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
Floating Offshore Wind Turbines Explained
Overview of Floating Offshore Wind - National Renewable Energy Laboratory Webinar - March 17, 2020
NREL webinar diagram - March 17, 2020
floating vs. fixed bottom foundations
best offshore locations - U.S. and global
floating turbine types
turbine spacing & air turbulence
electric cable network
offshore & land-based turbine sizes
turbine, foundation, and installation costs
Overview of Floating Offshore Wind
National Renewable Energy Laboratory Webinar
March 17, 2020
Walt Musial
Principal Engineer
Offshore Wind Research Platform Lead
National Renewable Energy Laboratory
Golden, Colorado USA
Webinar video available at NREL YouTube channel.
Floating wind turbine types
(from diagram above)
Spar: stability through ballast (weight) installed below its main buoyancy tank.
Challenges -- Deep draft limit port access.
Semisubmersible: achieves static stability by distributing bouyancy widely at the water plane.
Challenges -- Higher exposure to waves; more structure above the waterline.
Tension-leg platform (TLP)
Achieves static stability through mooring line tension with a submerged bouyancy tank.
Challenges -- Unstable during assembly; high vertical load moorings.
Best global sites for offshore wind energy production
NREL webinar map - March 17, 2020
Seafloor depth and proximity to population centers are factors in offshore windplant site selection.
Most existing global offshore wind turbine generators are installed on fixed bottom support structures
> NREL webinar diagram - March 17, 2020
U.S. coastal floor depths are shallower in Atlantic and Great Lakes regions
Lighter shades of blue indicate shallower floors. U.S. Department of The Interior - Bureau of Ocean Energy Management (BOEM) regulates 15 Lease Areas (red) giving developers exclusive site control of up to 25 gigaWatts (GW) capacity. BOEM has also identified 13 Call Areas (orange) - potential wind energy areas that under public review.
NREL webinar map - March 17, 2020 (Tap/click to enlarge).
U.S. offshore windspeeds are best near NE coast, northern California and Oregon
NREL webinar map - March 17, 2020
Darker colors indicate the best potential offshore wind energy sites, where average annual windspeeds are greater than 10 meters per second (22 miles per hour). Offshore wind electric energy may double the present U.S. annual electric energy consumption.
Floating foundations are required for depths greater than 60 meters
NREL webinar map - March 17, 2020
Dark-blue areas indicate potential offshore windpower areas where floor depths are greater than 60 meters. Great Lakes offshore wind plants may require adequate distance from shore to eliminate visual impact. Lake freezing is a design concern.
Floating wind turbine components
NREL webinar map - March 17, 2020
Offshore wind turbines sizes are larger
Growth of wind turbine sizes since 1980. Green grass at bottom left half of chart indicates land-based projects. NREL webinar diagram - March 17, 2020
Undersea electric cable grid design
NREL webinar diagram - March 17, 2020
Array voltage will soon increase to 66 kiloVolts (kV) to lower cost.
Electrical array cable cost increases with turbine spacing but decrease with turbine size.
Exact turbine spacing is a trade-off between wake losses and array cable cost.
Other factors such as navigation safety may play a role.
Offshore wind project electric collection network design is similar to an onshore electric utility distribution network, but performs the opposite function. Onshore powerlines and buried cables distribute electric power from a substation to end-users. Offshore submarine cables collect electric power from wind turbine generators for delivery to a floating substation, where the voltage is boosted and the electric power is delivered to shore via submarine transmission cables.
Higher windspeeds produce more electricity
Block Island Wind entered service as the first U. S. commercial offshore wind electric generating project in 2016. NREL offshore map above shows average annual windspeed at Block Island is 9.5 - 9.75 meters per second. At this windspeed, a 6 MW wind turbine at this site generates about 3.5 MW. Periods of windspeeds greater than the annual average generate the most electricity. At rated windspeed of about 12 meters per second, power output does not exceed the 6 MW rating, as rotor blades furl to prevent overspeed.
NREL webinar chart - March 17, 2020 (Tap-click to enlarge)
Total generating capacity at Block Island Wind is 30 MW (megaWatts) The project consists of 5 fixed-bottom turbines rated 6 MW each. Location is about 3.8 miles from Block Island off the Rhode Island Coast.
Challenge: turbine size and spacing affects airflow turbulence
Simulated wake turbulence downwind of turbines. NREL webinar diagram - March 17, 2020
Wake losses are the reduction of wind turbine generated electric power due to windspeed reduction and airflow turbulence caused by an upwind turbine
NREL webinar diagram - March 17, 2020
As wind turbine heights and rotor diameters increase, spacing must also increase to compensate for turbulence and wake losses.
Challenge: floating wind turbines rock and tilt
Modified from NREL webinar diagram - March 17, 2020
Wave motion affects floating offshore wind turbine power generation. Tilting toward the wind causes net windspeed to increase at rotor height, and to decrease when tilting motion is away from way from wind.
Cost of floating wind turbine plus on-site installation
Stehly, Tyler; and Philipp Beiter. 2020. 2018 Cost of Wind Energy Review. National Renewable Energy Laboratory, Golden, Colorado. NREL/TP-5000-74598. Funding provided by the U.S. Department of Energy Office of Energy Efficiency and Renewable Energy Wind Energy Technologies Office. NREL webinar chart - March 17, 2020
NREL’s 2018 Cost of Wind Energy Review estimated turbine electric generator will be 24.3 percent of the total installed cost of floating offshore wind plants. Section 5.2 of this report explains factors which produced this estimate, including global floating offshore wind plant construction - excerpt below:
2018 Cost of Wind Energy Review (NREL)
(excerpt)
Given the relatively limited number of offshore wind projects in the United States and the lack of publicly available data, we obtained the CapEx estimates using ORCA (Beiter et al. 2016). The representative turbine characteristics (i.e., turbine capacity, rotor diameter, and hub height) used as inputs to the model were obtained from the “2018 Offshore Wind Technologies Market Report” (Musial et al. 2019). The capacity-weighted average turbine installed globally in 2018 was 5.5 MW with a 140-m rotor diameter at a 94-m hub height. We used these turbine parameters in combination with the spatial parameters presented in Table 12 for the fixed-bottom and floating reference sites to calculate CapEx.
The ORCA model yields a total installed CapEx value of $4,444/kW for the fixed-bottom reference site and $5,355/kW for the floating reference site. It should be noted that the CapEx estimates for floating offshore wind in this analysis assume a 5.5-MW turbine and are not necessarily optimized for floating offshore wind applications, therefore, they may negatively impact CapEx estimates. Progression to larger turbines is likely to coincide with deployment of commercial-scale floating wind technologies (Spyroudi 2016).
Lightning Science and Wind-Turbine Electric Generator Protection
A celltower in Switzerland is struck by lighting more than 100 times per year. Scientists collect data there which may lead to lightning-resistant wind-turbine electric generator designs.
Linecurrents composite image created from wind-turbine generators photo by Cassie Boca and lightning photo by Clinton Naik at Unsplash.com.
Lightning strikes may damage wind-turbine generators.
“Upward” lightning from structure to cloud is a recent phenomenon.
Researchers describe 21st-century “Ben Franklin” lightning-strike observations — Science Friday podcast August 16, 2019 episode.
Where There’s Thunder, There’s Lightning Science is the title of a recent Science Friday public radio program segment. Research into lightning strike characteristics such as described in the program may aid in wind turbine electric generating equipment design to reduce or prevent damage caused by lightning’s high-energy electrical discharge.
SciFri host Ira Flatow and Institute of Electrical and Electronic Engineers (IEEE) Spectrum news editor Amy Nordrum interviewed lightning science researcher Farhad Rachidi of the Swiss Federal Institute of Technology (EPFL), electrical engineering professor Bill Rison of New Mexico Tech at Socorro, and research scientist Ryan Said of Vaisala during the August 16, 2019 broadcast of Science Friday.
The 34-minute segment and is available for replay at the Science Friday website (link below), and for download at online podcast services.
EPFL scientists collect lightning-strike data from instruments installed at Säntis Tower in Switzerland, at elevation 2,502 m (8,209 ft) on Säntis mountain. Lightning strikes the tower more than 100 times per year.
New Mexico Tech’s Rison and Mark Stanley installed a custom-designed broadband interferometer, built by Stanley, on Säntis Tower to provide measurements for EPFL analysis.
The Säntis team’s work has held particular relevance for wind farm operators. That’s because most strikes recorded at the tower are examples of upward lightning—which travels from ground-to-cloud instead of cloud-to-ground. - IEEE Spectrum
Some of the Science Friday segment discussion concentrates on characteristics and physics of lightning, and research designed to gain greater understanding of lightning dynamics. Rachidi’s comments about WTGs and “upward — downward” lightning strikes begins at about 17 minutes into the audio track.
Vaisala provides weather, environment, and industrial measurements services, including the U.S. National Lightning Detection Network.
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.
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U.S. EIA Today in Energy
Tax Credit Phaseout Causes Jump In 2019 Windpower Construction
Production Tax Credit reductions began in 2019 . . . December 31, 2019 construction start deadline to qualify.
2.3 cents per kiloWatthour Production Tax Credit (PTC) reductions began in 2017
Construction must begin before December 31, 2019, to qualify for PTC.
Energy Information Administration
United States Department of Energy
May 15, 2019
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EIA expects that U.S. wind capacity additions in 2019 will total 12.7 gigawatts (GW), exceeding annual capacity additions for the previous six years but falling short of the record 13.3 GW of wind capacity added in 2012. Expected capacity additions discussed in this article are based on projects reported to EIA through surveys and reported in EIA’s Preliminary Monthly Electric Generator Inventory - May 31, 2019.
U.S. Energy Information Adminstration chart.
Changes in annual capacity additions for wind in the United States are often explained by changes to tax incentives. The U.S. production tax credit (PTC), which provides operators with a tax credit per kilowatthour of renewable electricity generation for the first 10 years a facility is in operation, was initially set to expire for all eligible technologies at the end of 2012 but was later retroactively renewed. The high level of annual capacity additions in 2012 was driven by developers scheduling project completion in time to qualify for the PTC. Similarly, the increase in annual capacity additions for wind scheduled for 2019 is largely being driven by the legislated phaseout of the PTC extension for wind.
When renewed in 2013, the PTC provided a maximum tax credit for wind generation of 2.3 cents per kilowatthour (kWh) for the first 10 years of production. Under the PTC phaseout, the amount of the tax credit decreases by 20 percentage points per year from 2017 through 2019. Facilities that begin construction after December 31, 2019, will not be able to claim the PTC.
Under the current PTC legislation, wind projects are eligible to receive credit based on either the year the project begins operation or the year in which they demonstrate that 5% of total capital cost for the project has been spent and project construction has begun. This 5% down method, known as safe harboring, enables wind developers to receive the PTC at a given year’s level, provided they complete construction no more than four calendar years after the calendar year that construction of the facility began.
U.S. wind project developers who want to receive the full 2016 value of the PTC must begin operations by the end of 2020. However, based on the latest project statuses reported on the Preliminary Monthly Electric Generator Inventory, more wind capacity is expected to come online by the end of 2019 than by the end of 2020. As in previous years, many of the annual wind capacity additions are expected to come online in the month of December. According to reported dates for wind projects coming online in 2019, 5.7 GW, or 44.7% of the annual total, are currently expected to be completed in December.