Operational and Reliability Analysis of Offshore Wind Farms Has availability gone with the wind? Christopher J. Crabtree, Durham University, UK EWEA 2012 17 th April 2012
Jan 19, 2016
Operational and Reliability Analysis of Offshore Wind Farms
Has availability gone with the wind?
Christopher J. Crabtree, Durham University, UK
EWEA 2012
17th April 2012
Wind in the UK
• Operational Capacity– Onshore: 4.25 GW– Offshore: 1.52 GW
• Under Construction or Consented– Onshore: 5.37 GW– Offshore: 3.92 GW
• Planned– Onshore: 7.66 GW– Offshore: 2.28 GW
• Round 3 Offshore: up to 25 GW
Capacity Factor and Cost of Energy
• Average capacity factor:– Onshore (DECC) = 27.3%– Round 1 offshore = 29.5%– Expected offshore = 35.0%
• Average cost of energy:– Onshore (2006) = £47 per MWh– Round 1 offshore = £69 per MWh
• What might be affecting capacity factor and cost of energy?
Availability0
10
20
30
40
50
60
70
80
90
100
Jul-0
4A
ug-0
4Se
p-04
Oct
-04
Nov
-04
Dec
-04
Jan-
05Fe
b-05
Mar
-05
Apr
-05
May
-05
Jun-
05Ju
l-05
Aug
-05
Sep-
05O
ct-0
5N
ov-0
5D
ec-0
5Ja
n-06
Feb-
06M
ar-0
6A
pr-0
6M
ay-0
6Ju
n-06
Jul-0
6A
ug-0
6Se
p-06
Oct
-06
Nov
-06
Dec
-06
Jan-
07Fe
b-07
Mar
-07
Apr
-07
May
-07
Jun-
07Ju
l-07
Aug
-07
Sep-
07O
ct-0
7N
ov-0
7D
ec-0
7Ja
n-08
Feb-
08M
ar-0
8A
pr-0
8M
ay-0
8Ju
n-08
Jul-0
8A
ug-0
8Se
p-08
Oct
-08
Nov
-08
Dec
-08
Jan-
09Fe
b-09
Mar
-09
Apr
-09
May
-09
Jun-
09Ju
l-09
Aug
-09
Sep-
09O
ct-0
9N
ov-0
9D
ec-0
9
Capa
city F
acto
r (%
)
0
10
20
30
40
50
60
70
80
90
100
Jul-0
4A
ug-0
4Se
p-04
Oct
-04
Nov
-04
Dec
-04
Jan-
05Fe
b-05
Mar
-05
Apr
-05
May
-05
Jun-
05Ju
l-05
Aug
-05
Sep-
05O
ct-0
5N
ov-0
5D
ec-0
5Ja
n-06
Feb-
06M
ar-0
6A
pr-0
6M
ay-0
6Ju
n-06
Jul-0
6A
ug-0
6Se
p-06
Oct
-06
Nov
-06
Dec
-06
Jan-
07Fe
b-07
Mar
-07
Apr
-07
May
-07
Jun-
07Ju
l-07
Aug
-07
Sep-
07O
ct-0
7N
ov-0
7D
ec-0
7Ja
n-08
Feb-
08M
ar-0
8A
pr-0
8M
ay-0
8Ju
n-08
Jul-0
8A
ug-0
8Se
p-08
Oct
-08
Nov
-08
Dec
-08
Jan-
09Fe
b-09
Mar
-09
Apr
-09
May
-09
Jun-
09Ju
l-09
Aug
-09
Sep-
09O
ct-0
9N
ov-0
9D
ec-0
9
Avai
labi
lity
(%)
0
2
4
6
8
10
12
14
16
Jul-0
4A
ug-0
4Se
p-04
Oct
-04
Nov
-04
Dec
-04
Jan-
05Fe
b-05
Mar
-05
Apr
-05
May
-05
Jun-
05Ju
l-05
Aug
-05
Sep-
05O
ct-0
5N
ov-0
5D
ec-0
5Ja
n-06
Feb-
06M
ar-0
6A
pr-0
6M
ay-0
6Ju
n-06
Jul-0
6A
ug-0
6Se
p-06
Oct
-06
Nov
-06
Dec
-06
Jan-
07Fe
b-07
Mar
-07
Apr
-07
May
-07
Jun-
07Ju
l-07
Aug
-07
Sep-
07O
ct-0
7N
ov-0
7D
ec-0
7Ja
n-08
Feb-
08M
ar-0
8A
pr-0
8M
ay-0
8Ju
n-08
Jul-0
8A
ug-0
8Se
p-08
Oct
-08
Nov
-08
Dec
-08
Jan-
09Fe
b-09
Mar
-09
Apr
-09
May
-09
Jun-
09Ju
l-09
Aug
-09
Sep-
09O
ct-0
9N
ov-0
9D
ec-0
9
Win
d Sp
eed
(m/s
)
02468
10121416
Jul-0
4A
ug-0
4Se
p-04
Oct
-04
Nov
-04
Dec
-04
Jan-
05Fe
b-05
Mar
-05
Apr
-05
May
-05
Jun-
05Ju
l-05
Aug
-05
Sep-
05O
ct-0
5N
ov-0
5D
ec-0
5Ja
n-06
Feb-
06M
ar-0
6A
pr-0
6M
ay-0
6Ju
n-06
Jul-0
6A
ug-0
6Se
p-06
Oct
-06
Nov
-06
Dec
-06
Jan-
07Fe
b-07
Mar
-07
Apr
-07
May
-07
Jun-
07Ju
l-07
Aug
-07
Sep-
07O
ct-0
7N
ov-0
7D
ec-0
7Ja
n-08
Feb-
08M
ar-0
8A
pr-0
8M
ay-0
8Ju
n-08
Jul-0
8A
ug-0
8Se
p-08
Oct
-08
Nov
-08
Dec
-08
Jan-
09Fe
b-09
Mar
-09
Apr
-09
May
-09
Jun-
09Ju
l-09
Aug
-09
Sep-
09O
ct-0
9N
ov-0
9D
ec-0
9
Win
d Sp
eed
(m/s
)
Scroby Sands (30 x V80-2MW - UK Offshore) North Hoyle (30 x V80-2MW - UK Offshore)
Kentish Flats (30 x V90-3MW - UK Offshore) Barrow (30 × V90-3MW - UK Offshore)
Egmond aan Zee (36 × V90-3MW - NL Offshore)
Capacity Factor
02468
10121416
Jul-0
4A
ug-0
4Se
p-04
Oct
-04
Nov
-04
Dec
-04
Jan-
05Fe
b-05
Mar
-05
Apr
-05
May
-05
Jun-
05Ju
l-05
Aug
-05
Sep-
05O
ct-0
5N
ov-0
5D
ec-0
5Ja
n-06
Feb-
06M
ar-0
6A
pr-0
6M
ay-0
6Ju
n-06
Jul-0
6A
ug-0
6Se
p-06
Oct
-06
Nov
-06
Dec
-06
Jan-
07Fe
b-07
Mar
-07
Apr
-07
May
-07
Jun-
07Ju
l-07
Aug
-07
Sep-
07O
ct-0
7N
ov-0
7D
ec-0
7Ja
n-08
Feb-
08M
ar-0
8A
pr-0
8M
ay-0
8Ju
n-08
Jul-0
8A
ug-0
8Se
p-08
Oct
-08
Nov
-08
Dec
-08
Jan-
09Fe
b-09
Mar
-09
Apr
-09
May
-09
Jun-
09Ju
l-09
Aug
-09
Sep-
09O
ct-0
9N
ov-0
9D
ec-0
9
Win
d Sp
eed
(m/s
)
Scroby Sands (30 x V80-2MW - UK Offshore) North Hoyle (30 x V80-2MW - UK Offshore)
Kentish Flats (30 x V90-3MW - UK Offshore) Barrow (30 × V90-3MW - UK Offshore)
Egmond aan Zee (36 × V90-3MW - NL Offshore)
0
10
20
30
40
50
60
70
80
90
100
Jul-0
4A
ug-0
4Se
p-04
Oct
-04
Nov
-04
Dec
-04
Jan-
05Fe
b-05
Mar
-05
Apr
-05
May
-05
Jun-
05Ju
l-05
Aug
-05
Sep-
05O
ct-0
5N
ov-0
5D
ec-0
5Ja
n-06
Feb-
06M
ar-0
6A
pr-0
6M
ay-0
6Ju
n-06
Jul-0
6A
ug-0
6Se
p-06
Oct
-06
Nov
-06
Dec
-06
Jan-
07Fe
b-07
Mar
-07
Apr
-07
May
-07
Jun-
07Ju
l-07
Aug
-07
Sep-
07O
ct-0
7N
ov-0
7D
ec-0
7Ja
n-08
Feb-
08M
ar-0
8A
pr-0
8M
ay-0
8Ju
n-08
Jul-0
8A
ug-0
8Se
p-08
Oct
-08
Nov
-08
Dec
-08
Jan-
09Fe
b-09
Mar
-09
Apr
-09
May
-09
Jun-
09Ju
l-09
Aug
-09
Sep-
09O
ct-0
9N
ov-0
9D
ec-0
9
Capa
city F
acto
r (%
)
0
10
20
30
40
50
60
70
80
90
100
Jul-0
4A
ug-0
4Se
p-04
Oct
-04
Nov
-04
Dec
-04
Jan-
05Fe
b-05
Mar
-05
Apr
-05
May
-05
Jun-
05Ju
l-05
Aug
-05
Sep-
05O
ct-0
5N
ov-0
5D
ec-0
5Ja
n-06
Feb-
06M
ar-0
6A
pr-0
6M
ay-0
6Ju
n-06
Jul-0
6A
ug-0
6Se
p-06
Oct
-06
Nov
-06
Dec
-06
Jan-
07Fe
b-07
Mar
-07
Apr
-07
May
-07
Jun-
07Ju
l-07
Aug
-07
Sep-
07O
ct-0
7N
ov-0
7D
ec-0
7Ja
n-08
Feb-
08M
ar-0
8A
pr-0
8M
ay-0
8Ju
n-08
Jul-0
8A
ug-0
8Se
p-08
Oct
-08
Nov
-08
Dec
-08
Jan-
09Fe
b-09
Mar
-09
Apr
-09
May
-09
Jun-
09Ju
l-09
Aug
-09
Sep-
09O
ct-0
9N
ov-0
9D
ec-0
9
Avai
labi
lity
(%)
0
2
4
6
8
10
12
14
16
Jul-0
4A
ug-0
4Se
p-04
Oct
-04
Nov
-04
Dec
-04
Jan-
05Fe
b-05
Mar
-05
Apr
-05
May
-05
Jun-
05Ju
l-05
Aug
-05
Sep-
05O
ct-0
5N
ov-0
5D
ec-0
5Ja
n-06
Feb-
06M
ar-0
6A
pr-0
6M
ay-0
6Ju
n-06
Jul-0
6A
ug-0
6Se
p-06
Oct
-06
Nov
-06
Dec
-06
Jan-
07Fe
b-07
Mar
-07
Apr
-07
May
-07
Jun-
07Ju
l-07
Aug
-07
Sep-
07O
ct-0
7N
ov-0
7D
ec-0
7Ja
n-08
Feb-
08M
ar-0
8A
pr-0
8M
ay-0
8Ju
n-08
Jul-0
8A
ug-0
8Se
p-08
Oct
-08
Nov
-08
Dec
-08
Jan-
09Fe
b-09
Mar
-09
Apr
-09
May
-09
Jun-
09Ju
l-09
Aug
-09
Sep-
09O
ct-0
9N
ov-0
9D
ec-0
9
Win
d Sp
eed
(m/s
)
Availability and Capacity Factor
• Capacity factor depends upon availability
• Large variations in availability
• What is causing availability to vary?– ‘Seasonal’ variations are not consistent– What about the wind conditions?
• What is the result?
Kentish Flats (V90)Scroby Sands (30 x V80)
Egmond aan Zee (36 x V90)North Hoyle (30 x V80)
0102030405060708090
100
0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0
Avai
labi
lity
(%)
Wind Speed (m/s)
Monthly Availability with Wind Speed
0102030405060708090
100
0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0
Avai
labi
lity
(%)
Wind Speed (m/s)
Monthly Availability with Wind Speed
0102030405060708090
100
0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0
Avai
labi
lity
(%)
Wind Speed (m/s)
Monthly Availability with Wind Speed
0102030405060708090
100
0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0
Avai
labi
lity
(%)
Wind Speed (m/s)
Monthly Availability with Wind Speed
Availability and Wind Speed
Energy and Wind SpeedKentish Flats (30 x V90-3MW)Scroby Sands (30 x V80-2MW)
Egmond aan Zee (36 x V90-3MW)North Hoyle (30 x V80-2MW)
0
500
1000
1500
2000
5 6 7 8 9 10 11 12 13
Ener
gy (M
Wh)
Scroby Sands: Energy Generated and Theoretically Lost due to Unavailability per Turbine over 3 years
Energy Generated Theoretical Lost Energy due to Unavailability
0
500
1000
1500
2000
5 6 7 8 9 10 11 12 13
Ener
gy (M
Wh)
Kentish Flats: Energy Generated and Theoretically Lost due to Unavailability per Turbine over 3 years
Energy Generated Theoretical Lost Energy due to Unavailability
0
500
1000
1500
2000
5 6 7 8 9 10 11 12 13
Ener
gy (M
Wh)
North Hoyle: Energy Generated and Theoretically Lost due to Unavailability per Turbine over 3 years
Energy Generated Theoretical Lost Energy due to Unavailability
0
500
1000
1500
2000
5 6 7 8 9 10 11 12 13
Ener
gy (M
Wh)
Egmond aan Zee: Energy Generated and Theoretically Lost due to Unavailability per Turbine over 3 years
Energy Generated Theoretical Lost Energy due to Unavailability
0
500
1000
1500
2000
5 6 7 8 9 10 11 12 13
Ener
gy (M
Wh)
Egmond aan Zee: Energy Generated and Theoretically Lost due to Unavailability per Turbine over 3 years
Energy Generated Theoretical Lost Energy due to Unavailability
Energy and Wind Speed
0%
20%
40%
60%
80%
100%
5 6 7 8 9 10 11 12 13
Ener
gy (M
Wh)
Egmond aan Zee: Energy Generated and Theoretically Lost due to Unavailability per Turbine over 3 years
Energy Generated Theoretical Lost Energy due to Unavailability
0%
20%
40%
60%
80%
100%
5 6 7 8 9 10 11 12 13
Ener
gy (M
Wh)
Scroby Sands: Energy Generated and Theoretically Lost due to Unavailability over 3 years
Energy Generated Theoretical Lost Energy due to Unavailability
0%
20%
40%
60%
80%
100%
5 6 7 8 9 10 11 12 13
Ener
gy (M
Wh)
Kentish Flats: Energy Generated and Theoretically Lost due to Unavailability over 3 years
Series1 Series2
0%
20%
40%
60%
80%
100%
5 6 7 8 9 10 11 12 13
Ener
gy (M
Wh)
North Hoyle: Energy Generated and Theoretically Lost due to Unavailability over 3 years
Energy Generated Theoretical Lost Energy due to Unavailability
0
500
1000
1500
2000
5 6 7 8 9 10 11 12 13
Ener
gy (M
Wh)
Egmond aan Zee: Energy Generated and Theoretically Lost due to Unavailability per Turbine over 3 years
Energy Generated Theoretical Lost Energy due to Unavailability
Kentish Flats (30 x V90-3MW)Scroby Sands (30 x V80-2MW)
Egmond aan Zee (36 x V90-3MW)North Hoyle (30 x V80-2MW)
0%
20%
40%
60%
80%
100%
5 6 7 8 9 10 11 12 13
Ener
gy (%
)
Kentish Flats: Energy Generated and Theoretically Lost due to Unavailability over 3 years
Series1 Series2
0%
20%
40%
60%
80%
100%
5 6 7 8 9 10 11 12 13
Ener
gy (%
)
Kentish Flats: Energy Generated and Theoretically Lost due to Unavailability over 3 years
Series1 Series2
0%
20%
40%
60%
80%
100%
5 6 7 8 9 10 11 12 13
Ener
gy (%
)
Kentish Flats: Energy Generated and Theoretically Lost due to Unavailability over 3 years
Series1 Series2
0%
20%
40%
60%
80%
100%
5 6 7 8 9 10 11 12 13
Ener
gy (%
)
Kentish Flats: Energy Generated and Theoretically Lost due to Unavailability over 3 years
Series1 Series2
0
5
10
15
20
25
30
0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0
Unw
orka
ble
Day
s
Wind Speed (m/s)
Monthly Unworkable Days with Wind Speed
0
5
10
15
20
25
30
0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0
Unw
orka
ble
Day
s
Wind Speed (m/s)
Monthly Unworkable Days with Wind Speed
0
5
10
15
20
25
30
0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0
Unw
orka
ble
Day
s
Wind Speed (m/s)
Monthly Unworkable Days with Wind Speed
Kentish Flats (30 x V90-3MW)Scroby Sands (30 x V80-2MW)
Egmond aan Zee (36 x V90-3MW)
Unworkable Days
Kentish Flats (30 x V90-3MW)Scroby Sands (30 x V80-2MW)
Egmond aan Zee (36 x V90-3MW)
0
20
40
60
80
100
0.0 5.0 10.0 15.0 20.0 25.0 30.0
Avai
labi
lity
(%)
Unworkable Days
Monthly Availability with Unworkable Days
0
20
40
60
80
100
0.0 5.0 10.0 15.0 20.0 25.0 30.0
Avai
labi
lity
(%)
Unworkable Days
Monthly Availability with Unworkable Days
0
20
40
60
80
100
0.0 5.0 10.0 15.0 20.0 25.0 30.0
Avai
labi
lity
(%)
Unworkable Days
Monthly Availability with Unworkable Days
Availability and Unworkable Days
Kentish Flats (30 x V90-3MW)Scroby Sands (30 x V80-2MW)
Egmond aan Zee (36 x V90-3MW)
0
20
40
60
80
100
0.0 5.0 10.0 15.0 20.0 25.0 30.0
Avai
labi
lity
(%)
Unworkable Days
Monthly Availability with Unworkable Days
0
20
40
60
80
100
0.0 5.0 10.0 15.0 20.0 25.0 30.0
Avai
labi
lity
(%)
Unworkable Days
Monthly Availability with Unworkable Days
0
20
40
60
80
100
0.0 5.0 10.0 15.0 20.0 25.0 30.0
Avai
labi
lity
(%)
Unworkable Days
Monthly Availability with Unworkable Days
Availability and Unworkable Days
No relationshipWater depth = 3.6m
Kentish Flats (30 x V90-3MW)Scroby Sands (30 x V80-2MW)
Egmond aan Zee (36 x V90-3MW)
0
20
40
60
80
100
0.0 5.0 10.0 15.0 20.0 25.0 30.0
Avai
labi
lity
(%)
Unworkable Days
Monthly Availability with Unworkable Days
0
20
40
60
80
100
0.0 5.0 10.0 15.0 20.0 25.0 30.0
Avai
labi
lity
(%)
Unworkable Days
Monthly Availability with Unworkable Days
0
20
40
60
80
100
0.0 5.0 10.0 15.0 20.0 25.0 30.0
Avai
labi
lity
(%)
Unworkable Days
Monthly Availability with Unworkable Days
Availability and Unworkable Days
No relationshipWater depth = 3.6m
Decreasing availabilityWater depth = 9.8m
Kentish Flats (30 x V90-3MW)Scroby Sands (30 x V80-2MW)
Egmond aan Zee (36 x V90-3MW)
0
20
40
60
80
100
0.0 5.0 10.0 15.0 20.0 25.0 30.0
Avai
labi
lity
(%)
Unworkable Days
Monthly Availability with Unworkable Days
0
20
40
60
80
100
0.0 5.0 10.0 15.0 20.0 25.0 30.0
Avai
labi
lity
(%)
Unworkable Days
Monthly Availability with Unworkable Days
0
20
40
60
80
100
0.0 5.0 10.0 15.0 20.0 25.0 30.0
Avai
labi
lity
(%)
Unworkable Days
Monthly Availability with Unworkable Days
Availability and Unworkable Days
No relationshipWater depth = 3.6m
Significantly decreasing availabilityWater depth = 12.8m
Decreasing availabilityWater depth = 9.8m
Conclusions
• Offshore wind is achieving higher capacity factors than onshore– Highly variable availability– Season and wind speed dependent
• Large energy losses at certain wind speeds– Wind speed, water depth and unworkable days are linked
• Stops must be occurring at higher wind speeds– A reliability problem
• Unable to access turbines for repair– An operations problem
Why Worry?
Location Water Depth
(m) Distance to Shore (km)
Reported Wind Farms
North Hoyle, UK 7-11 6
Scroby Sands, UK 5-10 2.3
Kentish Flats, UK 5 8.5
Barrow, UK 15-20 7.5
Egmond aan Zee, NL 19-22 10
Why Worry?
Location Water Depth
(m)
Distance to Shore (km)
Reported Wind Farms
North Hoyle, UK 7-11 6
Scroby Sands, UK 5-10 2.3
Kentish Flats, UK 5 8.5
Barrow, UK 15-20 7.5
Egmond aan Zee, NL 19-22 10
UK Round 3
Firth of Forth 31-62 37-77
Dogger Bank 18-63 125-290
Irish Sea 26-74 15-40
Operational and Reliability Analysis of Offshore Wind Farms
Thank you for listening
Dr Christopher J. Crabtree