The Use and Value of Climate Information for Wind Power Planning

Bret HarperAugust 9, 2005

SOARS® ProgramUniversity Corporation for Atmospheric Research

Boulder, CO

The StorylineThe coming energy transformationResearch questionsClimatology and wind power analysisENSO’s effects on power production

The Time For an Energy Transformation Is Now!

(or maybe long overdue)Driving forces and threats:

Persistent local/regional air pollution (Davis 2002)

Volatile oil and gas prices (Hall 2005)

Economic and security risks (O’Brien and Leichenko 2000, Barnett 2001)

High levels of investment are required for a transformation of energy infrastructure50-100 years are needed for transformation of energy infrastructure

Northern Great Plains58% of US onshore wind resource (AWEA 2004)

Diversifying US electric power resource Wind power development is an opportunity for economic revitalization

Agricultural economy is in decline due to:

MechanizationGlobalizationGround water shortages

Wind Energy Potential

Northern GreatPlains

Southern GreatPlains

West

East

Integrating Wind into Electricity Grids

Wind power planning has focused on short-term forecastingMore attention is needed on long-term climate variability that will influence weather patterns Wind turbines and substation.

(AWEA 2004)

The Challenge of Matching Electricity Demand and Supply

Generating plantsTransmissionWeather patterns TV pickupsChanges in wind speeds

Diversified sourceWeather ForecastsClimate Information

AWEA 2004

Weather Forecasting and Climate Information

Good weather forecasts and climate information are crucial to the future of the wind power industry

Hourly weather forecasts are necessary to participate in deregulated energy market

Climate information is important to estimating the long-term capacity for energy production and economic returns on the infrastructure investments

Critical IssueENSO effects:

TemperaturePrecipitationSnowfallTornado activityPeak wind gustWind power production

Research Questions

from: Renewable Resource Data Center

1. Do periods of ENSO impact the characteristics of wind in the Northern Great Plains?

2. How can climate information be best used for planning:

the future electric grid supply operations, andthe potential for wind energy penetration.

ApproachNCDC TD6421 Enhanced Hourly Wind Station Data for the Contiguous United States

Huron Airport Pierre AirportEllsworth AFB Rapid City Airport

49 yr of hourly data1950-1999 > 1.7 million hours

High resolution map of South Dakota’s wind energy resource (NREL).

Divide into 3 sets (SST in Nino 3.4 region)

16 El Nino phases27 Neutral phases11 La Nina phases

Listings of El Nino and La Nina events after 1950 as defined by SST's in the Nino 3.4 region and exceeding + 0.40C threshold.

The starting and ending month of each is given with the duration in months.

El Nino events La Nina events

Begin End Duration Begin End Duration

Aug-51 Feb-52 7 Mar-50 Feb-51 12

Mar-53 Nov-53 9 Jun-54 Mar-56 22

Apr-57 Jan-58 15 May-56 Nov-56 7

Jun-63 Feb-64 9 May-64 Jan-65 9

May-65 Jun-66 14 Jul-70 Jan-72 19

Sep-68 Mar-70 19 Jun-73 Jun-74 13

Apr-72 Mar-73 12 Sep-74 Apr-76 20

Aug-76 Mar-77 8 Sep-84 Jun-85 10

Jul-77 Jan-78 7 May-88 Jun-89 14

Oct-79 Apr-80 7 Sep-95 Mar-96 7

Apr-82 Jul-83 16 Jul-98 Dec-99 18

Aug-86 Feb-88 19

Mar-91 Jul-92 17

Feb-93 Sep-93 8

Apr-97 Apr-98 13      

1940 1945 1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000

050

100

150

Summary of Sixty Years of Wind Speed Data at Huron

NORDEX N60

Power Curve

0

200

400

600

800

1000

1200

1400

1600

0 10 20 30

Wind speed [m/s]

Po

we

r [k

W]

Power 1,300 kW

Diameter 60 m

197 ft

Rotor speed 12.8/19.2 rpm

Hub height 80 m

262 ft

Ellsworth Huron

Average Daily Power Production by Phase

-- neutral

-- cold

-- warm

Annual Power Production by Phase

PierreRapid City

-- neutral

-- cold

-- warm

Ellsworth Huron

Month Month

Ellsworth Huron

Rapid City PierreP

roba

bili

ty o

f a

low

win

d ev

ent

Pro

babi

lity

of

a lo

w w

ind

even

t

Month Month

Results

An ENSO-wind relationship exists

Higher wind energy production is expected during La Nina periods due to less frequent lull episodes.

El Nino periods are characterized by lower mean wind speeds and more frequent occurrences of lulls that will reduce the capacity for energy production.

Future WorkDetailed analysis of SD data

Confidence intervalsStatistical significance

Examine ENSO impacts on wind characteristics for all US locations that are potential wind power sitesExplore potential impacts of other types of systematic climate variability on winds (e.g., PDO, NAO, AO)

Final WordsClimate is crucial for long-term wind power site selection, the estimation of expected capacity for power production, and estimating requirements for energy storage and complementary sources.Wind development is crucial to future energy supply development in the US

Cost effective energy Environmental benefits

AcknowledgementsScience mentor: Robert HarrissCommunication mentor: David GochisStatistics: Rick KatzAlso: Larry McDaniel, Claudia Tebaldi, Casey Thornbrugh, and the rest of the SOARS protégés and staff

ReferencesAWEA, 2004: Wind Energy Potential. Wind Web Tutorial, www.awea.orgBarnett, Jon; 2001: Security and Climate Change. Tyndall Centre Working Paper No. 7. Davis, Devra; 2002: When Smoke Ran Like Water.Hall, Kevin G.; 2005: Simulated oil meltdown shows U.S. economy’s vulnerability. Knight Ridder Newspapers.IEA, 2005: Integrating Wind into Electricity Grids. Variability of Wind Power and other Renewable Management Options and Strategies, IEA report.O’Brien, Karen L. and Leichenko, Robin M.; 2000: Double exposure: assessing the impacts of climate change within the context of economic globalization. Global Environmental Change.Trenberth, K.E.; Caron, J.M.; Stepaniak, D.P.; Worley, S.; 2002: J. Geophys. Res. 107, 10.1029/2000JD000298.

The wind doesn't blow all the time. How much can it really contribute to a utility's generating capacity? How much energy can wind realistically supply to the U.S.?What is needed for wind to reach its full potential in the U.S.?How much energy can wind supply worldwide?I've heard that Denmark is pulling back on wind development. Does that mean wind is a failure?What is the "energy payback time" for a wind turbine? What are your primary references?

Questions

El Nino/La NinaStorm Tracks

El Nino tends to bewet during winter

La Nina tends to bedry during winter

La Na Da: Neutraltends to flip/flopdepending on cycle

QuestionsWhat is ENSO?What is a wind turbine and how does it work? How big is a wind turbine? How much electricity can one wind turbine generate?How many turbines does it take to make one megawatt (MW)? How many homes can one megawatt of wind serve? What is "capacity factor"? If a wind turbine's capacity factor is 33%, doesn't that mean it is only running one-third of the time? What is "availability factor"?

Results

Huron daily profile

24 hour

x 10

-1 m

/s

Huron annual profile

x 10

-1 m

/s

Month

Ellsworth Pierre

Ellsworth Huron

kWkW kW

kW

0 = cold phase 1 = neutral phase 2 = warm phase

The wind doesn't blow all the time. How much can it really

contribute to a utility's generating capacity?

Utilities prefer on/off plantsWind plants increase probability system will meet demandCapacity factor*capacity ~ capacity value

E.g. 100-MW wind (35%) ~ 35-MW conventionalE.g. 2001 CPUC

162-MW wind (30%) ~ 48-MW

http://www.eere.energy.gov/windpoweringamerica/pdfs/xcel_wind_decision.pdf

THE TOP TWENTY STATES for Wind Energy Potentialas measured by annual energy potential in the

billions of kWh, factoring in environmental and land use exclusions for wind class of 3 and higher.

B kWh/Yr B kWh/Yr

1 North Dakota 1,210 11 Colorado 481

2 Texas 1,190 12 New Mexico 435

3 Kansas 1,070 13 Idaho 73

4 South Dakota 1,030 14 Michigan 65

5 Montana 1,020 15 New York 62

6 Nebraska 868 16 Illinois 61

7 Wyoming 747 17 California 59

8 Oklahoma 725 18 Wisconsin 58

9 Minnesota 657 19 Maine 56

10 Iowa 551 20 Missouri 52

Source: An Assessment of the Available Windy Land Area and Wind Energy Potential in the Contiguous United States, Pacific Northwest Laboratory, August 1991. PNL-7789

Total = 10,470

What is needed for wind to reach its full potential

in the U.S.? Consistent policy support

Large lay-offsHold up investments

Nondiscriminatory access to transmission linesPenalty for failure to transmit on scheduleNew penalty system needed for wind

New transmission linesHigh voltage lines from High Plains to population centersExpense offset by benefit to

consumers national security

How much energy can wind supply worldwide? Currently

More than 39,000-MW worldwide90 B kWh

9 million American homesDozen large nuclear power plants

Theoretically5,800 quadrillion BTUs

15 times current world energy production1 quad

172 million barrels oil45 million tons coal

I've heard that Denmark is pulling back on wind

development. Does that mean wind is a failure?

Denmark is small, the U.S. is not20% of demand in Denmark, 0.4% of demand in U.S.Half the size of Indiana

Denmark has transformed its national power system, the U.S. has not

Overproduction causes scrambling to increase exportsUnimaginable in U.S.

Danish wind plants are typically small, U.S. wind plants are not.

Community involvement and low-capacity distribution networksLarge wind turbines require advance transmission planning and no affect on customer network

What is the "energy payback time" for a wind

turbine? The net energy value of a wind turbine or other power plant

i.e. how long the plant has to operate to generate the amount of electricity that was needed for its manufacture and construction

Shortest energy payback time of any energy technology

3 – 8 months

What is ENSO?

What is a wind turbine and how does it work?

Courtesy of Penn State Erie, The Behrend College

1981 1985 1990 1996 1999 2000

Rotor (meters)

10 17 27 40 50 71

Rating (kW)

25 100 225 550 750 1650

Annual MWh

45 220 550 1480 2200 5600

Back

How many turbines does it take to make one megawatt (MW)?1 MW = 1,000 kW = 1 million

W

500 kW – 4 MW turbines

Valmont Station = 226 MW

How many homes can one megawatt of wind serve?

The plants . . . have added 200,000 megawatts of electricity generation capacity nationwide, which would power 200 million homes – The Blade (Toledo, OH) June 12, 2005 1 MW ~ 1,000 homes100 MW wind farm ~ 30,000 homes

30% capacity factor1,000 MW coal plant ~ 750,000 homes

75% capacity factor

What is "capacity factor"?  Actual amount of power produced over time

Capacity Factor =                                            

 Power that would have been produced if

turbine operated at maximum output 100% of the time

100 MW wind farm ~ 30 MW30% capacity factor

1,000 MW coal plant ~ 750 MW75% capacity factor

NoMidwest: 65-80%< full capacityCapacity factor lower

If a wind turbine's capacity factor is 33%, doesn't that mean it is only running one-third of the time?

What is "availability factor"?A measurement of the reliability of

a power plantModern wind turbine >98%

NREL 2002

Modern coal plant ~ 85%Northwest Power Planning Council 2002