1 1 1 Central Maine Power Company Local System Plan Presentation Planning Advisory Committee Meeting October 21, 2010

2 2 2 Purpose of Local System Plan Per Attachment K – Local, this LSP presentation: Describes projected improvements to non-PTF that are needed to maintain reliable customer service. Reflects: –LSP Needs Assessments –Corresponding transmission system planning studies

3 3 3 LSP Communication LSP is communicated to the PAC at an ISO-NE PAC RSP meeting once a year. –Separate meetings can be arranged if needed PAC, Transmission Customers, and other Stakeholders have 30 days to provide written comments for consideration to CMP –CMP’s contact: Curtis Beveridge Manager System Planning Central Maine Power Company 83 Edison Drive Augusta, Maine (

4 4 4 LSP Communication cont. Each PTO is individually responsible for publicly posting and updating the status of its respective LSP and the transmission projects list on a website in a format similar to the RSP project list The ISO-NE RSP project list contains links to each individual PTO’s transmission project list CMP’s LSP project list is located at: Services/CMPTransmissionSvc/lsp.html

5 5 5 CMP LSP Project List Central Maine Power will update the LSP project list at least annually. A presentation of the LSP will be made annually. LSP Project List is a cumulative listing of proposed transmission solutions intended to meet identified needs. Similar to PTF projects in the RSP, the LSP project list contains a status of each non-PTF project: Concept-Project is under consideration as a possible solution to a need, but little or no analysis is available Proposed-CMP has determined that the project is an appropriate solution to a need, but has not yet obtained internal budget approval Planned-Budgetary approval has been obtained Under Construction- Project is approved and is under design/construction In-Service-Project is complete

6 6 6 CMP’s Local System Planning Process All CMP system upgrades are determined in accordance with Central Maine Power Company Transmission Planning Criteria. Planning studies can result from: –Periodic Assessment of CMP’s 14 Local Planning Areas –Load Growth –Retail or Wholesale Customer Request –Generator Interconnection Request –System-Wide Contingency Analysis Studies may utilize both ISO-NE Library Base Cases and/or Local CMP Base Cases. Generator Interconnections on the non-PTF Transmission System are guided by the CMP Transmission & Distribution Interconnection Requirements for Generation.

7 7 7 LSP Projects Need Projected In-Service Date Major Project Status Needs AssessmentSolutions Load Growth/ Sub-Area Study 2011 Portland North Area Reliability Study Line workProposed Could overload under normal operating and/or single element contingency conditions in 2010 Re-rate portions of two 34kV lines: Sections 180A & 102 Load Growth/ Sub-Area Study 2012 Bishop Street Substation Proposed Low voltages on Section 188 under single element contingencies, violation of 25 MW loss of load criteria Add 2-34 kV breakers, add 5.4 MVAR capacitor bank Load Growth/ Sub-Area Study 2012 Voltage support Proposed Low voltages in the local area under single element contingencies Add 5.4 MVAR capacitor banks at Freeport, E. Deering, N. Gorham S/S (2) Load Growth/ Sub-Area Study 2012Line WorkProposed Two segments overload under normal operating and/or single element contingency conditions in 2012 Rebuild portions of 34.5 kV line Section 188

8 8 8 LSP Projects Need Projected In-Service Date Major Project StatusNeeds AssessmentSolutions Load Growth/ Sub-Area Study 2013 Portland North Area Reliability Study (Cont) Elm Street Substation Proposed Transmission elements experienced overloading (Not needed if Raven Farms is built for MPRP) Bring S164 in/out of Elm St, re-rate S164A Load Growth/ Sub-Area Study 2014 Swett Rd. Substation Proposed Low Voltages in the local area under single element contingencies Add 2-34 kV breakers, rebuild Section 103 Load Growth/ Sub-Area Study 2015 North Yarmouth Substation Proposed Reliability Concerns under single element contingencies New 115/34kV S/S tapped from Sect 166, and 14.8 mi 34.5 kV line to Gray & Freeport with breakers Load Growth/ Sub-Area Study 2017 Swett Road Substation Concept Voltage support is needed Add 5.4 MVAR capacitor bank Load Growth/ Sub-Area Study 2018 Prides Corner Substation Concept Additional voltage support is needed Add an additional 5.4 MVAR capacitor bank

9 9 9 LSP Projects Need Projected In-Service Date Major Project Status Needs AssessmentSolutions Load Growth/ Sub-Area Study2011 Skowhegan Area Reliability Line WorkProposed Overloading under single element contingency conditions Re-rate Section 73 Load Growth/ Sub-Area Study 2011 Study Norridgewock Source Proposed Distribution circuit becoming overloaded, need to bring in a new source to shift load to. Tap Section 73, install 34/34 delta- wye isolating transformer for new distribution supply Load Growth/ Sub-Area Study 2013 Lakewood Substation Expansion Proposed Reliability concerns under single element contingencies Loop Section 241 into a new 115 kV ring bus with 2 nd 115/34.5 kV transformer

10 LSP Projects Need Projected In-Service Date Major Project StatusNeeds AssessmentSolutions Load Growth2011Bath AreaLine WorkProposed Overloads under single element contingency conditions Rebuild 34.5 kV Sections 55 & 58

11 LSP Projects NeedProjecte d In- Service Date Major Project StatusNeeds AssessmentSolutions Load Growth/ Sub-Area Study 2011 Augusta Area Reliability Study Line Re-ratings Proposed Overloaded under normal operating conditions Re-rate 34 kV line Sections 39 & 41 to 212°F thermal limit Load Growth/ Sub-Area Study 2011 Bowman St Substation Under Construction Bowman St 115/34.5 kV transformer overloaded and low 34.5 kV bus voltage, post-contingency Add 2 nd 115/34.5 kV transformer Load Growth/ Sub-Area Study 2015 Coopers Mills Substation Proposed Low voltages following loss of Maxcys 115/34.5 kV transformer Add second 115/34.5 kV transformer at Coopers Mills (Maxcy's) Coordinate w/MPRP

12 LSP Projects Need Projected In-Service Date Major Project StatusNeeds AssessmentSolutions Load Growth/ Sub-Area Study 2011 Berwick - Lebanon Area Reliability Study Bassett Substation Planned Experiencing high load growth, thermal restriction on Section 118 New Bassett Substation Load Growth/ Sub-Area Study 2011Proposed Experiencing high load growth, thermal restriction on Section 118 Add 2 nd 34.5 kV transmission line from Quaker Hill to Bassett Load Growth/ Sub-Area Study 2013 Berwick Substation Proposed Load growth, inadequate 34/12 kV capacity, overloaded distribution circuits Add new Berwick Substation and 34.5 kV transmission line from Bassett Load Growth/ Sub-Area Study 2014 New Lebanon Substation Proposed Load growth in Lebanon area will exceed area capacity Add new Lebanon Substation and 34.5 kV transmission line from Butler’s Corner

13 LSP Projects NeedProjected In-Service Date Major Project StatusNeeds AssessmentSolutions Load Growth/ Sub-Area Study 2011 Camden- Rockland Area Reliability Study Camden Substation Proposed Low voltageAdd 5.4 MVAR 34.5 kV capacitor bank Load Growth/ Sub-Area Study 2011 Park St Substation Proposed Low voltageAdd 5.4 MVAR 34.5 kV capacitor bank Load Growth/ Sub-Area Study 2011 Meadow Rd Substation Proposed Low voltageAdd 10.8 MVAR 34.5 kV capacitor bank

14 LSP Projects NeedProjected In-Service Date Major Project StatusNeeds AssessmentSolutions Load Growth/ Sub-Area Study 2011 Lewiston Auburn Area Leeds Substation Proposed Low voltage and transformer loading at Turner Build a new Leeds 115/34.5 kV distribution substation Load Growth/ Sub-Area Study 2020Reliability Study Gulf Island transformer Upgrade Concept Transformer overload with load growth, with MPRP reinforcements Transformer change- out Load Growth/ Sub-Area Study 2013 Section 148 Cable Replacement Planned 34.5 kV line overload post-contingency Replace cable into Great Falls Substation Load Growth/ Sub-Area Study 2011 Section 72 re-rate Planned 34.5 kV line overload post-contingency Change protection settings

15 LSP Projects NeedProjected In-Service Date Major Project StatusNeeds AssessmentSolutions Load Growth/ Sub-Area Study 2012Saco Bay Area Reliability Study New Vallee Lane & Goosefare Substations ProposedAdditional 115 kV transformer capacity and voltage support is needed in the Saco Bay Area. Loss of Section 193 violates CMP’s loss of load criterion. New 115 kV double- circuit line from Louden to Old Orchard Beach New 115/34.5 kV Substation in Old Orchard Beach & new 115/12 kV substation in Saco.

16 LSP Projects Need Projected In-Service Date Major Project StatusNeeds AssessmentSolutions Load Growth/ Sub-Area Study 2012 Mid-Coast Reliability Study Belfast Voltage Support Proposed Loss of Section 86 exceeds CMP’s loss of load criterion and results in low voltages Add 10.8 MVAR 34.5 kV capacitor bank Part of MPRP (with 115 kV breakers) Load Growth/ Sub-Area Study2012 Waterville/ Winslow Area Reliability Study Line workConcept Overloads under single element contingency conditions Re-rate portions of the 34.5 kV lines Sections 13 and 38. Load Growth/ Sub-Area Study2012 Belgrade Source Concept Reliability and voltage concerns on a very long 34.5 kV distribution circuit out of Rice Rips; need to bring in a new source to shift load. Install a 115/34 kV transformer at North Augusta with new 34.5 kV circuit into the Belgrade area.

17 LSP Projects NeedProjected In-Service Date Major Project StatusNeeds Assessment Solutions Load Growth/ Sub-Area Study 2012 Brunswick Topsham Area Study Line WorkConcept Overloads under single element contingency conditions Re-rate 34.5 KV Section 76 Load Growth/ Sub-Area Study 2012 Upgrade 34/12 kV Transformer Concept Overloads under normal operating conditions Upgrade Brunswick Hydro T1 34/12 kV transformer Load Growth/ Sub-Area Study 2014 Upgrade 34/12 kV Transformers Concept Overloaded under normal operating conditions Upgrade Woolwich T1 34/12 kV transformer Upgrade Topsham T2 34/12 kV transformer Load Growth/ Sub-Area Study 2014 Topsham 115 Substation Concept Change-out transformers to larger capacity to supply local load growth Upgrade Topsham T1 and T3 115/34.5 kV transformers

18 LSP Generation Projects NeedProjected In-Service Date Major Project ProjectStatusNeeds Assessment Solutions Generator Interconnect 2009ISO-NE Queue # 138 In Service (Part A) Part B-will be in service by 10/31/10 Met Developer’s Interconnection Request & Implemented the Recommendations contained in the I.3.9 Proposed Plan Application Rebuild Bigelow Substation Wyman Hydro Substation Upgrades Re-rate Sect 215 Several area capacitor banks Generator Interconnect 2011ISO-NE Queue # 197 PlannedRequest to connect 50.6 MW Wind Farm to new CMP 115 kV Section 270 New 115 kV line Section 270 (old Section 59) New Roxbury Substation Move 115/34 kV transformer from Rumford to Roxbury

19 LSP Generation Projects NeedProjected In-Service Date Major Project ProjectStatusNeeds AssessmentSolutions Generator Interconnect 2012ISO-NE Queue # 272 WithdrawnInterconnection Request for 85 MW Wind Farm to tap into CMP 115 kV Line Section 222 north of Wyman Hydro Substation Not Applicable Generator Interconnect 2012ISO-NE Queue # 215 PlannedInterconnection Request for 50 MW Wind Farm to tap into CMP 115 kV Section 270 north of Rumford 115 kV Substation System Impact Study Complete Generator Interconnect 2012ISO-NE Queue # 244 ConceptInterconnection Request for 117 MW Wind Farm to tie into CMP Wyman Hydro Substation Undergoing System Impact Study

20 LSP Generation Projects NeedProjected In-Service Date Major Project ProjectStatusNeeds AssessmentSolutions Generator Interconnect 2011ISO-NE Queue # 287 ConceptInterconnection Request for 33 MW Wind Farm to tie into CMP 115 kV Line Section 229 between Rumford Substation and Riley Substation Undergoing System Impact Study Generator Interconnect 2012ISO-NE Queue # 290 PlannedInterconnection Request for 20 MW Wind Farm to tie into CMP Woodstock Substation System Impact Study Complete Generator Interconnect 2012ISO-NE Queue # 300 ConceptInterconnection Request for 20 MW Wind Farm to tie into CMP 115 kV Line Section 229 between Rumford Substation and Riley Substation Undergoing System Impact Study

21 LSP Generation Projects NeedProjected In-Service Date Major Project ProjectStatusNeeds AssessmentSolutions Generator Interconnect 2012ISO-NE Queue #310 Tied to Queue #138 ConceptInterconnection Request for 45 MW Wind Farm to tie into Customer owned 115 kV line Section 267 north of Bigelow Substation. Undergoing System Impact Study Generator Interconnect 2012ISO-NE Queue #333 ConceptInterconnection Request for 216 MW Wind Farm to tie into CMP. Three potential interconnection sites to be studied. Undergoing Feasibility Study Generator Interconnect 2012ISO-NE Queue #335 ConceptInterconnection Request for 25 MW biomass generator at existing customer site. Undergoing System Impact Study Generator Interconnect 2011ISO-NE Queue #337 ConceptInterconnection Request to true- up the existing generating plant net output and add a net increase of 26 MW at existing customer site, Section 227. Undergoing System Impact Study

22 LSP Future Studies Major ProjectProjected Study Date StatusNeeds AssessmentSolutions Portland North Area Reliability Study Dec 2010 In Progress Re-affirm timing and need of projects from the original study. Re-assessing transmission and NTA requirements Mid-coast Area Reliability Study Dec 2010 In Progress Re-affirm timing and need of projects from the original study. Re-assessing transmission and NTA requirements Southern Maine Area Reliability Study 2011Concept Contingency processor showed thermal and voltage violations under single element contingencies Conduct area reliability study and assess possible system upgrades Lakes Region Area Reliability Study 2011Concept Contingency processor showed thermal and voltage violations under single element contingencies Conduct area reliability study and assess possible system upgrades

23 Potential NTA Projects Need Projected In-Service Date Major Project ProjectStatusNeeds AssessmentSolutions Load Growth/ Sub-Area Study 2012Portland North Area Reliability Study Falmouth Substation ProposedLow voltages on Section 180 under single element contingencies, violation of 25 MW loss of load criteria Add kV breakers Load Growth/ Sub-Area Study 2015East Deering Substation ProposedAdditional source needed in the area (Coordinate with MPRP) kV substation with 115kV line from Elm St. Load Growth/ Sub-Area Study 2012Camden- Rockland Area Study Highland Substation ProposedIncreased reliability to meet planning loss of load criteria by splitting Section 51 (Warren – Waldoboro). Add 1 mile 34.5 kV line to separate Warren – Waldoboro line Load Growth/ Sub-Area Study 2013Highland Substation ProposedNeed for post-contingent support in the area provided by a new 34 kV line. New 34.5 kV transmission line to Meadow Rd

24 In-Service LSP Projects Need In-Service Date Major Project ProjectStatusNeeds AssessmentSolutions Load Growth/ Sub-Area Study June 2010 Berwick – Lebanon Area Reliability Study High St Substation In service Thermal restrictions on transmission elements Re-rate 34.5 kV Sections114, 112A, 114A & 185 Load Growth/ Sub-Area Study Nov 2010 Lewiston Auburn Area Study Hotel Road Substation Under- Construction Post-contingency 34.5 kV low voltage problems & overloading of Hotel Rd 115/34 kV transformer Install 2 nd 115/34 kV transformer at Hotel Road Load Growth/ Sub-Area Study Jul 2010 Saco Bay Area Reliability Study Louden Substation In service 34.5 kV line overloadRebuild 34.5kV Section 174