QSE Managers Working GroupNovember 7th 2011

NPRR 334 – Additional Analysis

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Background

• NPRR limits the amount of Regulation from a single Resource to be less than or equal to X% of system wide Regulation requirement.

• When a limited number of Resources are providing Regulation Service, ERCOT is vulnerable to unavailability of the service in Real Time due to – Failure to provide due to Resource failure– Failure to provide due to Resource being moved up to lower ramp rate

region– Un-deliverability due to transmission constraint

• Mostly these type of issues happen during Operating period when SASM cannot be opened to cover the unavailable AS

• The NPRR increases the distribution of Regulation Service responsibilities and hence reduces reliability risks

• Reduces the need for committing Resource in RUC for AS and reduces the number of SASMs

• Reduces the need for manual intervention by operator to enter offset to recover frequency if units providing regulation are not responding to regulation deployment.

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August 11 PDCWG Comments

The PDCWG believes that the initial value of X% should be set at 30%. This is based on the average Primary Frequency Response of the ERCOT System that since Dec 1, 2010 is approximately -490 MW/0.1 Hz. The momentary loss of 30% of Regulation Service from a single Resource would impact ERCOT System frequency approximately +/-0.0613 Hz which is well within the frequency trigger limit of the BAAL field trial. With SCED’s ability to recover Regulation Service every five minutes, the loss of Regulation Service will be minimized. The 30% limit will require a minimum of four Resources to provide the service.

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Resources carrying >= 30% Reg requirement

This shows information about 5 min intervals in which at least one resource is providing more than 30% regulation requirement

 

# intervals w/Resource RegUp >=30%

# intervals w/Resource RegDn >=30%

# intervals in month

Percent of SCED Executions At Least One Resource Had 30% or More of the Reg. Up

Percent of SCED Executions At Least One Resource Had 30% or More of the Reg. Down

# of hrs regup

Dec 1425 7 10593 13.45% 0.07% 119Jan 3006 16 9220 32.60% 0.17% 251Feb 4459 14 8282 53.84% 0.17% 372Mar 2147 145 9159 23.44% 1.58% 179Apr 1195 569 8917 13.40% 6.38% 100May 1250 147 9131 13.69% 1.61% 104Jun 384 1024 8879 4.32% 11.53% 32Jul 949 544 9023 10.52% 6.03% 79Aug 856 633 8992 9.52% 7.04% 71Sep 1560 15 8805 17.72% 0.17% 130

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Resources carrying >= 40% Reg requirement

This shows information about intervals in which at least one resource is providing more than 40% regulation requirement

 

# intervals w/Resource RegUp >=40%

# intervals w/Resource RegDn >=40%

# intervals in month

Percent of SCED Executions At Least One Resource Had 40% or More of the Reg. Up

Percent of SCED Executions At Least One Resource Had 40% or More of the Reg. Down

# of hrs regup

Dec 531 0 10593 5.01% 0.00% 44Jan 393 0 9220 4.26% 0.00% 33Feb 1095 1 8282 13.22% 0.01% 91Mar 284 5 9159 3.10% 0.05% 24Apr 35 178 8917 0.39% 2.00% 3May 0 0 9131 0.00% 0.00% 0Jun 0 8 8879 0.00% 0.09% 0Jul 0 4 9023 0.00% 0.04% 0Aug 85 4 8992 0.95% 0.04% 7Sep 141 0 8805 1.60% 0.00% 12

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Resources carrying >= 50% Reg requirement

This shows information about intervals in which at least one resource is providing more than 50% regulation requirement

 

# intervals w/Resource RegUp >=50%

# intervals w/Resource RegDn >=50%

# intervals in month

Percent of SCED Executions At Least One Resource Had 50% or More of the Reg. Up

Percent of SCED Executions At Least One Resource Had 50% or More of the Reg. Down

# of hrs regup

Dec 212 0 10593 2.00% 0.00% 18Jan 12 0 9220 0.13% 0.00% 1Feb 29 1 8282 0.35% 0.01% 2Mar 6 5 9159 0.07% 0.05% 1Apr 20 0 8917 0.22% 0.00% 2May 0 0 9131 0.00% 0.00% 0Jun 0 2 8879 0.00% 0.02% 0Jul 0 1 9023 0.00% 0.01% 0Aug 1 1 8992 0.01% 0.01% 0Sep 0 0 8805 0.00% 0.00% 0

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Undeliverable in the operaing hour

Percent of 5 minute intervals in a month when transmission constraint was affecting # of resources carrying Reg-Up

Month-Year

AVG Number of Resources carrying Reg-Up

Max Number of Resources carrying Reg-Up

Min Number of Resources carrying Reg-Up

0-5 Resources

5-15 Resources

15-25 Resources

Greater than 25 Resources

sum

Dec-10 31 44 (1.20% intervals >35)

13 (0.067%<20)

27.09% 12.47% 6.35% 0.16% 46.07%

Jan-11 14 39(0.44% intervals >30)

8 (5.11%<20) 7.76% 12.70% 3.99% 0.62% 25.07%

Feb-11 17 41 (2.43% intervals >30)

6 (9.62%<10) 13.99% 15.35% 7.97% 1.62% 38.93%

Mar-11 17 29 (2.14% intervals > 25)

6 (6.18% < 10) 7.27% 6.90% 7.21% 0.02% 21.40%

Apr-11 19 41 (1.67% intervals > 30)

9 (20.60% < 15)

19.15% 15.03% 6.14% 0.23% 40.55%

May-11 21 39 (16.08% intervals > 25)

10 (10.41% < 15)

25.58% 20.48% 11.74% 0.90% 58.70%

Looking at resources carrying reg that are constrained  (LMP< System lambda)  1% ~= ninty 5-minute intervals or 7.5 hrs 

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NPRR 334 – Additional Analysis

• Evaluated based on amount of MWs on a single resource versus percentage of requirement

• Evaluated based on number of resources carrying this amount

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NPRR 334 – Additional Analysis

• Intervals with a single Resource carrying >= 50 MW

 

# intervals w/Resource

RegUp >=50MW

# intervals w/Resource

RegDn >=50MW

# intervals in month

Percent of SCED Executions At Least One Resource Had 50MW or

More of the Reg. Up

Percent of SCED Executions At Least One Resource Had 50MW or More of the Reg. Down

Dec 10518 10490 10593 99.29% 99.03%

Jan 9220 9063 9220 100.00% 98.30%

Feb 8282 8130 8282 100.00% 98.16%

Mar 9159 8588 9159 100.00% 93.77%

Apr 8894 8794 8917 99.74% 98.62%

May 9131 8289 9131 100.00% 90.78%

Jun 8879 8398 8879 100.00% 94.58%

Jul 8964 8765 9023 99.35% 97.14%

Aug 8992 8415 8992 100.00% 93.58%

Sep 8805 8521 8805 100.00% 96.77%

Total 90844 87453 91001 99.83% 96.10%

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NPRR 334 – Additional Analysis

• Intervals with a single Resource carrying >= 100 MW

 

# intervals w/Resource

RegUp >=100MW

# intervals w/Resource

RegDn >=100MW

# intervals in month

Percent of SCED Executions At Least One Resource Had

100MW or More of the Reg. Up

Percent of SCED Executions At Least One Resource Had

100MW or More of the Reg. Down

Dec 2963 811 10593 27.97% 7.66%

Jan 8482 180 9220 92.00% 1.95%

Feb 7988 906 8282 96.45% 10.94%

Mar 9131 1436 9159 99.69% 15.68%

Apr 8278 1278 8917 92.83% 14.33%

May 8990 716 9131 98.46% 7.84%

Jun 7966 3413 8879 89.72% 38.44%

Jul 7456 3500 9023 82.63% 38.79%

Aug 6300 2011 8992 70.06% 22.36%

Sep 6634 702 8805 75.34% 7.97%

Total 74188 14953 91001 81.52% 16.43%

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NPRR 334 – Additional Analysis

• Intervals with a single Resource carrying >= 150 MW

 

# intervals w/Resource

RegUp >=150MW

# intervals w/Resource

RegDn >=150MW

# intervals in month

Percent of SCED Executions At Least One Resource Had 150MW or More of

the Reg. Up

Percent of SCED Executions At Least One Resource Had

150MW or More of the Reg. Down

Dec 814 0 10593 7.68% 0.00%

Jan 1220 12 9220 13.23% 0.13%

Feb 2576 25 8282 31.10% 0.30%

Mar 2709 17 9159 29.58% 0.19%

Apr 2101 14 8917 23.56% 0.16%

May 4499 0 9131 49.27% 0.00%

Jun 367 0 8879 4.13% 0.00%

Jul 97 144 9023 1.08% 1.60%

Aug 267 1 8992 2.97% 0.01%

Sep 147 0 8805 1.67% 0.00%Total 14797 213 91001 16.26% 0.23%

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NPRR 334 – Additional Analysis

• Intervals with a single Resource carrying >= 200 MW

 

# intervals w/Resource

RegUp >=200MW

# intervals w/Resource

RegDn >=200MW

# intervals in month

Percent of SCED Executions At Least One Resource Had

200MW or More of the Reg. Up

Percent of SCED Executions At Least One Resource Had 200MW or More of the Reg. Down

Dec 147 0 10593 1.39% 0.00%

Jan 49 0 9220 0.53% 0.00%

Feb 1 1 8282 0.01% 0.01%

Mar 5 5 9159 0.05% 0.05%

Apr 0 0 8917 0.00% 0.00%

May 5 0 9131 0.05% 0.00%

Jun 13 0 8879 0.15% 0.00%

Jul 0 0 9023 0.00% 0.00%

Aug 1 1 8992 0.01% 0.01%

Sep 0 0 8805 0.00% 0.00%

Total 221 7 91001 0.24% 0.01%

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NPRR 334 – Additional Analysis

• Intervals with a single Resource carrying >= 250 MW

 

# intervals w/Resource

RegUp >=250MW

# intervals w/Resource

RegDn >=250MW

# intervals in month

Percent of SCED Executions At Least One Resource Had

250MW or More of the Reg. Up

Percent of SCED Executions At Least One Resource Had 250MW or More of the Reg. Down

Dec 121 0 10593 1.14% 0.00%

Jan 0 0 9220 0.00% 0.00%

Feb 1 1 8282 0.01% 0.01%

Mar 5 5 9159 0.05% 0.05%

Apr 0 0 8917 0.00% 0.00%

May 0 0 9131 0.00% 0.00%

Jun 13 0 8879 0.15% 0.00%

Jul 0 0 9023 0.00% 0.00%

Aug 1 1 8992 0.01% 0.01%

Sep 0 0 8805 0.00% 0.00%

Total 141 7 91001 0.15% 0.01%

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NPRR 334 – Additional Analysis

# of Resources

with >=50MW of

Regup

with >=100M

W of Regup

with >=150MW of Regup

with >=50MW of Regdn

with >=100MW of Regdn

with >=150MW of Regdn

1 4986 48442 14042 15774 14526 212

2 15634 19312 719 21791 419 1

3 20147 5950 36 22422 7  

4 23718 484   16286 1  

5 14984     7765    

6 6953     2506    

7 2698     671    

8 1192     192    

9 456     28    

10 67     18    

11 9          

Total 90844 74188 14797 87453 14953 213

• Intervals where X Resources carried above X MWs (December – September)