 7>
Fig. 7: Daily solar electric generation - Colorado and Wyoming: August 1-15, 2021. Linecurrents.live chart, U.S. EIA data.
Colorado & Wyoming
Daily Solar Energy
Maximum & Minimum
August 1-15, 2021
Solar |
MWhr |
Date |
|---|---|---|
____________ |
________ |
_________ |
maximum |
6,874 |
Aug 05 |
minimum |
4,740 |
Aug 15 |
average |
5,997 |
|
Hourly windpower vs. consumer demand
Example: windpower greatest when needed least
August 4 is an example of more wind electric generation overnight, and less during daylight hours. <Fig. 8>
Fig. 8: Hourly wind, solar and total electric generation - Colorado and Wyoming: August 4, 2021. Linecurrents.live chart, U.S. EIA data.
Example: windpower nearly matches demand
August 7 is an example of wind electric generation 24-hour pattern nearly synchronized with aggregated consumers’ consumption demand. <Fig. 9>
Fig. 9: Hourly wind, solar and total electric generation - Colorado and Wyoming: August 7, 2021. Linecurrents.live chart, U.S. EIA data.
APPENDIX
Electric power generated in Colorado and most of Wyoming supplies the consumption demand of electric consumers in these States. Some electric capacity is exchanged with Balancing Authorities and electric utilities in adjoining States.
Electric generating sources include:
wind turbines
- solar PV panels
- natural gas combustion powerplants
- coal combustion powerplants
- hydroelectric dams
- pumped hydroelectric storage
- other, such as biogas methane
Charts in this report created from 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
Rocky Mountain Region (WACM)
Loveland CO
Public Service Company of Colorado
(PSCO)(Xcel Energy)
Denver CO
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.
Consistent solar, erratic wind for CO-WY 2nd half July 2021 electric power supply
Coal and natural gas combustion generated the most electric power.
Colorado-Wyoming hourly & daily electric power supply
July 16-31, 2021
Western Area Power Administration photo
consumers’ consumption demand peaked late-afternoon & early evening peak
windpower lowest 6 - 9 AM
solar electric consistent most days
hot days not always cause of higher electric demand
Hourly electric generating data by energy source for Colorado or Wyoming individually are not available for public viewing as of the date of this report. See Appendix for details.
U.S. Energy Information Administration hourly electric generating data is the source for charts and tables in this report. Generated power in the Colorado and Wyoming combined area is assumed to approximately equal consumption. Exchanges by utilities and Balancing Authorities with neighboring U.S. States and regions are not included in the results shown here.
Generators fueled by natural gas and coal produced nearly three-fourths of the electricity in Colorado and Wyoming combined for the second half of July 2021. <Figs. 1 and 2>
Fig. 1: Electric generation percent of total by fuel type for Colorado and Wyoming: July 16-31, 2021. Linecurrents.live chart, U.S. Energy Information Administration (EIA) data. Tap/click to enlarge.
Fig. 2: Electric generation MegawattHours (MWhr) from all sources for Colorado and Wyoming: July 16-31, 2021
Late afternoon & early evening are daily peak electric demand periods
A daily pattern of maximum electric generation from all energy sources in late afternoon and early evening was consistent through the July 16-31, 2021 period. <Fig. 3>
Fig. 3: Hourly electric generation from all energy sources for Colorado and Wyoming: July 16-31, 2021. Linecurrents.live chart, U.S. EIA data.
Colorado and Wyoming
Hourly Generation
Maximum & Minimum
July 16 - 31, 2021
Generation |
MWhr |
Date |
|---|---|---|
____________ |
_______ |
_________ |
maximum |
14,556 |
Jul 20 |
|
|
5-6 PM |
minimum |
8,022 |
Jul 27 |
|
|
4-5 AM |
Windpower: no daily high/low cycle
Windpower hourly mimimums occurred 7-8 AM most days, a few hours after the daily mimimum demand. <Fig. 4>
Only one windpower maximum occurred mid-’day: July 24. Maximums in the 5-7 PM hours on the 16th and 25th helped supply the evening peak demand.
Fig. 4: Hourly wind electric generation - Colorado and Wyoming: July 16-31, 2021. Linecurrents.live chart, U.S. EIA data.
Wind-generated power supplied the Colorado - Wyoming electric grid each day July 16-31, 2021. Production was less than 30,000 MegaWatthours (MWhrs) on July 18 and 19. <Fig. 5>
Fig. 5: Daily wind electric generation - Colorado and Wyoming: July 16-31, 2021. Linecurrents.live chart, U.S. EIA data.
Colorado and Wyoming
Windpower
Maximum & Minimum
July 16 - 31, 2021
Windpower |
MWhr |
Date |
|---|---|---|
_____________ |
_________ |
________ |
maximum |
66,635 |
Jul 20 |
minimum |
22,592 |
Jul 18 |
average |
41,260 |
|
Solar electric: consistent
Solar electric generation performed steadily for most of the second half of July 2021. <Fig. 6>
Fig. 6: Hourly solar electric generation - Colorado and Wyoming: July 16-31, 2021. Linecurrents.live chart, U.S. EIA data.
Total daily output was below 5,000 MWhr only on July 24 and 31. <Fig. 7>
Fig. 7: Daily solar electric generation - Colorado and Wyoming: July 16-31, 2021. Linecurrents.live chart, U.S. EIA data.
Colorado-Wyoming
Solar Energy
Maximum & Minimum
July 16-31, 2021
Solar |
MWhr |
Date |
|---|---|---|
____________ |
________ |
_________ |
maximum |
7,283 |
Jul 18 |
minimum |
4,389 |
Jul 24 |
average |
6,156 |
|
Solar, wind and consumption demand peak times compared
Example: windpower supported daily demand peak
July 20 is an example of solar electric generation declining as consumers’ demand reached daily maximum. Wind electric generation climbed in synchronism with consumption demand. <Fig. 8>
Fig. 8: Hourly wind, solar and total electric generation - Colorado and Wyoming: July 20, 2021. Linecurrents.live chart, U.S. EIA data.
Example: windpower belated recovery
July 27 is an example of wind electric generation remaining flat during the first half of the late-day peak consumption demand period. <Fig. 9>
Fig. 9: Hourly wind, solar and total electric generation - Colorado and Wyoming: July 27, 2021. Linecurrents.live chart, U.S. EIA data.
Higher temperatures not reliable predictor of electric demand
Electric demand and consumption did not always track Denver CO maximum daily temperatures. <Fig. 10 and 11>
Denver weather history is selected to represent Colorado and Wyoming conditions, as it is the largest concentration of electric power consumption in the two-state region.
Fig. 10: Daily maximum demand and Denver daily maximum temperatures. July 16-31, 2021. Linecurrents.live chart, U.S. EIA data.
Fig. 11: Daily total electric energy and Denver daily maximum temperatures. July 16-31, 2021. Linecurrents.live chart, U.S. EIA data.
APPENDIX
Electric power generated in Colorado and most of Wyoming supplies the consumption demand of electric consumers in these States. Some electric capacity is exchanged with Balancing Authorities and electric utilities in adjoining States.
Electric generating sources include:
wind turbines
- solar PV panels
- natural gas combustion powerplants
- coal combustion powerplants
- hydroelectric dams
- pumped hydroelectric storage
- other, such as biogas methane
Charts in this report created from 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
Rocky Mountain Region (WACM)
Loveland CO
Public Service Company of Colorado
(PSCO)(Xcel Energy)
Denver CO
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.
Solar electric output tapers-off during daily maximum electric demand
Colorado-Wyoming pattern seen in June 2021 continued in July - late afternoon rise in electric demand while solar energy dropped.
Colorado-Wyoming daily electric power supply
July 1-15, 2021
electric generation highest in late-afternoon & early evening to supply consumers’ consumption demand
windpower produced no daily pattern
solar daily electric declined during evening peak consumption periods
hot days caused electric generation to increase in response to higher electric consumption
Electric power generated in Colorado and most of Wyoming supplies the consumption demand of electric consumers in these States. Some electric capacity is exchanged with Balancing Authorities and electric utilities in adjoining States.
Electric generating sources include:
wind turbines
solar panels
combustion natural gas and coal power plants
hydroelectric dams and pumped hydro storage
other, such as biogas methane
- - -
Hourly electric generating data by energy source for Colorado-alone are not available for public viewing as of the date of this report. See Appendix for details.
Daily peak electric demand consistent at 3 - 7 PM
Fig. 1: Hourly electric generation from all sources for Colorado and Wyoming: July 1-15, 2021. Linecurrents.live chart, U.S. Energy Information Administration (EIA) data. Tap/click to enlarge.
A daily pattern of maximum electric generation in late afternoon and early evening was consistent through the July 1 - 15, 2021 period. <Fig. 1>
Variable windpower with no daily high/low cycle
Fig. 2: Hourly wind electric generation - Colorado and Wyoming: July 1-15, 2021. Linecurrents.live chart, U.S. EIA data.
Daily maximum windpower output periods did not follow a pattern. Some days show little wind electric production until the late-afternoon and early evening peak demand period. <Fig. 2>
Daily wind-generated electric power was present each day July 1-15, 2021, but production was low on July 4, 5, 7, 11 and 15. <Fig. 3>
Fig. 3: Daily wind electric generation - Colorado and Wyoming: July 1-15, 2021. Linecurrents.live chart, U.S. EIA data.
Colorado and Wyoming
Windpower Stats
July 1 - 15, 2021
Windpower |
MWhr |
Date |
|---|---|---|
_____________ |
_________ |
________ |
maximum |
56,562 |
Jul 08 |
minimum |
16,043 |
Jul 11 |
average |
38,387 |
|
Solar electric supply mostly stable, with two poor days
Fig. 4: Hourly solar electric generation - Colorado and Wyoming: Junly 1-15, 2021. Linecurrents.live chart, U.S. EIA data.
Solar electric generation performed steadily for most of the first half of July 2021. <Fig. 4>
Total daily output reached a maximum of 7,338 MWhr on July 7, and was below 3,500 MWhr only on July 13 and 14. <Fig. 5>
Fig. 5: Daily solar electric generation - Colorado and Wyoming: July 1-15, 2021. Linecurrents.live chart, U.S. EIA data.
Colorado-Wyoming
Solar Energy Stats
July 1-15, 2021
Solar |
MWhr |
Date |
|---|---|---|
____________ |
________ |
_________ |
maximum |
7,388 |
Jul 07 |
minimum |
2,917 |
Jul 14 |
average |
5,620 |
|
Solar declined during the daily peak electric demand
Wind sometimes picked-up
July 7 is an example of solar electric generation declining as consumers’ demand reached daily maximum. Wind electric generation was minimal for the first half of the consumption peak. <Fig. 6>
Fig. 6: Hourly wind, solar and total electric generation - Colorado and Wyoming: July 7, 2021. Linecurrents.live chart, U.S. EIA data.
Mixed results
Fig. 7: Hourly wind, solar and total electric generation - Colorado and Wyoming: July 10, 2021. Linecurrents.live chart, U.S. EIA data.
July 10 is an example of both wind electric generation remaining flat during the first half of the late-day peak consumption demand period. <Fig. 7>
90+ degree F days caused higher electric demand
Electric consumption mostly tracked Denver CO maximum daily temperatures. July 3, 4, and 6 were exceptions. <Fig. 8 and 9>
Two days were hotter than most, causing electric demand and consumption to increase in the Colorado-Wyoming region:
99ºF - July 8
95ºF - July 9
Fig. 8: Daily maximum demand - Colorado and Wyoming. Denver daily maximum temperatures. July 1-15, 2021. Linecurrents.live chart, U.S. EIA data.
Fig. 9: Daily total megaWatthours - Colorado and Wyoming. Denver daily maximum temperatures. July 1-15, 2021. Linecurrents.live chart, U.S. EIA data.
APPENDIX
Charts in this report created from 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.
Top photo by Manny Becerra on Unsplash.com
Predictable solar, unpredictable wind: Colo & Wyo hourly electric supply - June 16-30, 2021
A look at the impact of high summer temperatures on regional electric demand, and wind + solar electric generation’s performance during hot days.
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.
. . .
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.
. . .
Fig. 7: Daily total megaWatthours - Colorado and Wyoming. Denver daily maximum temperatures. June 16-30, 2021. Linecurrents.live chart, U.S. EIA data.
Colorado & Wyoming hourly electric power - June 1-15, 2021
Reliable sunny mornings started the daily solar electric generating cycle. . . . Erratic wind conditions did not produce a consistent daily wind electric pattern.
Map: Colorado and Wyoming utility-scale windpower sites, electric transmission lines, and Balancing Authorities.(1), (2)
Reliable sunny mornings started the daily solar electric generating cycle.
Erratic wind conditions did not produce a consistent daily wind electric pattern.
Two Balancing Authorities monitor Colorado’s electric power supply, as shown in the map above:
Western Area Power Administration - Loveland Area Office (WACM)
Public Service Company of Colorado (Xcel Energy - PSCO)
The U.S. Energy Information Administration (EIA) explains the role of Balancing Authorities:
A balancing authority ensures, in real time, that power system demand and supply are finely balanced. This balance is needed to maintain the safe and reliable operation of the power system. If demand and supply fall out of balance, local or even wide-area blackouts can result.
Balancing authorities maintain appropriate operating conditions for the electric system by ensuring that a sufficient supply of electricity is available to serve expected demand, which includes managing transfers of electricity with other balancing authorities. Balancing authorities are responsible for maintaining operating conditions under mandatory reliability standards issued by the North American Electric Reliability Corporation(3) and approved by the U.S. Federal Energy Regulatory Commission(4) and, in Canada, by Canadian regulators.
EIA collects the data for the Hourly Electric Grid Monitor(5) from its Form EIA-930, Hourly and Daily Balancing Authority Operations Report, which includes hourly electricity demand, forecast demand, net generation, and interchange data. The data are provided by the 65 electricity balancing authorities that operate the electric grid in the Lower 48 states and maintain real-time balance between electricity demand and supply on the grid.
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.
Electric energy generated to supply consumer demand follows a daily pattern
Figure 1 (below) shows hourly totals of electric megaWatthours generated from all energy sources for Colorado and most of Wyoming. These electric energy sources are:
wind turbines
solar panels
combustion natural gas and coal power plants
hydroelectric dams
other, such as biogas methane
Figure 1: Hourly electric generation from all sources for Colorado and Wyoming: June 1-15, 2021. Linecurrents.live chart. (Data glitch: June 2 at 3 PM)
A daily pattern of least electric generation before dawn and maximum generation during late afternoon and early evening was consistent for the first half of June 2021 in Colorado and Wyoming.
Hourly total electric generation approximately equals total consumer demand. Colorado electric utilities have little battery capacity to store variable mid'-day solar or overnight windpower for use during peak consumption hours.
Keeping electric generating supply in balance with consumer demand is required to keep the U.S. electric grid spinning at 60 Hertz (Hz, cycles per second). Excess generation causes this alternating current (AC) frequency to increase, a condition called overfrequency. Not enough generation causes a frequency reduction: underfrequency.
Since wind and solar electric supplies are variable, combustion power plants compensate for changes in solar/wind output and consumers’ demand by increasing or decreasing the fuel supply.
Windpower supply - some days good, some not
Daily wind-generated electric power was inconsistent July 1 - 15, 2021. Six days show morning increases beginning 2 - 3 hours after consumer demand climbed. Evening performance was better, as windpower output increased before or during evening consumption peaks in all but 3 days. <Fig. 2 below>
Fig. 2: Hourly wind electric generation - Colorado and Wyoming: June 1-15, 2021. Linecurrents.live chart.
Windpower increased in late afternoon . . . or not
An example of beneficial wind conditions was June 12, as electric power generated by Colorado and Wyoming wind turbines increased in the evening concurrently with the total electricity generated to supply to consumers’ demand. Solar electric generation dropped 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 12, 2021. Linecurrents.live chart.
. . .
Wind conditions were not favorable for electric generation on June 11, when wind turbine output decreased as consumer demand increased. <Fig. 4 below>
Fig. 4: Hourly wind, solar and total electric generation - Colorado and Wyoming: June 11, 2021. Linecurrents.live chart.
Solar electric daily pattern: sunny, with a few afternoon clouds
Solar electric increased concurrently with the total electric generating supplied to consumers in early morning hours. Late-morning and afternoon declines reduced solar electric ability to support the late-afternoon peak demand in 7 days. <Fig. 5 below>
Fig. 5: Hourly solar electric generation - Colorado and Wyoming: June 1-15, 2021. Linecurrents.live chart. (Data glitch: June 2 at 3 PM)
REFERENCES
Western Interconnection Balancing Authorities - January 5, 2017 map, Western Electricity Coordinating Council
U.S. Energy Information Administration Energy Atlas Electricity Energy Infrastructure and Resources
U.S. Energy Information Administration EIA launches redesigned Hourly Electric Grid Monitor with new data and functionality
$125.5 Million Solar Technologies R&D Funding Opportunity Announced by US-DOE
DOE describes the categories of Photovoltaic (PV) and Concentrating Solar Power (CSP) research & development proposals which will qualify for grant funds. Linecurrents reviews two CSP generating stations which were US Department of Energy loan guarantee recipients in the last decade.
North section of a 200 kiloWatt (KW) community solar site near Norwood, Colorado. The February 5, 2020 US DOE solar energy research & development funding opportunity includes PV and CSP projects which advance innovative and novel ideas. Linecurrents photo.
Funding opportunities for:
photovoltaic and concentrating solar power (CSP) hardware
manufacturing
microgrid integration
agricultural co-location
artificial intelligence
innovative small projects
- - - -
History of 2 US DOE-supported CSP generating stations reviewed: Crecent Dunes & Ivanpah.
Below are excerpts of a February 5, 2020 announcement by the Solar Energy Technologies Office (SETO) of the United States Department of Energy (DOE) -- Office of Energy Efficiency and Renewable Energy (EERE).
February 5, 2020
Washington, DC
Funding will support advancements in the following areas:
Photovoltaics (PV) Hardware Research
$15 million for 8-12 projects that aim to extend PV system lifetimes and reduce hardware costs of solar systems made of silicon solar cells, as well as new technologies like thin-film, tandem, and perovskite solar cells.Integrated Thermal Energy Storage and Brayton Cycle Equipment Demonstration (Integrated TESTBED
$39 million for 1-2 projects that will develop a test site to accelerate the commercialization of supercritical carbon dioxide power cycles, a key component of low-cost concentrating solar power plants.
Falling Particle Tower - Example of Supercritical Carbon Dioxide (sCO2) Concentrating Solar Power system. Image: Mehos, Turchi, Vidal, et al, Concentrating Solar Power Gen3 Demonstration Roadmap, NREL/TP-5500-67464, January 2017. Energy.gov.
Solar Energy Evolution and Diffusion Studies 3 (SEEDS 3)
$10 million for 6-8 projects that will examine how information flows to stakeholders to enable more efficient decision-making about solar and other emerging technologies, such as energy storage.Innovations in Manufacturing: Hardware Incubator
$14 million for 7-9 projects that will advance innovative product ideas from a prototype to a pre-commercial stage, with an aim for products that support a strong U.S. solar manufacturing sector and supply chain.Systems Integration
$30 million for 7-11 projects that will develop resilient community microgrids to maintain power during and restore power after man-made or natural disasters, improve cybersecurity for PV inverters and power systems, and develop advanced hybrid plants that operate collaboratively with other resources for improved reliability and resilience.Solar and Agriculture: System Design, Value Frameworks, and Impacts Analysis
$6.5 million for 4-6 projects that will advance the technologies, research, and practices necessary for farmers, ranchers, and other agricultural enterprises to co-locate solar and agriculture.Artificial Intelligence Applications in Solar Energy with Emphasis on Machine Learning
$6 million for 8-12 projects that encourage partnerships between experts in AI and solar industry stakeholders to develop disruptive solutions across the value chain of the solar industry.Small Innovative Projects in Solar (SIPS): PV and Concentrated Solar Power (CSP)
$5 million for 15-20 projects that advance innovative and novel ideas in PV and CSP that can produce significant results within the first year of performance.
Supercritical CO2 CSP:
more efficient for converting sunlight into electric energy
Excerpts from US Department of Energy - energy.gov. Full list of references at end of this report.
- - - - -
Supercritical carbon dioxide (sCO2) power cycles have the potential to reduce the cost of concentrating solar power (CSP) by far more efficiently converting high-temperature solar heat into electricity.
When carbon dioxide (CO2) is held above its critical temperature and pressure, it acts like a gas yet has the density of a liquid. In this supercritical state, small changes in temperature or pressure cause dramatic shifts in density - making sCO2 a highly efficient working fluid to generate power.
The Solar Energy Technologies Office pursues dramatic cost reductions in technologies to make solar electricity available to all Americans. Next-generation CSP system designs use sCO2 turbine power cycles to more efficiently convert solar thermal energy to electricity and reduce the cost of CSP technology.
Three DOE Offices (Nuclear Energy, Fossil Energy, and Energy Efficiency and Renewable Energy - SETO) are working together to reduce the technical hurdles and support foundational research and development of sCO2 power cycles.
Because sCO2 power cycles work best at very high temperatures and under intense pressure, a CSP system needs receivers and heat exchangers that can withstand these conditions. Heat exchangers contribute up to 60%−70% of the total cost of a CSP sCO2 turbine system, so low-cost, highly efficient exchangers are necessary to help make CSP cost-competitive.
Benefits of CO2 CSP
Potential to increase maximum temperature of the heat transfer media to <1,000 deg C .
Well-suited for scalability to 10-100 MWe power tower systems.
Reduces water consumption compared to current Rankine process.
Makes smaller, more dispatchable power plants cost viable.
Reduces capital costs by increasing the efficiency of converting sunlight into energy.
Nevada CSP powerplant supported by US DOE loan guarantee risks bankrupcty
Crescent Dunes Concentrating Solar Energy Project near Tonapah, Nevada. Electrical generating capacity is 110 megaWatts (MW). U.S. Department of Energy photo.
Excerpts from US Department of Energy - energy.gov. Full list of references at end of this report.
- - - - -
In power tower concentrating solar power systems, a large number of flat, sun-tracking mirrors, known as heliostats, focus sunlight onto a receiver at the top of a tall tower. A heat-transfer fluid heated in the receiver is used to heat a working fluid, which, in turn, is used in a conventional turbine generator to produce electricity. Some power towers use water/steam as the heat-transfer fluid. Other advanced designs are experimenting with high temperature molten salts or sand-like particles to maximize the power cycle temperature.
. . . Crescent Dunes features a solar receiver that sits atop a tower and absorbs sunlight from over 10,000 mirrors. These mirrors follow the sun over the course of a day and magnify the sun’s power 1,200 times, heating molten salt to high temperatures. This molten salt circulates through the tower and is then used to heat a steam cycle that generates electricity. The plant also features an automated system that controls the flow of molten salt to the receiver.
. . . the molten salt heats more than 60 million pounds of salt each day to reach a consistent 1,050 degrees Fahrenheit. The salt continually circulates in a loop, enabling its reuse by storing it in tanks for use at a later time.
. . . the plant’s energy storage integration delivers solar energy captured during the day to the grid during the late afternoon and evening when the demand for power is at its highest.
. . . Since the molten salt absorbs 90% of the solar energy it receives and is used as both a heat transfer fluid and a storage medium, the plant is highly efficient. Crescent Dunes also eliminates reliance on fossil fuels as a backup energy source, enabling solar to operate as baseload generation and reliably deliver peak-period electricity to more than 75,000 homes in Nevada.
. . . Crescent Dunes is the first deployment of solar power tower technology in the United States that uses molten salt as a primary heat transfer fluid. The heat absorbed by the salt can be stored and produce electricity when required. This enables the plant to generate clean, renewable power during times when direct sunlight is not available. The innovative molten salt storage allows the project to generate power at full load on call (dispatched) for up to 10 hours without any sunlight.
In November 2015, Crescent Dunes successfully reached commercial operation and every year delivers 110 MW of electricity, plus 1.1 gigawatt-hours of storage under a 25-year power purchase agreement with NV Energy, the largest utility in Nevada.
- End of excerpts -
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Owner sues US DOE and plant operator, utility cancels contract
The US Department of Energy finalized a $737 million loan guarantee to Tonopah Solar Energy, LLC to develop the Crescent Dunes Solar Energy Project in September 2011. The site is 14 miles northwest of Tonopah, Nevada on land leased from the Bureau of Land Management - U.S. Interior Department.
Contractual and legal problems developed for Crescent Dunes in October 2019. The Las Vegas Review-Journal reported that Crescent Dunes owner SolarReserve sued the U.S. Department of Energy and plant operator Tonopah Solar Energy. SolarReserve claims in its lawsuit that US-DOE’s takeover of Tonopah's Board of Managers leaves SolarReserve without board representation, and no voice in decisions such as bankruptcy proceedings, according to reports from multiple energy news sources, including Newsdata.com.
Electric utility NV Energy terminated its 25-year contract to purchase electricity generated at Crescent Dunes October 4, 2010 - (Newsdata.com). The NV Energy - Crescent Dunes Power Purchase Agreement would was to have expired in 2040 - (Mineral County Independent-News). Electricity generated at Crescent Dunes cost NV Energy about $135 per megaWatthour - , (13.5 cents per kiloWatthour) compared with less than $30 per MWh today at a new Nevada photovoltaic solar farm, according to January 6, 2020 report by - (Bloomberg Green). Crescent Dunes had been shutdown since April 2019.
Mojave Desert CSP generating since 2013
Ivanpah Solar Electric Generating Station - Mojave Desert, California. Electrical generating capacity is up to 400 megawatts (February 2017 data). US Department of Energy image.
Ivanpah CSP quick facts
Federal loan guarantees
US Department of Energy issued three loan guarantees for $1.6 billion in total to finance Ivanpah, April 2011.
Generating Capacity
| Unit | MW | |
|---|---|---|
| Ivanpah 1 | 126 | |
| Ivanpah 2 | 133 | |
| Ivanpah 3 | 133 | |
| Total | 392 |
Electric utility power purchasers
Pacific Gas & Electric (PG&E) and Southern California Edison.
Energy storage capacity
None.
Land area
3,500 acres on federal land managed by the Bureau of Land Management.
Towers height
459 ft
Number of Heliostats
173,500
Heliostat description
Each heliostat consists of two mirrors.
Receiver type
Solar receiver steam generator.
Receiver inlet temperature
480 F
Receiver outlet temperature
1050 F
Wildlife habitat support (videos)
Bird acoustical deterrent.
Desert tortoise population analysis, juvenile relocation.
- see Stewardship of Natural Resources at Ivanpah videos
More info:
US DOE: Energy 101: Concentrating Solar Power video
US DOE: $125.5 million Funding Opportunity Announcement
US DOE: CSP sCO2 R&D description
US DOE: CSP sCO2 Brayton Cycle description
US DOE: list of Offices with links
US DOE: EERE Success Story - Crescent Dunes concentrating solar power tower
US DOE: Crescent Dunes loan guarantee info
US DOE: Power Tower System Concentrating Solar Power Basics
Las Vegas Review-Journal: Tonapah solar plant could end up in bankruptcy
PV Magazine USA.com: Will DOE take the Crescent Dunes solar project into bankruptcy?
Newsdata.com: SolarReserve Sues DOE, Says Board Takeover 'Improper' as Loan Defaults
Bloomberg Businessweek: A $1 Billion Solar Plant Was Obsolete Before It Ever Went Online
Mineral County Independent-News: NV Energy sends termination notice to massive Tonopah solar project
US DOE: Ivanpah CSP loan guarantee info
National Renewable Energy Lab (NREL): Ivanpah Solar Electric Generating System stats
Brightsource: Ivanpah CSP overview
NRG: Exploring Ivanpah: Its Power and Its People, (videos)
Greenbiz.com: 4 reasons the Ivanpah plant is not the future of solar
Colorado Electric Energy Scorecard
2017, 2018 and 2019-YTD trends for Colorado’s electric energy supply.
A pictorial review of year-to-year recent trends through May 2019.
Natural gas-combustion, wind-powered, and solar electric energy are increasing, coal-fired generation is declining.
Linecurrents related reports:
Electric energy generated by coal combusttion in Colorado through May 2019 totalled 10,230 gigaWathours (GWhr) — 462 GWhr and 4.7% greater than the same period in 2018.
First Time: U.S. Renewable Electricity Exceeded Coal-Fired Generation in April 2019
Predicted to be a short-lived trend, as windpower declines and consumer electricity demand increases in Summer.
US Energy Information Administration graph.
Big month for wind and hydroelectric output.
Less combustion fuel for power generation needed due to lower consumer electricity demand in Spring months.
U.S. Energy Information Administration
June 26, 2019
In April 2019, U.S. monthly electricity generation from renewable sources exceeded coal-fired generation for the first time based on data in EIA’s Electric Power Monthly. Renewable sources provided 23% of total electricity generation to coal’s 20%. This outcome reflects both seasonal factors as well as long-term increases in renewable generation and decreases in coal generation. EIA includes utility-scale hydropower, wind, solar, geothermal, and biomass in its definition of renewable electricity generation.
In the United States, overall electricity consumption is often lowest in the spring and fall months because temperatures are more moderate and electricity demand for heating and air conditioning is relatively low. Consequently, electricity generation from fuels such as natural gas, coal, and nuclear is often at its lowest point during these months as some generators undergo maintenance.
Record generation from wind and near-record generation from solar contributed to the overall rise in renewable electricity generation this spring. Electricity generation from wind and solar has increased as more generating capacity has been installed. In 2018, about 15 gigawatts (GW) of wind and solar generating capacity came online.
Wind generation reached a record monthly high in April 2019 of 30.2 million megawatthours (MWh). Solar generation - including utility-scale solar photovoltaics and utility-scale solar thermal - reached a record monthly high in June 2018 of 7.8 million MWh and will likely surpass that level this summer.
Seasonal increases in hydroelectric generation also helped drive the overall increase in renewable generation. Conventional hydroelectric generation, which remains the largest source of renewable electricity in most months, totaled 25 million MWh in April. Hydroelectric generation tends to peak in the spring as melting snowpack results in increased water supply at downstream generators.
U.S. coal generation has declined from its peak a decade ago. Since the beginning of 2015, about 47 GW of U.S. coal-fired capacity has retired, and virtually no new coal capacity has come online. Based on reported plans for retirements, EIA expects another 4.1 GW of coal capacity will retire in 2019, accounting for more than half of all anticipated power plant retirements for the year.
According to forecasts in EIA’s latest Short-Term Energy Outlook, coal will provide more electricity generation than renewables in the United States for the remaining months of 2019. On an annual average basis, EIA expects that coal will provide more electricity generation in the United States than renewables in both 2019 and 2020, but it expects renewables to surpass nuclear next year.
More info:
U.S. EIA Today in Energy
Colorado Wind+Solar Electric Energy: 2018 Combined
Wind and solar electric energy supply is least when Colorado consumer demand is greatest.
Utility-scale windturbine electric generators supplied 9-times more electric energy than solar sources in 2018.
Variable wind & solar monthly energy production was out-of-sync with ups-and-downs of Colorado consumers’ Spring & Summer demand.
Colorado Wind and Solar 2018 Electric Energy Production Compared
Colorado’s utility-scale solar electric energy sites generated 1,0897.3 gigaWatthours (GWhrs) in 2018. (Figure 1)
Utility-scale windpower sites supplied 9,795.5 GWhrs. (Figure 1)
- Notes -
The following are equal amounts of electric energy:
1 gigaWatthour
GWhr
1,000 megaWatthours
MWhrs
1,000,000 kiloWatthours
KWhrs
Figure 1: Linecurrents chart, US Energy Information Administration (EIA) data. Tap/click to enlarge.
Wind and Solar Electric Energy Monthly Comparison:
Colorado 2018
Windturbines generated the most electric energy in Winter and Spring. A reduction in February 2018 may be due to fewer days in the month. (Figure 2)
Wind turbine electric energy - highest months
December
1,026.4 GWhrMarch
997.9 GWhrApril
989.9 GWhr
Solar electric generating sites performed best in Summer months. (Figure 2)
Solar electric energy - highest months
June
127.9 GWhrAugust
113.1 GWhrJuly
112.2 GWhr
Figure 2: Linecurrents chart, US Energy Information Administration (EIA) data. Tap/click to enlarge.
Wind+Solar and Total Power Supply: Colorado 2018 - Monthly
Wind and solar electric energy generating sources supplied about one-fourth of Colorado utility consumers’ needs in April 2018, when 12-month electric energy consumption was least and wind/solar combined production was greatest (Figures 3 & 4):
April
4,063 GWhr total supply
1,092 GWhr wind/solar
Combined wind and solar electric energy output declined in July. In the same month, total power supply generated from all sources to meet Colorado consumers’ needs reached annual maximum. July solar/wind energy combined production supplied only one-seventh of the total Colorado power requirement (Figures 3 & 4).
July
5,494 GWhr total supply
773 GWhr wind/solar
Figure 3: Linecurrents chart, US Energy Information Administration (EIA) data. Tap/click to enlarge.
Figure 4: Linecurrents chart, US Energy Information Administration (EIA) data. Tap/click to enlarge.
How much more solar electric energy is needed to equal windpower?
If Colorado’s 2018 utility-scale solar electric energy supply is increased to nine-times actual, annual solar electric energy nearly equals wind electric energy (Figure 5).
Wind energy
9,795.5 GWhr9X Solar
9,758.7 GWhr
Figure 5: Linecurrents chart, US Energy Information Administration (EIA) data. Tap/click to enlarge.
Will a big increase in solar electric sync-up with July maximum consumers’ needs?
More solar energy generating sites would have reduced the load on fossil-fuel power generation, but not solve the wind/solar July dip. (Figure 6: Wind + 9X Solar - gray line).
In April, when consumers’ electric power demand is lowest, Wind + 9X Solar electric energy combination in a balanced wind/solar power scenario grows to nearly half of the month’s power supply requirement.
Figure 6: Linecurrents chart, US Energy Information Administration (EIA) data. Tap/click to enlarge.