The impacts of hourly variations of large scale
wind power production in the Nordic countries
on the system regulation needs
Hannele Holttinen
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VTT TECHNICAL RESEARCH CENTRE OF FINLAND
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:
–
–
–
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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

Demand (MW)
7000
Fluctuating power production
–
Wind MW
–
6000
5000

Many scattered wind parks
–
MW
4000
3000

2000
1000
0
169
337
505
–
673
Hour (january 2000)

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smoothing out the variations
when large geographical
distribution
Production 2…40 hours ahead
can be forecasted
–
1
min-hours-days-months-years
average production of 100 MW,
varies between 0…400 MW
for scheduling and exchange
(market)
forecasting errors (regulating
market)
In-hour variations have to be
absorbed by the system
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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
Costs of integration wind power in the system
– 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
0
5
10
15
20
25
30
– the amount of flexibility in the
The amount of wind power in the system (% of yearly
system and the cost of
consumption)
increasing it
(reserves/transmission/DSM)
Cost of wind power integration - the shape of the curve
The costs of integrating wind power
in the system
–
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Interconnected Nordic market area. Data for 1999…2001

Hourly electricity consumption
–
Finm
Tro

Hourly wind power production:
–
N.
SWE
Hel
–
N-M
FIN
V-M
V-S
–
Ø-L
S.
SWE
S-L
–
–
W.DK
E.DK
–
Central
Europe
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Finland, Sweden, Norway,
Denmark East and West
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
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Large scale production of wind power (1)
Denmark January 2000, ~2 GW wind
Load
Total wind
6000
12000
5000
10000
4000
8000
3000
6000
2000
4000
1000
2000
0
0
1
169
337
hour
505
673
Load
Total wind
One wind park
14000
MW
MW
7000
–
Finland January 2000, 4 GW wind (8,2 TWh/a)
1
169
337
505
673
Hour
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.
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Large scale production of wind power (2)
Sweden January 2000, 8 GW wind (16 TWh/a)
January 2000, DK-SE-Fi à 4000 MW (25 TWh/a)
28000
45000
24000
40000
35000
20000
16000
Load
12000
Total wind
8000
One wind
park
25000
15000
10000
5000
0
0
169
337
hour
505
673
Load
Wind
20000
4000
1
–
MW
MW
30000
1
169
337
505
673
hour
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.
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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
1.00
correlation
0.80
0.60
0.40
0.20
0.00
0
100
200
300
400
distance (km)
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500
600
700
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Wind data for countries - statistics
YEAR 2000
Finland 1000 MW Sweden 1000 MW Denmark ~1000MW
Correlation to Finland 2000 MW
1,00
Correlation to Sweden 2000 MW
0,46
1,00
Correlation to Denmark MW 2000
0,32
0,76
1,00
Average production MW
235
240
242
Minimum hourly value
1
0
0
Maximum hourly value
901
939
1025
Standard Deviation
183
219
220
–
–
Nordic 1000 MW
One wind farm scaled to
239
5
873
172
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 SouthSweden 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.
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232
0
1023
261
10
Wind % cap
100 %
90 %
80 %
70 %
60 %
50 %
40 %
30 %
20 %
10 %
0%
12000
10800
9600
8400
7200
6000
4800
3600
2400
1200
0
Pori wind farm 8 MW
Demand (MW)
1
Load (MW)
wind % of capacity
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FINLAND
DurationCENTRE
curves yearOF
2000
Finland
721 1441 2161 2881 3601 4321 5041 5761 6481 7201 7921 8641
Duration:
Wind / Load
One wind farm / Total
production of 21 sites
Hour
Duration curves year 2000 Finland
Summer: Wind % cap
Summer: Load (MW)
100 %
90 %
80 %
70 %
60 %
50 %
40 %
30 %
20 %
10 %
0%
Winter: Load (MW)
1
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721
1441
2161
Hour
2881
3601
4321
12000
10800
9600
8400
7200
6000
4800
3600
2400
1200
0
Load (MW)
wind % of capacity
Winter: Wind % cap
Wind / Load
Winter / summer
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Wind power production during peak load hours
Finland, Sweden and Denmark
The
whole
year
Denmark
2000
Denmark
2001
Finland
1999
Finland
2000
S.Sweden
1999
S.Sweden
2000
FI+SE+DK
2000
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During
During
During
50 peaks 100 peaks
10 peaks
Average Average
min-max min-max
Average
min-max
Average
min-max
24.2 %
0.0-93.2 %
20.4 %
0.0-91.2 %
22.1 %
0.0-88.6 %
23.5 %
0.1-90.1 %
24.7 %
0.0-100 %
24.0 %
0.0-93.9 %
23.9 %
0.5-87.3 %
30.4 %
0.5-90.6 %
30.6 %
0.1-88.2 %
7.1 %
2.8-36.9 %
29.6 %
2.9-71.8 %
20.3 %
1.9-62.8 %
15.0 %
0.5-60.7 %
15.4 %
2.0-50.9 %
32.9 %
0.4-90.6 %
27.6 %
0.0-88.2 %
8.5 %
2.2-45.9 %
26.8 %
2.9-71.8 %
21.0 %
0.8-66.2 %
15.3 %
0.1-74.8 %
19.9 %
1.3-75.8 %
24.7 %
0.7-71.1 %
36.8 %
0.2-74.1 %
6.9 %
4.7-10.2 %
34.4 %
4.0-71.8 %
22.8 %
15.8-29.2%
14.7 %
2.8-52.4 %
13.0 %
4.8-46.5 %
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.
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VTT TECHNICAL RESEARCH CENTRE OF FINLAND
Wind power production during 10 highest peak load
hours in Finland. Years 1999 and 2000.
Finsk tid!
Load
Wind % cap
Fre 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 %


Finsk tid!
Load
Wind % cap
Tii 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 %
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.)
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Wind in the system: net load = load - wind
Denmark - load and wind power data from January 2000
14000
7000
12000
6000
10000
5000
8000
4000
MW
MW
Finland - load and upscaled wind power data from January 2000
6000
3000
4000
2000
Load
2000
0
01.01.2000


Load
Load - Wind
1000
Load - Wind (4000 MW)
0
08.01.2000
15.01.2000
Time
22.01.2000
29.01.2000
1
169
337
505
673
Hour
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
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VTT TECHNICAL RESEARCH CENTRE OF FINLAND
Variations of large scale wind power production

In one country
–
20 %
Eltra 2001 (~1900 MW)
15 %
Finland 2000 (34 MW)
10 %
–
5%
-10 %
8141
7401
6661
5921
5181
4441
3701
2961
2221
1481
-5 %
741
0%
1
Hourly variation (% of installed capacity)
Hourly variations of wind production.
Duration curve for one year (8760 hours).

In Nordic countries
–
-15 %
-20 %
–
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the maximum hourly
variation is less than 20 %
of capacity
the hourly variations are
larger than 5 % of capacity
during 7-9 % of time
the maximum hourly
variation is less than 10 %
of capacity
the hourly variations are
larger than 5 % of capacity
less than 4 % of time.
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VTT TECHNICAL RESEARCH CENTRE OF FINLAND
Variations of large scale wind power production
change in production (% of capacity)
Hourly variations of wind production in Finland year 2000 duration
70 %
60 %
50 %
40 %
30 %
20 %
10 %
0%
-10 %0 % 10 % 20 % 30 % 40 % 50 % 60 %
-20 %
-30 %
-40 %
-50 %
-60 %
-70 %
–
Finland 30.125 MW
–
Olos 3 MW
Pori 8 MW
Olos 10 min data
12 h variations:

–
70 % 80 % 90 % 100
%

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:
–
% of time
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
8.4 % of of nameplate
capacity 6 times per month,
max 11 % (Denmark)
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Year 2000 Finland
Demand (MW)
14000
Wind 4000 MW (8,2 TWh)
12000
MW
10000
8000
6000
4000
2000
0
1
721 1441 2161 2881 3601 4321 5041 5761 6481 7201 7921 8641
Hour
Finland year 2000 - hourly variations with 4000 MW wind
Hourly variation -net load
1500
Hourly variation -load
1000
-1000
-1500
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8431
7869
7307
6745
6183
5621
5059
4497
3935
3373
2811
2249
1687
1125
-500
563
0
1
MW
500
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Hourly variations together with load variations Effect to max


Wind increase
max % of cap
16 %
32 %
18 %
13 %
Wind decrease
max % cap
-17 %
-27 %
-20 %
-13 %
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.
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Load increase
max MW
1150
3230
1140
4750
Load decrease
max MW
-990
-2050
-850
-3000
variations if 10 % of
energy wind, MW
200
400
50
0
Increase in max hourly variations caused by wind, year 2000 data
change in max variation (MW)
Hourly
variations:
Finland
Sweden
Denmark
FI+SE+DK
1100
1000
900
800
700
600
500
400
300
200
100
0
-1000 %
Finland change in net load decrease
Finland change in net load increase
Sweden change in net load decrease
Sweden change in net load increase
DK change in net load decrease
DK change in net load increase
10 %
20 %
wind % of consumption
30 %
40 %
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VTT TECHNICAL RESEARCH CENTRE OF FINLAND
Hourly variations of wind vs variations of load
Eltra duration of hourly variations year 2000, wind 1350-1800 MW
Finland duration of hourly variations year 2000, wind 4000 MW
1200
load increasing
load decreasing
net load increasing
net load decreasing
wind increasing
wind decreasing
hourly variations (MW)
900
600
300
0
0%
-300
5%
10 %
15 %
20 %
25 %
load increasing
load decreasing
900
net load increasing
net load decreasing
600
hourly variations (MW)
1200
w ind increasing
w ind decreasing
300
0
0%
5%
10 %
15 %
20 %
-300
-600
-600
-900
-900
-1200
-1200
% of time
–
–
–
% of time
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
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25 %
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VTT TECHNICAL RESEARCH CENTRE OF FINLAND
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
–
–
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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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VTT TECHNICAL RESEARCH CENTRE OF FINLAND
Future work

More data:
–


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:
–
–

Norway, Denmark offshore wind power data 15.5.1999…14.5.2000
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
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