January, 30 2013 | holyokE , ma

1. January, 30 2013 | holyokE, ma Resource analysis and qualification Demand Resource Working Group Market Resource Alternative Analysis – Demand-side Results Greater Hartford and Central Connecticut Area

2. Background • Planning Advisory Committee (PAC) stakeholders suggested providing additional information on Market Resource Alternatives (MRAs) as a supplement to the Transmission System Needs Assessments and other information presented in the regional planning process • MRAs may be alternatives to regulated transmission solutions and may include demand-side and supply-side resources • On May 26, 2011, ISO-NE presented results associated with the New Hampshire/Vermont (NH/VT) Pilot Study https://smd.iso-ne.com/committees/comm_wkgrps/prtcpnts_comm/pac/ceii/mtrls/2011/may262011/nta_analysis.pdf • On November 14, 2012, ISO-NE presented demand-side results related to the 2012 MRA analysis for the Greater Hartford and Central Connecticut (GHCC) area https://smd.iso-ne.com/committees/comm_wkgrps/prtcpnts_comm/pac/ceii/mtrls/2012/nov142012/ghcc_mra_november.pdf • On December 13, 2012, ISO-NE presented supply-side results related to the 2012 MRA analysis for the Greater Hartford and Central Connecticut (GHCC) area https://smd.iso-ne.com/committees/comm_wkgrps/prtcpnts_comm/pac/ceii/mtrls/2012/dec132012/ghcc_mra.pdf *Some of these reports may require CEII authorization to view. Refer to ISO-NE website for additional information

3. The Greater Hartford and Central Connecticut MRA Study • The MRA study is based on the Greater Hartford and Central Connecticut (GHCC) Transmission Needs Assessment https://smd.iso-ne.com/committees/comm_wkgrps/prtcpnts_comm/pac/ceii/mtrls/2012/aug92012/ghcc_needs.pdf • The goal of today’s discussion is to review the assumptions, methodology and results associated with demand-side MRAs for the Greater Hartford and Central Connecticut area • The Greater Hartford and Central Connecticut area includes four sub-areas: • Manchester/Barbour Hill • Middletown • Greater Hartford • Northwestern Connecticut

4. The Greater Hartford and Central Connecticut MRA Study, cont.

5. The Greater Hartford and Central Connecticut MRA Study, cont. • MRA study used the same conditions and study criteria used in the GHCC Transmission System Needs Assessment: • Load Levels: 2022 90/10 Summer Peak Load Level (Extrapolated from CELT 2012) • NE load level: 34,1301 MW • CT (RSP2): 8,7651 MW • Includes of the 100% of the Passive and 75% of the Active Demand Response (DR) cleared in FCA (#1 - #6) • Passive demand resources were modeled via a load reduction spread across their respective Load Zones • Active demand resources were modeled via a load reduction spread across their respective Dispatch Zones • Includes 100% of the Energy Efficiency (EE) forecast for the remaining years 2016 through 20213 http://www.iso-ne.com/committees/comm_wkgrps/prtcpnts_comm/pac/mtrls/2012/apr182012/final_ee_forecast.pdf • Considered all N-1 and N-1-1 scenarios used in the transmission assessment • Focused on physical system needs • All loadings brought at or below 100% of the relevant transmission element rating • Normal rating for all-lines-in conditions • Long Time Emergency (LTE) rating following single or multi-element outages 1 – Includes T&D losses 2 – Excludes parts of CT Load that is fed from Western Massachusetts 3 – The EE forecast was extrapolated for year 2022

6. Demand-side MRA Analysis – Approach, cont. • The net load at each load-serving bus is determined by taking into account the amount of load remaining to be served after all active and passive (including EE) demand resource measures have been modeled at that bus • As an illustration, on the bus diagram shown below, the following load and demand resource measures are modeled: L = Total Bus Load = 24.3 MW A = Active DR = - 0.5 MW P = Passive DR = - 1.0 MW Note that the DR measures are modeled as negative loads • The amount of net load (in MW) to be served at the bus is 22.8 MW Net load at the bus = total bus load + active DR + passive DR = 24.3 MW – 0.5 MW – 1.0 MW = 22.8 MW • A security constrained dispatch algorithm is used to determine the minimum amount and best location of the load reduction needed at each load-serving bus to relieve all overloads for each system condition under consideration • For each load-serving bus the amount of load reduction available to the software is limited to 100% of the amount of net load at the bus (22.8 MW in the example above) Bus L Loads

7. Illustration: Demand-side MRA Analysis Dispatch Zone 2 D Gen G1 Transmission System Needs Assessment: Under a scenario considering both the outages of Generator G2 and Line [BC], Line [AB] would be overloaded. Gen G2 B A Net Load Generator C Dispatch Zone 1 GenG3

8. Illustration: Demand-side MRA Analysis, cont. Dispatch Zone 2 MRA Demand-side resources: Demand-side resources are considered to relieve the Line [AB] overload. Demand-side resources are modeled by potential targeted load reduction at L1, L2, L3, L4 or L5. Software simulations show that load reduction at L3 and L4 by a certain percentage of the net bus load would reduce the loading on line [AB] to 100% of its rating. Load reduction at L1, L2 or L5 would be ineffective at relieving the line [AB] overload. Gen G1 L 3 D 100% Gen G2 B A L 4 C L 1 L 2 Dispatch Zone 1 GenG3 L 5

9. Demand-side MRA Analysis – Results • The analysis showed that a minimum of approximately 1,350 MW of available load reduction is required to resolve all N-1 and N-1-1 thermal issues in the study sub-areas • Each sub-area’s potential MRA does not work independently to satisfy the reliability need. All sub-areas’ MRAs together satisfy the reliability need as a unified solution • The next table shows the list of load-serving busses where reduction is needed, the size of the needed reduction and the frequency of exposure to a need for reduction at each load-serving bus *Sub-area Load= Remaining load after forecasted Energy Efficiency and cleared Demand Response reductions from FCA #1 – FCA #6 have been accounted for

10. Demand-side MRA Analysis – Results, cont. Barbour Hill sub-area Middletown sub-area Greater Hartford sub-area Northwestern CT sub-area

11. Conclusions • To be prepared to resolve all N-1 and N-1-1 thermal issues in the study sub-areas, the analysis shows that a minimum of approximately 1,350 MW of available load reduction is required • Highest % load reduction are often driven by specific line-out conditions • Highest frequency of need are observed at East New Britain, Newington, Northwest Hartford • High needs in the Northwestern Connecticut sub-area, as shown on slide 11 are driven by the assumption that the 690 Special Protection System is inactive; assuming that the 690 Special Protection System is active, the need becomes 131 MW • More details regarding the GHCC MRA analysis are available in the November and December PAC presentations https://smd.iso-ne.com/committees/comm_wkgrps/prtcpnts_comm/pac/ceii/mtrls/2012/nov142012/ghcc_mra_november.pdf https://smd.iso-ne.com/committees/comm_wkgrps/prtcpnts_comm/pac/ceii/mtrls/2012/dec132012/ghcc_mra.pdf

12. Additional Information • More information regarding the amount of load reduction that would be needed to resolve all needs can be determined from the Critical Load Level Analysis portion of the GHCC Transmission System Needs Assessment https://smd.iso-ne.com/committees/comm_wkgrps/prtcpnts_comm/pac/ceii/mtrls/2013/jan162013/a8_ghcc_needs_assessment_ii_011613.pdf • In this analysis, load was reduced uniformly across Connecticut to relieve all N-1 and N-1-1 thermal issues in the study sub-areas • Using slide 8’s illustration, this is equivalent to simultaneously reducing load at L1, L2, L3, L4 and L5 • This analysis suggests that the load in Connecticut would have to be reduced by 3,562 MW for all N-1 and N-1-1 thermal issues to be relieved • No new MRA analyses are expected to be performed in 2013