offshore grids for wind power integration - Greenpeace

GLOBAL ENERGY [R]EVOLUTION
A NORTH SEA ELECTRICITY GRID [R]EVOLUTION
In contrast, the wind power generation for the whole North Sea is very
smooth. From the distributions in Figure 24c), we can observe that:
• the maximum hourly step sizes are ±19% of installed capacity;
• only 0.43% of all hourly power variations exceed in any direction
10% of the installed capacity;
• for the 3-hourly variation this is 13.5% and for the 9-hourly one
it is 44.8%;
• again, for longer step sizes, the power variation becomes
distributed at random.
In order to summarize the overall statistics of power variations for
the three countries, P5 and P95 percentiles are given in Annex C.
In conclusion, the characteristic period for which spatial
decorrelation of wind speed can lead to a smooth generation profile
depends strongly on the size of the area over which wind farms are
distributed. In the German Bight, variability is clearly reduced for
hourly time steps and fairly well for 3-hourly steps. For the wind
farms off the British east coast, variability is clearly reduced for
hourly and 3-hourly time steps. Very long variations occur at
random in all regions.
figure 23: cumulative frequency of variations
in hourly generation FOR ONE WIND FARM, ALL WIND FARMS OFF
THE BRITISH EAST COAST AND ACCUMULATED FOR ALL OFFSHORE WIND
FARMS IN THE NORTH SEA; LEGEND: TIME LAG
Power Variation (%)
100
50
0
-50
-100
100
50
0
-50
-100
100
50
0
-50
-100
a) London Array I-IV: 1,000 MW
b) All offshore wind farms off the British coast: 22,238 MW
c) All offshore wind farms in the North Sea: 68.4 GW
0 10 20 30 40 50 60 70 80 90 100
Cumulative Frequency of Power Variations (%)
1 h 3 h 9 h 27 h
figure 22: cumulative frequency of variations
in hourly generation FOR ONE WIND FARM, ALL WIND FARMS IN
THE GERMAN BIGHT AND ACCUMULATED FOR ALL OFFSHORE WIND FARMS
IN THE NORTH SEA; LEGEND: TIME LAG
figure 24: cumulative frequency of variations
in hourly generation FOR ONE WIND FARM, ALL WIND FARMS IN
THE BELGIAN EEZ AND ACCUMULATED FOR ALL OFFSHORE WIND FARMS
IN THE NORTH SEA; LEGEND: TIME LAG
100
50
0
-50
-100
a) Bard I+II: 1,600 MW
100
50
0
-50
-100
a) Single wind farm Belgium: 300 MW
Power Variation (%)
100
50
0
-50
-100
b) All offshore wind farms in the German Bight: 26,418 MW
Power Variation (%)
100
50
0
-50
-100
b) All offshore wind farms in the Belgium: 3,846 MW
100
50
0
-50
-100
c) All offshore wind farms in the North Sea: 68.4 GW
0 10 20 30 40 50 60 70 80 90 100
100
50
0
-50
-100
c) All offshore wind farms in the North Sea: 68.4 GW
0 10 20 30 40 50 60 70 80 90 100
Cumulative Frequency of Power Variations (%)
Cumulative Frequency of Power Variations (%)
1 h 3 h 9 h 27 h
1 h 3 h 9 h 27 h
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