Review of SONI Power System

Operations

Alex Baird

Grid Operations Manager

Real Time

Presentation Structure

• System statistics– NI Summary– NI fuel mix– Gas as a percentage of System demand– Wind Statistics– Wind as a percentage of system demand

• System operation issues– Moyle flow– Moyle flows too low– Moyle flows too high– Moyle flows in future

• Winter Outlook for 2009/10

System Statistics

NI Summary System Statistics

• Main thermal Generating Plant 1996 MW with 291 MW of OCGTs giving a total (sent out) figure of 2287MW

• Generating stations 3

– Moyle DC interconnector to GB -80/450MW

– Energy 2009 YTD 5.85 TWh

• Energy Growth (year on year) for Sept -2.67%

• MW Load variation from 516 to 1725

Current NI Fuel Mix (Oct 2009)

Gas66%

Coal21%

Wind13%

Gas % System DemandJan – Aug 2009

0

20

40

60

80

100

120

140

Date

Perc

enta

ge *

* Note that % Gas can exceed NI demand during periods where exporting to ROI

Wind Statistics

• Wind Generation capacity 292 MW

• No. of Wind farms 21

• Expected Capacity by end 2009 (extension to existing site) 303 MW

• Peak wind output (3rd Oct 09 01:00) 273 MW

• Wind contribution at system peak (29 Jan 09 @ 17:30) 195MW

• No transmission connected wind farms

Wind % of System DemandJan – Aug 2009

26 July 2009 05:00

0

5

10

15

20

25

30

35

40

45

01/0

1/20

09

08/0

1/20

09

15/0

1/20

09

22/0

1/20

09

29/0

1/20

09

05/0

2/20

09

12/0

2/20

09

19/0

2/20

09

26/0

2/20

09

05/0

3/20

09

12/0

3/20

09

19/0

3/20

09

26/0

3/20

09

02/0

4/20

09

09/0

4/20

09

16/0

4/20

09

23/0

4/20

09

30/0

4/20

09

07/0

5/20

09

14/0

5/20

09

21/0

5/20

09

28/0

5/20

09

04/0

6/20

09

11/0

6/20

09

18/0

6/20

09

25/0

6/20

09

02/0

7/20

09

09/0

7/20

09

16/0

7/20

09

23/0

7/20

09

30/0

7/20

09

06/0

8/20

09

13/0

8/20

09

20/0

8/20

09

27/0

8/20

09

Date

Per

cent

age

System Operation Issues

Moyle Flow

• Flow on the Moyle interconnector is decided as the result of the ex-ante UUC run

• The UUC takes no account of system constraints

• The TSO can only alter this flow by SO-SO trading with NGC

• SO-SO trading is agreed close to real time and is only firm once agreed

Moyle and the System – 16th Nov 2008

• Four large units unavailable in NI giving a thermal cover figure of only 858MW

• South - North tie line had a 380MW Total Transfer Capacity (TTC) giving maximum contribution circa 220MW

• Moyle at peak only 50MW but for long periods was exporting 50MW

• Wind forecast 0 MW

• Load forecast at peak 1458MW

• Result of the above is a very concerned system operator

Moyle and the System – 16th Nov 2008

0

200

400

600

800

1000

1200

1400

1600

0

200

400

600

800

1000

1200

1400

1600

NI Generation

NI Demand

Wind

S-N Support

Moyle Schedule Flow

Short Fall

Moyle and the System – 16th Nov 2008

-100

0

100

200

300

400

500

600

Moyle Actual Flow

Moyle Market Scheduled Flow

Moyle and the System – 8th Sep 2009

• Moyle scheduled import was 305 MW from 01:00 to 05:00

• North – South tie line had a 320MW TTC providing an export circa 200MW

• Wind generation approx. 240 MW all night

• NI minimum forecast demand was 610 MW over this period

• Three units required in NI at all times and on running plant this meant a min gen level of 430MW

Moyle and the System – 8th Sep 2009

0

200

400

600

800

1000

1200

1400

1600

NI Generation (inc. Moyle)

0

200

400

600

800

1000

1200

1400

1600

0

200

400

600

800

1,000

1,200

1,400

1,600

NI Demand

N-S Flow

NI Over Generation

Moyle and the System – 8th Sep 2009

0

50

100

150

200

250

300

350

400

450

Actual Moyle

Scheduled Moyle

Moyle flows in future

• The foregoing slides demonstrate the need for a mechanism to alter Moyle flows firmly and ahead of real time

• The SOs have been engaging with the Regulatory Authorities on mechanisms which can achieve this end

• From this engagement the SOs were directed to put in place a contract with NGC that allowed day ahead SO-SO trading on a firm basis

• This work is currently in progress

Winter Outlook

Winter Outlook 2009/10

• Estimate 1589 MW (highly temperature dependent)

• Decrease of 136 MW from 2008/9

• Two additional Open Cycle Gas turbines from last winter (84 MW)

• Additional 100 MW of wind expected compared to last winter

• Firm day ahead trading expected with NGC before the end of 09

Review of SONI Power System

Operations

Alex Baird

Grid Operations Manager

Real Time