The impacts of hourly variations of large scale wind power production in the Nordic countries on the system regulation needs Hannele Holttinen

The impacts of hourly variations of large scale wind power production in the Nordic countries

on the system regulation needs

Hannele Holttinen

VTT TECHNICAL RESEARCH CENTRE OF FINLAND

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Contents

Wind power production in the Nordic countries:– Variations, smoothing of the variations when geographically

distributed generation. Correlation of wind power production

Wind power production versus load:– Wind power production during peak load hours – Variations of geographically distributed wind power production

compared to load variations. – What is the effect of large scale wind production on the electricity

system? How much wind before more flexibility is needed in the system? How much more flexibility (reserves, transmission, DSM) when wind power increases?


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Large scale production of wind power Fluctuating power production

– min-hours-days-months-years – average production of 100 MW,

varies between 0…400 MW Many scattered wind parks

– smoothing out the variations when large geographical distribution

Production 2…40 hours ahead can be forecasted

– for scheduling and exchange (market)

– forecasting errors (regulating market)

In-hour variations have to be absorbed by the system

0

1000

2000

3000

4000

5000

6000

7000

1 169 337 505 673

Hour (january 2000)

MW

Demand (MW)

Wind MW


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How much wind power can electricity system absorb? => How much does the integration cost?

– The extra costs of integration depend on wind penetration

– X % without extra costs, variations of load will absorb the variations of wind.

– XX % with prediction tools, changes in scheduling, changes in transmission (export/import)

– > YY % with increasing extra costs for integration

– The extra costs of integration depend on electricity system

– the amount of flexibility in the system and the cost of increasing it (reserves/transmission/DSM)

Costs of integration wind power in the system

0 5 10 15 20 25 30

The amount of wind power in the system (% of yearly consumption)

Th

e c

os

ts o

f in

teg

rati

ng

win

d p

ow

er

in t

he

sy

ste

m

Cost of wind power integration - the shape of the curve


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Hourly electricity consumption– Finland, Sweden, Norway,

Denmark East and West Hourly wind power production:

– Finland: 54 turbines, 21 sites (10 areas scaled to 100 MW each).

– Sweden: 13 turbines, 4 sites (3 areas scaled to 100 MW each).

– Denmark: real production of 1800…2300 MW in year 2000, East and West total wind production.

– Norway: so far only one site– Geographically well dispersed for

Denmark and Finland– Only 4 sites in Sweden, upscaling

will overestimate variations

Interconnected Nordic market area. Data for 1999…2001

FIN

N.SWE

S.SWE

W.DK

E.DK

Central Europe

Finm

Hel

N-M

Ø-L

S-L

V-M

V-S

Tro


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Large scale production of wind power (1)

– Consumption and wind power production in January 2000: Denmark is real data (~12% wind), for Finland and Sweden data from wind parks is scaled up to about 10 % of yearly electricity consumption from wind.

Denmark January 2000, ~2 GW wind

0

1000

2000

3000

4000

5000

6000

7000

1 169 337 505 673

hour

MW

LoadTotal wind

Finland January 2000, 4 GW wind (8,2 TWh/a)

0

2000

4000

6000

8000

10000

12000

14000

1 169 337 505 673

HourM

W

Load Total windOne wind park


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Large scale production of wind power (2)

– January 2000 data: Finland, one wind park average power ~1500 MW varies between 0…4000 MW, for total wind average 1500 MW, 30…3500 MW. For 3 Nordic countries: average 4500 MW, 200...9800 MW.

Sweden January 2000, 8 GW wind (16 TWh/a)

0

4000

8000

12000

16000

20000

24000

28000

1 169 337 505 673

hour

MW Load

Total wind

One windpark

January 2000, DK-SE-Fi à 4000 MW (25 TWh/a)

0

5000

10000

15000

20000

25000

30000

35000

40000

45000

1 169 337 505 673

hourM

W

Load Wind


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Correlations inside a country

Sweden: – 2 sites in Gotland, correlation 0.8– Gotland vs Southern Sweden: correlation 0.5…0.7

Finland:Correlation of hourly wind production in Finland, 1999

0.00

0.20

0.40

0.60

0.80

1.00

0 100 200 300 400 500 600 700

distance (km)

corr

ela

tion


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Wind data for countries - statistics

– Correlation of wind data: If wind production data is not correlated, there can be strong winds in one place at the same time as weaker in another, and together the time series will be smoother. The Finnish and Norwegian wind production is only weakly correlated to that in South-Sweden and Denmark. The winds in South-Sweden and Denmark are correlated.

– Descriptive statistics: The average, maximum and minimum production of wind power production scaled to 1000 MW from Finland/Sweden/Denmark and the whole of the 3 countries are seen. The standard deviation tells about the variability of the hourly time series. As a comparison, data from one wind farm scaled up to 1000 MW is shown.

YEAR 2000 Finland 1000 MW Sweden 1000 MW Denmark ~1000MW Nordic 1000 MW One wind farm scaled to 1000MWCorrelation to Finland 2000 MW 1,00 Correlation to Sweden 2000 MW 0,46 1,00Correlation to Denmark MW 2000 0,32 0,76 1,00Average production MW 235 240 242 239 232Minimum hourly value 1 0 0 5 0Maximum hourly value 901 939 1025 873 1023Standard Deviation 183 219 220 172 261


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Duration:

Wind / LoadOne wind farm / Total production of 21 sites

Wind / Load Winter / summer

Duration curves year 2000 Finland

0 %10 %

20 %30 %

40 %50 %60 %

70 %80 %

90 %100 %

1 721 1441 2161 2881 3601 4321

Hour

win

d %

of c

ap

aci

ty

01200

24003600

480060007200

84009600

1080012000

Lo

ad

(M

W)

Summer: Wind % cap

Winter: Wind % cap

Summer: Load (MW)

Winter: Load (MW)

Duration curves year 2000 Finland

0 %10 %

20 %30 %

40 %50 %60 %

70 %80 %

90 %100 %

1 721 144121612881 36014321504157616481720179218641

Hour

win

d %

of c

ap

aci

ty

01200

24003600

480060007200

84009600

1080012000

Lo

ad

(M

W)

Wind % cap

Pori wind farm 8 MW

Demand (MW)


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Wind power production during peak load hoursFinland, Sweden and Denmark

Wind power production during the 10, 50 and 100 highest peak load hours compared to the average production.

All numbers: wind power production as % of installed capacity (nameplate capacity). Hourly maximum and minimum values also shown.

Thewholeyear

During

10 peaks

During50 peaks

During100 peaks

Averagemin-max

Averagemin-max

Averagemin-max

Averagemin-max

Denmark2000

24.2 %0.0-93.2 %

24.7 %0.7-71.1 %

30.4 %0.5-90.6 %

32.9 %0.4-90.6 %

Denmark2001

20.4 %0.0-91.2 %

36.8 %0.2-74.1 %

30.6 %0.1-88.2 %

27.6 %0.0-88.2 %

Finland1999

22.1 %0.0-88.6 %

6.9 %4.7-10.2 %

7.1 %2.8-36.9 %

8.5 %2.2-45.9 %

Finland2000

23.5 %0.1-90.1 %

34.4 %4.0-71.8 %

29.6 %2.9-71.8 %

26.8 %2.9-71.8 %

S.Sweden1999

24.7 %0.0-100 %

22.8 %15.8-29.2%

20.3 %1.9-62.8 %

21.0 %0.8-66.2 %

S.Sweden2000

24.0 %0.0-93.9 %

14.7 %2.8-52.4 %

15.0 %0.5-60.7 %

15.3 %0.1-74.8 %

FI+SE+DK2000

23.9 %0.5-87.3 %

13.0 %4.8-46.5 %

15.4 %2.0-50.9 %

19.9 %1.3-75.8 %


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Wind power production during 10 highest peak load hours in Finland. Years 1999 and 2000.

January 1999 had lower wind speeds than average (production index 71 %). January 2000 had higher wind speeds than average (production index 112 %). (Production index=

calculated production of selected sites compared to average production in January of 11 years 1985…1995. Finnish Meteorological Institute.)

Finsk tid! Load Wind % capTii 25.01.2000 08:00 11829 30.98 %Tii 25.01.2000 07:00 11724 27.91 %Per 21.01.2000 17:00 11652 65.70 %Maa 24.01.2000 22:00 11642 7.48 %Tii 25.01.2000 09:00 11632 29.45 %Per 21.01.2000 08:00 11628 71.75 %Per 21.01.2000 18:00 11602 58.59 %Tii 25.01.2000 10:00 11597 34.88 %Maa 24.01.2000 08:00 11552 3.98 %Tii 25.01.2000 17:00 11532 12.81 %

Finsk tid! Load Wind % capFre 29.01.1999 09:00 13083.0 8.19 %Fre 29.01.1999 18:00 13022.0 6.19 % To 28.01.1999 18:00 12964.0 6.55 % To 28.01.1999 20:00 12936.0 6.92 %Fre 29.01.1999 11:00 12935.0 4.80 % To 28.01.1999 19:00 12923.0 6.87 % To 28.01.1999 23:00 12915.0 10.17 %Fre 29.01.1999 08:00 12915.0 8.71 %Fre 29.01.1999 19:00 12914.0 6.24 %Fre 29.01.1999 12:00 12853.0 4.72 %


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Wind in the system: net load = load - wind

Large scale wind power production changes the scheduling of the rest of the production system

Load pattern well known and studied - prediction models for wind power needed, research still going on

Finland - load and upscaled wind power data from January 2000

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12000

14000

01.01.2000 08.01.2000 15.01.2000 22.01.2000 29.01.2000

Time

MW

Load

Load - Wind (4000 MW)

Denmark - load and wind power data from January 2000

0

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1 169 337 505 673

Hour

MW

Load

Load - Wind


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Variations of large scale wind power production

In one country – the maximum hourly

variation is less than 20 % of capacity

– the hourly variations are larger than 5 % of capacity during 7-9 % of time

In Nordic countries – the maximum hourly

variation is less than 10 % of capacity

– the hourly variations are larger than 5 % of capacity less than 4 % of time.

Hourly variations of wind production. Duration curve for one year (8760 hours).

-20 %

-15 %

-10 %

-5 %

0 %

5 %

10 %

15 %

20 %

1

74

1

14

81

22

21

29

61

37

01

44

41

51

81

59

21

66

61

74

01

81

41

Hou

rly v

aria

tion

(% o

f in

stal

led

capa

city

)

Eltra 2001 (~1900 MW)

Finland 2000 (34 MW)


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Variations of large scale wind power production

12 h variations: – max ± 95 % of nameplate

capacity (Germany, ISET) – max ± 84..92 % of capacity

(Finland) Hourly variations:

– max ± 20 % of nameplate capacity (Germany, Denmark, Finland)

15 min variations: – 8.4 % of of nameplate

capacity 6 times per month, max 11 % (Denmark)

Hourly variations of wind production in Finland year 2000 - duration

-70 %

-60 %

-50 %

-40 %

-30 %

-20 %

-10 %

0 %

10 %

20 %

30 %

40 %

50 %

60 %

70 %

0 % 10 % 20 % 30 % 40 % 50 % 60 % 70 % 80 % 90 % 100%

% of time

cha

ng

e in

pro

du

ctio

n (

% o

f ca

pa

city

) Finland 30.125 MW

Olos 3 MW

Pori 8 MW

Olos 10 min data


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Finland year 2000 - hourly variations with 4000 MW wind

-1500

-1000

-500

0

500

1000

1500

1

563

1125

1687

2249

2811

3373

3935

4497

5059

5621

6183

6745

7307

7869

8431

MW

Hourly variation -net load

Hourly variation -load

Year 2000 Finland

0

2000

4000

6000

8000

10000

12000

14000

1 721 1441 2161 2881 3601 4321 5041 5761 6481 7201 7921 8641

Hour

MW

Demand (MW)

Wind 4000 MW (8,2 TWh)


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Hourly variations together with load variations

The need for regulating power in the system increases if wind production causes larger variations to the system than the variations in load today. The short term variations were studied by hourly time series.

This is a preliminary result based on only year 2000 data. Denmark: relatively greater load variations absorb the wind variations. Sweden: data from 4 sites is not representative when scaled up.

Increase in max hourly variations caused by wind, year 2000 data

-1000

100200300400500600700800900

10001100

0 % 10 % 20 % 30 % 40 %

wind % of consumption

cha

ng

e in

ma

x va

ria

tion

(M

W) Finland change in net load decrease

Finland change in net load increaseSweden change in net load decreaseSweden change in net load increaseDK change in net load decreaseDK change in net load increase

Hourly variations:

Wind increase max % of cap

Wind decrease max % cap

Load increase max MW

Load decrease max MW

Effect to max variations if 10 % of

energy wind, MWFinland 16 % -17 % 1150 -990 200Sweden 32 % -27 % 3230 -2050 400Denmark 18 % -20 % 1140 -850 50FI+SE+DK 13 % -13 % 4750 -3000 0


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Hourly variations of wind vs variations of load

– Large amount of turbines in small geographic area (Eltra) – Larger geographic area with a small number of turbines (Finland), data

upscaled to make 10 % energy penetration – Wind has considerably less effect on net load variations when using real

data with large amount of turbines and when initial load variations large

Eltra duration of hourly variations year 2000, wind 1350-1800 MW

-1200

-900

-600

-300

0

300

600

900

1200

0 % 5 % 10 % 15 % 20 % 25 %

% of time

ho

url

y va

riat

ion

s (M

W)

load increasing

load decreasingnet load increasing

net load decreasingwind increasing

wind decreasing

Finland duration of hourly variations year 2000, wind 4000 MW

-1200

-900

-600

-300

0

300

600

900

1200

0 % 5 % 10 % 15 % 20 % 25 %

% of time

ho

url

y va

ria

tion

s (M

W)

load increasing

load decreasing

net load increasing

net load decreasing

w ind increasing

w ind decreasing


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Conclusions from first results of hourly data analysis

An effort to estimate the increase in regulation needs for large scale wind power production:

– Comparing the hourly load variations without wind to the variations after large scale wind production: hourly variations of net load vs load

– Wind production data upscaled --> over estimate the variations– Only 1-2 years of data for each country, Norway still missing

Result: 10 % of wind would increase the need of flexibility by 200 MW in Finland, 50 MW in Denmark, 0 MW in the Nordic area

– This applies if no bottlenecks of transmission– In Denmark much less effect of wind to net load variations, because

wind is well dispersed, production all over Denmark and because in Denmark load variations are considerably higher than in Sweden and Finland


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Future work

More data:– Norway, Denmark offshore wind power data 15.5.1999…14.5.2000

Probabilistic method of combining the variations of wind and load More statistical analyses:

– persistence of production, duration of calms, diurnal distribution of variations (load-wind-net load)

Comparisons with other weather related production forms:– CHP: heat load, temperature correlation of wind.– Hydro and solar power

Longer term variations of wind (4-12-24-36 hours):– wind power in the electricity market, performance of prediction methods

Documents

The impacts of hourly variations of large scale wind power production in the Nordic countries on the system regulation needs Hannele Holttinen