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Local Area Planning Update to TRANSAC – March 11, 2015

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Decision Rule - Matrix

Decision Rule Matrix - Example

Problem:Mitigation:

Raw RankUnits Data Factor Comment

Consequences of Event

MW Affected

Load Note 1 Describe load lost, voltage or thermal problems, etc

Risk of Event NoneDescribe problem

conditionsNote 2

Describe under what conditions the problem occurs: normal, outage, load level, seasons affected, etc

Overall Risk None Conseq X Risk = Result

CostTPV Rev

Req$ Cost -- List major cost components

Solution Duration Years Years -- Cost/Duration = $/year

Discussion

Note 1: Calculate and enter consequences factor per details on priority matrix

Note 2: Calculate and enter risk factor per details on priority matrix

Idenify the Problem or eventBriefly describe the mitigation proposed

Any other notes or comments on problem or proposed mitigation.

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Decision Rule - Example

Decision Rule Matrix

Problem:Mitigation:

Raw RankUnits Data Factor Comment

Consequence of event

MW Affected

53 105No risk of lost load, but voltages below FERC 715 minimums under normal system conditions, peak load.

RiskProb, Freq of event

Occurs now under normal and outage

conditions at peak loads0.25

Because problem occurs now under normal system conditions, but only at peak load, risk factor is 25%.

Con. X Risk None 105 X .25 26.3

CostTPV Rev

Req$2.1M --

50 MVAR E Helena, 25 MVAR Three Rivers, 10 MVAR at Broadwater @ $25K/MVAR

Solution Duration Years 15+ -- Cost/Duration = 2.1/15 = $0.14M/year

Discussion

Low Voltage Helena - Three Rivers Area 100 kV SystemOption A: Cap Banks at E Helena, Three Rivers, Broadwater

Installation of these cap banks provide a valid solution through 2023. E Helena and Three Rivers subs well developed and should accommodate cap banks, but new sub may be required at Broadwater or close vicinity. Solution could be staged in over time.

Prioritizing Critical Problems

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Consequences Factor = (Stability + Thermal + Voltage Problems Factors) X Peak Load Affected

Consequences Rating Factors

Stability and Thermal Problems Voltage Problems

Extreme – Interconnection wide Impacts, Widespread Outages 10 Outage 10

Severe – Division Wide Impacts, multiple outages 5 Very Low < 80% 5

Moderate – Localized Impacts, single outages 2 Low < FERC 715 2

Minor – Small Impacts, no outages 1 High 2

None – No problems observed 0 None 0 

Consequence Factors

Risk & Likelihood Factors

Prioritizing Critical Problems

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Risk Factor = System Cond. Factor X Seasonal Cond. Factor X Other Cond. Factor

Likelihood Factors

System ConditionSeasonal Condition Other Conditions

Normal .09995 S Peak 0.125 Normal – Occurs at N-0 Cond. 1.0

Outage 1 0.0005 W Peak 0.125 Major – Long line > 30 miles 1.0

Outage 2 0.00005 SW Peak 0.25 Moderate – Medium Line 0.5

    Light 0.25 Minor – Short Line < 3 miles 0.1

    Average 0.75 Sub – Substation Equipment 0.033

    All 1

Expected Consequences

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Expected Consequences

Expected Consequences = Consequences Factor X Risk Factor

Expected Consequences are used to rank and prioritize problems found. Additional factors may be used to weight the expected consequences, taking into account:

• Timing of a problem (far into the future could be ranked lower)• Different Contingencies that create the same problem (a

problem that could occur due to two different outages can be ranked higher).

• Additional Seasonal variations or other factors.

Suggestions:

• High Wind System Wide– Existing Projects dispatched to capacity

• Loss of Thermal Plants– Heavy Imports, Heavy Summer

• Loss of Hydros– Extreme Winter Conditions

• Extreme Localized Growth• Other?

Uncertainty Scenarios

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Uncertainty Scenarios

Quarters 6 & 7• Finalize Mitigation Plans under review or in progress• Run Uncertainty Scenarios• Perform Reactive Resource Assessment

Quarter 8• Send out Draft of “The Book” for stakeholder review• Conduct Public Meetings• Finalize “The Book” and close out the 2014/2015 Local Area

Planning Cycle

Next Steps

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Questions?

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