POW ER EN G IN EER S, L LC

Transcription

1 POW ER EN G IN EER S, L LC Electrical Engineering, Power, Lighting, Technical Studies and Utility Consulting 37 Fox Den Road Kingston, MA (508) Phone (781) Fax Dave@PowerEngineersLLC.com STERLING MUNICIPAL LIGHT DEPARTMENT 50 MAIN STREET STERLING, MA EH PERKINS 1.169MW DC PV IMPACT STUDY FOR DISTRIBUTION INTERCONNECTION SEPTEMBER 2011

2 POW ER EN G IN EER S, L LC Electrical Engineering, Power, Lighting, Technical Studies and Utility Consulting 37 Fox Den Road Kingston, MA (508) Phone (781) Fax Dave@PowerEngineersLLC.com Mr. Sean Hamilton September 12, 2011 Sterling Municipal Light Department 50 Main Street Sterling, MA Subject: Sterling Municipal Light Department EH Perkins 1.169MW DC PV Feasibility Study for Distribution Interconnection Dear Alan: Power Engineers, LLC has completed a detailed feasibility impact study for the distribution interconnection of the proposed PV project at EH Perkins off of Jewett Road. The attached report contains a review of the preferred route that has been established for a 13.8kV interconnection of the 1.169MW (DC ) PV project to connect the existing 13.8kV circuit owned by SMLD. The results of the study are favorable for the interconnection of the proposed PV project to the existing 13.8kV 1504 Circuit, off of Jewett Road, tapped of Route 62. If you have any questions, or require additional information, please feel free to give me a call. Sincerely, David J. Colombo, P.E. Principal

3 Sterling Municipal Light Department EH Perkins PV Project Feasibility Study for Distribution Interconnection September 2011 TABLE OF CONTENTS SECTIO DESCRIPTIO 1 Executive Summary 2 Existing Infrastructure 3 Proposed Installation 4 Computer Analysis 5 Conclusions / Recommendations Attachments 1. NexAmp Drawings a. S0.1 Site Plan b. E7.4 - One-Line Diagram c. E7.5 Ductbank & Pole Details d. E7.6 - Transformer Pad Details e. E7.7 - Grounding Plan 2. SMLD System Load and Feeder Data ( ) 3. Computer Model one-line diagram 4. Computer model input data 5. Time Current Curves (overcurrent protection)

4 EXECUTIVE SUMMARY A detail Feasibility Study for Distribution Interconnection of the EH Perkins 1.0MW (AC) / 1.169MW (DC) PV project (hereafter referred to as the Study) was conducted for the Sterling Municipal Light Department (SMLD). The purpose of the Study was to review the technical issues related to thermal capacity, voltage performance, short circuit and protection for the SMLD 13.8kV distribution circuit to absorb the power output of the PV System, to be installed on Jewett Road in Sterling, MA. Nexamp has proposed to interconnect the new 1.0MW PV System to the Jewett Road location to the existing 13.8kV circuit. This is the SMLD 1504 Circuit that runs from the Chocksett Substation to Worcester Road to Princeton Road to Jewett Road. The existing distribution on Jewett Road is single-phase and would need to be upgraded to three-phase as part of this project. The results of the Study contained herein indicate that the proposed interconnection is acceptable. Thermal loading of existing SMLD overhead primary 13.8kV wire on the 1504 Circuit is acceptable with the 1.0MW proposed PV System in operation and the SMLD system under peak load conditions. The SMLD 1504 Circuit is comprised of 477kcmil and #1/0Awg aluminum conductors. Existing equipment loading, including the upstream substation transformer is also acceptable give present ratings. During light load conditions with the PV System in operation, the voltages on the system are within industry limits and voltage drops through the wire sections are acceptable. Short circuit and power factor contributions are also considered acceptable and should not cause any significant deviations to the SMLD system. The EH Perkins / Nexamp project should provide sufficient power factor control at the PV System site or on the 13.8kV circuit to maintain the power factor at the Point of Common Coupling (PCC) to pre-project conditions. A voltage flicker analysis was also performed and determined that the limits are below the industries accepted standard IEEE It is recommended to proceed with the proposed project and commence with detailed design and construction of the new 13.8kV line construction along Jewett Road to the primary of the project site equipment. In addition, it is recommended to proceed with the PV System vendor to resolve the technical issues addressed in this report, including protective requirements to protect the SMLD system from islanding. SMLD Feasibility Study for PV System Interconnection September 2011 Page 1

5 EXISTING INFRASTRUCTURE The existing SMLD system is presently served from the Chocksett Substation. This substation is a 115kV-13.8kV step-down substation. The Substation is supplied by two (2) National Grid 115kV circuits, designated the O-141 and P-142. These transmissions lines tap and feed into two step-down substation transformer, each rated 12/16/20/22.4MVA. The secondary of the transformers each feed into a 2000A, 13.8kV substation bus. Each bus connects in a normally open bus-tie configuration to two feeders. Transformer No. 1 feeds the 1503 and 1504 Circuits, and Transformer No. 2 feeds the 1501 and 1502 Circuits. The available short circuit values on the two 115kV transmission lines from National Grid that serves the SMLD Chocksett Street Substation. The values are listed below. Short Circuit values National Grid Transmission Line P142: 1LG: A= 5.990kA X/R ratio= LG: A= kA X/R ratio= Line O141: 1LG: A= 6.007kA X/R ratio= LG: A= kA X/R ratio= The SMLD system has a system peak just over 13MW (13,284kW) recorded this past July 2011, before peak shaving generation is considered. The monthly system peak for the begging of 2011 is as follows (not considering peak shaving): Figure 1 SMLD Peak System Load Month Peak Demand kw January ,850 kw February ,558 kw March ,072 kw April ,067 kw May ,044 kw June ,886 kw July ,284 kw During the recent summer peak (July 2011), the typical distribution of load amongst the four 13.8kV feeders was as follows: SMLD Feasibility Study for PV System Interconnection September 2011 Page 2

6 1501 Circuit 36.2% 1502 Circuit 14.4% 1503 Circuit 18.0% 1504 Circuit 31.3% These values listed above will be the basis for the peak load system model. Data from has been provided by SMLD and reviewed as part of this project. The 1504 Circuit feeds from the Substation along Leominster Road, to Meetinghosue Road, to Worcester Road, to Princeton Road. Off of Princeton Road (Route 62) is the tap to Jewett Road. Presently the infrastructure includes a tap off of Princeton Road (Pole #20) to Jewett Road with three-phase primary (#1/0Awg tree wire TW). The three-phase primary extends to Pole #3 Jewett Road. Beyond that the primary is only single-phase and will need to be upgraded as part of this project. Below (Figure 2) shows the SMLD Three-Phase Circuit Map with the area of the proposed interconnection noted. SMLD Feasibility Study for PV System Interconnection September 2011 Page 3

7 Figure 2 SMLD Three-Phase System One-Line Proposed Interconnection Point to Jewett Road & PV project (P20) SMLD Feasibility Study for PV System Interconnection September 2011 Page 4

8 PROPOSED INSTALLATION The proposed installation includes the installation of a 1.0MW AC rated PV system. The one-line diagram provided by Nexamp shows a primary underground 15kV cable connection to a riser pole, owned by SMLD. The underground cable, which is listed as 15kV #1/0Awg aluminum would then interconnect a new padmount primary metering cabinet, and a 1000kVA padmount transformer. This transformer would be rated 13.8kV primary and 480Y/277V secondary. The secondary of the transformer is shown connect with 4 sets of 600kcmil conductors to a 2000A 480V switchboard with main disconnect, customer REC metering section and 3 branch feeder breakers. There are 2-800A breakers shown, each one to connect to a 500kW inverter and a smaller 20A, 2-pole breaker to connect to a 120/240V panelboard (fed through a 7.5kVA transformer), for local loads (lighting, receptacle, data acquisition, etc.). The SMLD work for the proposed installation would be to upgrade the existing #1/0Awg aluminum overhead tree wire primary from single-phase to three-phase to the project interconnection point, which would be Pole #5 Jewett Road. The proposed PV system, rated at 1.0MW is likely to inject a maximum of 45 amps at 13.8kV into the SMLD system. The existing #1/0Awg aluminum primary wire is rated appropriately on a thermal basis. In reviewing the proposed Nexamp design there are several concerns, or issues that should be addressed: 1. The proposed 2000A secondary switchboard is shown connected with 4 sets of 600kcmil copper conductors from the padmount transformer primary. For 2000A rating, the cables should be 5 sets, not 4 sets. If the intent is a 1600A rated switchboard, then a fused disconnect main, or circuit breaker main, rated at 1600A should be provided, in compliance with the 2011 NEC. 2. The customer should review the proposed design with the local wire inspector, to determine if ground fault protection is required at the switchboard. The 2011 NEC requires ground fault protection on all 480V service entrance equipment rated over 1000A, which this project is. 3. The proposed padmount transformer is shown as a wye-ground / wye-ground winding configuration. It is recommended that this be changed to a delta primary and wye-grounded secondary configuration. The delta / wye transformer configuration is more common, and provided additional benefits to SMLD. First it will limit the pass-through of ground fault current to the primary system from a secondary contribution. In addition the delta primary winding will limit the contribution of damaging 3 rd and 5 th harmonic currents produced by the project to the SMLD system. SMLD Feasibility Study for PV System Interconnection September 2011 Page 5

9 4. The proposed one-line diagram does not show anti-islanding protection, as is typically required of DG systems. This type of protection insures that the system is disconnected quickly when the SMLD feeder is de-energized and that the PV system does not try to feed local loads in an island for a period of time. The project should provide its protective settings of the inverters for review, and show a level of utility-grade protection for anti-islanding. This will be discussed in more detail in the protective section in this report. The riser pole on the PV System site would include a three-phase 15kV group-operated air-break (GOAB) switch to allow the PV System to be isolated with a visible break. Primary metering will be installed within 50 feet of the primary riser, with the adjacent 1000kVA padmount transformer. Fused cutouts should also be included at the site, near the riser pole location to protect the metering and underground cable. The maximum expected output of the PV Systems is 45 amps at 13.8kV (assuming power factor). As will be detailed later, protection should also be installed at the intersection of Princeton Road and Jewett Road, as there is no in-line protection between Princeton Road at this location and the upstream, Chocksett Substation. The attached one-line diagram (Drawing E7.4) illustrates the proposed connection between the PV System, on the project site. SMLD Feasibility Study for PV System Interconnection September 2011 Page 6

10 COMPUTER ANALYSIS A detailed computer analysis was completed for the normal proposed configuration of the two (2) 500kW inverters and 1000kVA step-up transformer interconnection to the SMLD system through a new 13.8kV riser and primary line extension to the SMLD 1504 Circuit. The computer modeling was completed with the PowerTools software suite by SKM Systems Analysis, Inc. Cases Modeled The following three (3) individual cases have been examined: Case #1 This is the Base Case with the existing 1504 Circuit from SMLD connected to a new 13.8kV primary tap (#1/0Awg aluminum tree wire) to Pole #5 Jewett Road. Maximum feeder loads are considered on Circuit 1504, based on July 2011 data. No PV Systems are in-service in this case. Case #2 This Case is the Base Case with the addition of the 2-500kW inverters on-line. The 1504 Circuit is considered at its peak load condition. Case #3 This Case is the Base Case with the addition of the 2-500kW inverters on-line at full output. The 1504 Circuit is considered at its light load condition, which would occur on weekends, etc. Data Collection Along with a physical survey completed in September of the existing pole lines in Sterling, the following information was requested from SMLD, reviewed and has been the basis for the computer modeling: a. Circuit Maps, showing the existing distribution circuits that could connect to the proposed wind project. b. Substation One-Line for the substations related the distribution circuits that could connect to the proposed wind project. c. Wire Sizes for distribution circuits, if not shown on circuit maps. d. Protective Settings for substation related the distribution circuits that could connect to the proposed wind project e. Capacitor locations, sizes and settings, on the distribution circuits that could connect to the proposed wind project. SMLD Feasibility Study for PV System Interconnection September 2011 Page 7

11 f. Fuse sizes, locations and settings on the distribution circuits that could connect to the proposed wind project. g. Recloser locations, ratings and settings on the distribution circuits that could connect to the proposed wind project. h. Feeder and Substation Transformer loading. Assumptions The following assumptions were made for the computer model: The inverters for the PV project as assumed to be 500kW AC rated output with a power factor, normally at unity (1.0) with excursions of no more than +/ The computer model is of just the AC portion of the system, as the DC system will cause no negative impacts on the SMLD 13.8kV system. The PV Systems will step up through 1000kVA, 5.75% impedance (ANSI standard) padmount transformers from the PV System generator 480 volts. The SMLD peak July loading is assumed to be 13,284kW, without the peak shaving generation in service. System power factor is assumed to be 0.98, based on recent peak load data. The SMLD system feeders are divided by load, with 36.2% on 1501, 14.4% on 1502, 18.0% of 1503 and 31.3% on The substation load tap changers are assumed to regulate the secondary 13.8kV terminals to %, close to 14.1kV. The peak load on 1504 Circuit is 4159kW, based on assumptions from July data. Riser pole fuses at the PV site were assumed to be 50A (k-speed). Tap fuses at Princeton Road at Jewett Road were assumed to be 80A (k-speed). Substation relays are set for 360A phase pickup on the 1504 feeder. The following assumption of load split on the 1504 Circuit is being used in the computer model for a lumped load. o Load data at Pole 53 Princeton, Pole 53 Beaman and Pole 46 Worcester Road is based on actual 7/8/2011 readings, as a percentage of the total. o The 9 feeder sections modeled were loaded at the end of each section based on the length of the feeder in relation to the total feeder length, large spot loads and existing system data available. SMLD Feasibility Study for PV System Interconnection September 2011 Page 8

12 Load Flow & Voltage Drop Analysis A load flow and voltage drop analysis was conducted to determine if the addition of a 1.0MW PV System would have a negative or unacceptable effect on the SMLD distribution system. The load flow examined thermal loading limits of the existing and new conductors, transformers and other equipment. The voltage drop analysis examined the system voltage with and without the PV System on-line. Both of these analyses were conducted at peak and minimum system loads on the 1504 feeder. The results of the load flow study are summarized below. Peak system load is based on SMLD data for a recent system peak day, 7/22/2011, with the following feeder loading (out of Chocksett Substation): 1501 Circuit 1502 Circuit 1503 Circuit 1504 Circuit MW MW MW MW The system configuration is assumed to be in the normal state with both transformers in service at the Chocksett Substation, all capacitors in service normally (system power factor 0.98, as recorded during July peak). A review of SMLD data for the past few years shows night time system load being as low as 4.5MW during spring and fall months. Obviously the PV system cannot operate during the 3:00AM 4:00AM when the system load is at its lowest. Based on the data provided, an assumed light system load of 6.5MW was modeled, as could occur on a weekend, holiday or other period of light load. SMLD Feasibility Study for PV System Interconnection September 2011 Page 9

13 LOAD FLOW CASE RESULTS Location Case #1 Case #2 No PV System Peak System Load 1.0MW PV System Peak System Load Case #3 1.0MW PV System Light System Load Chocksett Substation Trans 1 (22MVA rated) 1504 Feeder Main Out of Substation (477kcmil wire) 1504 Feeder Intersection of Worcester & Princeton Roads (towards Worcester Rd) 1504 Feeder Intersection of Worcester & Princeton Roads (towards Princeton Rd) 6.55MW 5.43MW 2.08MW 4.135MW / 174Amps 3.02MW / 126Amps 0.91MW / 37Amps 1.31MW / 55A 1.31MW / 55Amps 0.64MW / 27Amps 1.62MW / 69A 0.53MW / 22Amps 0.30MW / 13Amps (towards SMLD) Jewett Road tap off of Princeton Road (#1/0awg wire) 0MW / 0A 1.0MW / 46Amps (towards SMLD) 1.0MW / 46 Amps (towards SMLD) The voltage drop analysis is used to determine if the system voltage at any point on the new interconnection or the existing SMLD 13.8kV 1504 circuit will be below or above the industry +/- 5% limits, as dictated by ANSI C84.1 American National Standard for Electric Power Systems and Equipment Voltage Ratings (60Hz) and other similar requirements. For the voltage drop analysis all capacitor banks on the 1504 circuit are assumed to be in service. The results of the voltage drop analysis are summarized below. SMLD Feasibility Study for PV System Interconnection September 2011 Page 10

14 VOLTAGE DROP CASE RESULTS Location Case #1 Case #2 No PV System Peak System Load 1.0MW PV System Peak System Load Case #3 1.0MW PV System Light System Load Chocksett Substation Trans 1 (22MVA rated) 1504 Feeder Main Out of Substation (477kcmil wire) 14,108V 14,157V 14,180V 14,106V 14,156V 14,179V 1504 Feeder Intersection of Worcester & Princeton Roads 1504 Feeder Pole46 Worcester Rd 1504 Feeder Princeton at Beaman 1504 Feeder Jewett Road 13,880V 14,006V -0.9% VD 13,849V 13,976V VD 13,838V 13,976V -0.99% VD 13,865V 14,015V -1.01% VD 14,144V -0.81% VD 14,129V -0.82% VD 14,136V -0.90% VD 14,160V -0.98% VD The results of the load flow and voltage drop analysis indicate that during peak and light load conditions on the feeder, there are no thermal overloads of wire, transformers, etc. In addition there are no voltage violations outside of acceptable range. The addition of the PV System raises the primary voltage about 150 volts (about 1%) near the site and should not create any high voltage conditions during light load periods. Although there are a number of various cases that could be examined the cases selected cover the normal operation of the 1504 Circuit. The performance should not be impacts in a negative way by single contingencies when load is transferred to other distribution circuits. As a litmus test, the loss of SMLD Chocksett Substation Transformer No. 1 was simulated under peak load conditions (Case #2 above). The remaining Transformer No. 2 is capable of supporting the expected 13.2MW of peak load, and voltage variations are similar to the Case #2 with both transformers in service. The 13.8kV substation bus is about 50 volts below the case with both transformers in service. SMLD Feasibility Study for PV System Interconnection September 2011 Page 11

15 Voltage Flicker Analysis Voltage Flicker is defined as a noticeable or irritation fluctuation of voltage that can cause mis-operation of equipment. The industry standard for interconnection of distributed generation IEEE 1547 addresses the requirements for flicker on new projects as follows: IEEE 1547 states that: Synchronization - The DR unit shall parallel with the Area EPS without causing a voltage fluctuation at the PCC greater than ±5% of the prevailing voltage level of the Area EPS at the PCC, and meet the flicker requirements of Limitation of flicker induced by the DR. The DR shall not create objectionable flicker for other customers on the Area EPS. Flicker is considered objectionable when it either causes a modulation of the light level of lamps sufficient to be irritating to humans, or causes equipment mis-operation DR is the Distributed Resource; PCC is the Point of Common Coupling and EPS is the Electric Power System Flicker is based on measurements in the voltage amplitude, i.e., the duration and magnitude of variations. The table below shows the magnitude of maximum voltage changes allowed with respect to the number of voltage changes per second Voltage Fluctuation Versus Duration Curve The industry now uses a guideline of a 2.0% voltage fluctuation as being noticeable and causing irritation or possible equipment operation, for most projects. Since the proposed PV Systems are not likely to all come on line at the same time, the worst SMLD Feasibility Study for PV System Interconnection September 2011 Page 12

16 case for voltage flicker would occur if the PV Systems all trip off line at the same time, from full output. The results of the flicker modeling are summarized below, for a full load (Case #2) and light load (Case #3) condition. The voltage variation was modeled at the PCC, which is on Jewett Road. The voltage fluctuation would occur quicker than voltage regulating devices (LTC, capacitors, etc.) could react. VOLTAGE FLICKER RESULTS Location Case #2 1.0MW PV System Peak System Load Case #3 1.0MW PV System Light System Load Pre-Trip Voltage Jewett Road at Princeton Road Post-Trip Voltage Jewett Road at Princeton Road 14,035V 14,177V 13,901V 14,041V Voltage Variation 134V (0.96%) 136V (0.97%) The results of the voltage flicker analysis are acceptable with short term voltage fluctuations below 2.0% when all three PV Systems trip off line at full output, before other voltage regulating equipment can react. This level of fluctuation should be below the level or perception. Power Factor Analysis The power factor performance of the proposed PV System interconnection has been reviewed. The proposed inverters should have the ability to maintain a nominal 1.0 unity power factor, with a possible deviation of no more than 0.95 leading to 0.95 lagging. The computer model assumed this standard deviation in power factor. The computer modeling has assumed that all of the capacitor banks are in service during peak load conditions. All feeder loads has been assumed to have a 0.98 power factor. The results of this analysis shows that for Case #1 under peak load, without the PV Systems, the power factor at the substation is 0.99 due to the nearby 1200kVAR capacitor bank. With the PV Systems on-line, the power factor at the Town Line drops to As mentioned earlier, the PV System modeling is conservative regarding the var limits & control and the power factor in reality should be closer to unity here. The power factor at the Chocksett Substation is acceptable with the PV system in operation as summarized below. SMLD Feasibility Study for PV System Interconnection September 2011 Page 13

17 POWER FACTOR RESULTS Location Case #1 Case #2 No PV System Peak System Load 1.0MW PV System Peak System Load Case #3 1.0MW PV System Light System Load Chocksett Substation 13.8kV Bus Feeder Intersection of Worcester & Princeton Roads 1504 Feeder Pole46 Worcester Rd 1504 Feeder Princeton at Beaman 1504 Feeder Jewett Road As can be seen the power factor performance is virtually unaffected by the addition of the 1MW PV system. No additions of capacitor banks are required due to the project. System Power Factor Theory All electric equipment requires "VARs" - a term used to describe the reactive or magnetizing power required by the inductive characteristics of electrical equipment. These inductive characteristics are more pronounced in motors and transformers, and therefore, can be quite significant in industrial facilities. The flow of VARs, or reactive power, through a watt-hour meter will not affect the meter reading, but the flow of VARs through the power system will result in energy losses on both the utility and the industrial facility. Some utilities charge for these VARs in the form of a penalty, or KVA demand charge, to justify the cost for lost energy and the additional conductor and transformer capacity required to carry the VARs. In addition to energy losses, VAR flow can also cause excessive voltage drop, which may have to be corrected by either the application of shunt capacitors, or other more expensive equipment. SMLD Feasibility Study for PV System Interconnection September 2011 Page 14

18 Power Factor Triangle The power triangle shown in figure above is the simplest way to understand the effects of reactive power. The figure illustrates the relationship of active (real) and reactive (imaginary or magnetizing) power. The active power (represented by the horizontal leg) is the actual power, or watts that produce real work. This component is the energy transfer component. The reactive power or magnetizing power, (represented by the vertical leg of the upper or lower triangle) is the power required to produce the magnetic fields to enable the real work to be done. Without magnetizing power, transformers, conductors, motors, and even resistors and capacitors would not be able to operate. Reactive power is normally supplied by generators, capacitors and synchronous motors. The longest leg of the triangle (on the upper or lower triangle), labeled total power, represents the vector sum of the reactive power and real power components. Electric power engineers often call total power (kva, MVA) - apparent power, or complex power. Some utilities measure this total power, (usually averaged over a 15 minute load period) and charge a monthly fee or tariff for the highest fifteen minute average load reading in the month. In the power triangle shown above, the reactive power component is decreased by adding shunt capacitors, and the total power will also decrease. This is shown by the decreased length of the dashed lines in the power triangle as the reactive power component approaches zero. Therefore, adding capacitors, which will supply reactive power locally, can reduce total power and monthly kva demand. The ratio of the real power to the total power is called power factor. As the angle gets larger (caused by increasing reactive power) the power factor gets smaller. In fact, the power factor can vary from 0.0 to 1.0, and can be either inductive SMLD Feasibility Study for PV System Interconnection September 2011 Page 15

19 (lagging) or capacitive (leading). Capacitive loads are drawn down, and inductive loads are drawn up on the power triangle. Most industrial customers normally operate on the upper triangle (inductive or lagging triangle). As capacitance is added, the length of reactive (inductive) power leg is shortened by the number of capacitive kvar that were added. If the number of capacitive kvar added exceeds the inductive kvar load, operation occurs on the lower triangle. This is commonly referred to as over compensation, and higher system voltages can result. Short Circuit Review A detailed short circuit review was completed to determine if the addition of the proposed PV Systems would have an effect on the fault interrupting ratings of the existing SMLD equipment. The short circuit review was completed, based on equipment information and drawings provided by the client and manufacturers. The objective was to calculate the available three-phase and line-to-ground fault currents under worst case (bolted fault) conditions and compare these values to the published device interrupting ratings. The maximum symmetrical fault currents occur during the first 1/2 cycle after a fault. The short circuit review has been performed based on the intent of the following applicable industry standards: ANSI/IEEE Std C Application Guide for AC High-Voltage Circuit Breakers Rated on a Symmetrical Current Basis ANSI/IEEE Std C Low-Voltage AC Power Circuit Breakers Used in Enclosures IEEE Std 141 Recommended Practice for Electric Power Distribution in Industrial Facilities. IEEE Std Recommended Practice for Industrial and Commercial Power Systems Analysis Two separate short circuit cases have been examined as part of this Study: Case No. 1 Case No. 2 Base Case No PV System running. 1.0MW PV Systems running. Maximum load on 1504 feeder. The results for the minimum load case (Case #3) would be similar to Case #2. For each case, the initial symmetrical and asymmetrical short circuit currents during the first one-half cycle after a bus fault occurs were calculated. This provides a worst case calculation to be used for comparison with equipment ratings. See Figure below. SMLD Feasibility Study for PV System Interconnection September 2011 Page 16

20 imp peak fault current, first 1/2 cycle dice dc decaying component of fault current I ratio of pre-fault voltage to Thevenin equivalent impedance Figure Short Circuit Current Versus Time After Fault Occurs. The following faults were simulated and calculated for each (3-phase) equipment: Three-phase fault, Single line-to-ground fault, Double line-to-ground fault and Line-to-line fault. The results of the short circuit review as summarized in the table below. The existing fault current on Princeton Road near the project site is about 2535 amps. This value is well below the 10kA distribution limit for most conventional polemount equipment. The addition of the inverters should add no more than 1800A at 480V per inverter (based on an assumed 3X full load amps), which translates to no more than 125A additional fault current on the SMLD 13.8kV system, or a 4.9% increase theoretical maximum. This should create no additional impact for SMLD equipment, or its customer s equipment. Actual inverter information should be provided by the vendor to confirm the maximum short circuit contribution. SMLD Feasibility Study for PV System Interconnection September 2011 Page 17

21 Location Short Circuit Summary Table Case#1 No PV System Running Case#2 1.0MW PV System Princeton Road at Jewett Road 2,535 ka 3-phase 2,652 ka 3-phase (4.6% increase) SMLD Chocksett Substation ka 3-phase ka 3-phase (2.0 increase) Protective Coordination Review A review of the existing protective devices on the SMLD 1504 Circuit was completed to determine if any upgrades will be required as part of the PV System interconnection. Presently the existing 1504 Circuit is protected at the Chocksett Substation by SEL overcurrent relays which operate the 13.8kV substation circuit breakers (13.8kV). The overcurrent protection includes phase and ground protection with time overcurrent (51) and instantaneous settings (50). The existing 1504 substation relays are set for 360A phase overcurrent pickup and 144A ground overcurrent pickup. As mentioned there is no other protection between the substation the proposed point of interconnection presently. The estimated current flow into the SMLD system at the town line during full PV System output with no SMLD load tapped off the 13.8kV line would be approx. 45 amps at 13.8kV. This is well below the pickup settings of the existing SMLD devices and no relay or recloser settings changes are recommended. SMLD has indicated that its preference will be to install fused cut-outs for the tap from Princeton Road to Jewett Road, as is convention for three-phase taps. The recommended fuse size is 80A for the tap to Jewett Road, and the recommended fuse size is 50A at the riser pole, to protect the 1000kVA transformer and the primary cable. The proposed time current characteristic (TCC) curve (in the back of the report) illustrates the coordination with the inrush and damage curves of a typical 1000kVA transformer of standard impedance. The proposed transformer should be provided with standard bay-o-net fuses, sized by the manufacturer to protect the transformer from overload. The riser pole fuses will protect the underground primary cable (#1/0Awg aluminum) as well as the primary metering cabinet. For this project the recommended CT ratio should be 35:5, as the CT s will have an overload factor of at least 1.25X. This will provide accuracy for periods of light generation. SMLD Feasibility Study for PV System Interconnection September 2011 Page 18

22 The project and Nexamp should provide documentation showing the coordination of their 800A 480V circuit breakers with these fuses and the proposed 1000kVA transformer. The Protective Coordination Review was completed based on the intent of the following applicable industry standards: IEEE Std Recommended Practice for Protection and Coordination of Industrial and Commercial Power Systems IEEE Std Recommended Practice for Applying Low-Voltage Circuit Breakers Used in Industrial and Commercial Power Systems. IEEE Std Recommended Practice for Industrial and Commercial Power Systems Analysis The proposed design and drawings do not include protective settings, or settings for antiislanding protection. SMLD has published Interconnection Requirements for Distributed Generation. This document includes the following requirements that should be adhered to and demonstrated by the project: Voltage Regulation The DR [distributed resource] shall not actively regulate the voltage at the PCC [unless required by NEPOOL s operating procedures]. The DR shall not cause the Area EPS service voltage at other Local EPSs to go outside the requirements of A SI C , Range A. Surge Withstand Performance The interconnection system shall have the capability to withstand voltage and current surges in accordance with the environments defined in IEEE Std C or IEEE C as applicable. Voltage The protection functions of the interconnection system shall detect the effective (rms) or fundamental frequency value of each phase-to-phase voltage, except where the transformer connecting the Local EPS to the Area EPS is a grounded wye-wye configuration, or single phase installation, the phase-to-neutral voltage shall be detected. When any voltage is in a range given in Table 1, the DR shall cease to energize the Area EPS within the clearing time as indicated. Clearing time is the time between the start of the abnormal condition and the DR ceasing to energize the Area EPS. For DR less than or equal to 30 kw in peak capacity, the voltage set points and clearing times shall be either fixed or field adjustable. For DR greater than 30 kw the voltage set points shall be field adjustable. SMLD Feasibility Study for PV System Interconnection September 2011 Page 19

23 Frequency When the system frequency is in a range given in Table 2, the DR shall cease to energize the Area EPS within the clearing time as indicated. Clearing time is the time between the start of the abnormal condition and the DR ceasing to energize the Area EPS. For DR less than or equal to 30 kw in peak capacity, the frequency set points and clearing times shall be either fixed or field adjustable. For DR greater than 30 kw, the frequency set points shall be field adjustable. Table 2 Interconnection system response to abnormal frequencies DR size Frequency range (Hz) Clearing time (s) 30 kw > < > 30 kw > < ( ) adjustable setpoint < a DR 30 kw, maximum clearing times; DR > 30 kw, default clearing times Harmonics When the DR is serving balanced linear loads, harmonic current injection into the Area EPS at the PCC shall not exceed the limits stated in Table 3 IEEE Std The harmonic current injections shall be exclusive of any harmonic currents due to harmonic voltage distortion present in the Area EPS without the DR connected. Based on these requirements and typical requirements placed on other similar projects in MA by investor-owned utilities, the proposed project shall have the following requirements placed upon it: 1. The proposed padmount transformer shall be delta on the primary and wye-ground on the secondary to limit harmonic contributions to the primary. 2. The proposed transformer shall be provided with standard under-oil fusing to protect the transformer from overloads. 3. The project shall confirm that ground fault is not required on its 2000A 480V service entrance equipment, or if required by the NEC and the local inspector, revise their design to include it. 4. The project shall install a dedicated utility-grade relay to prevent islanding and detect fluctuations in voltage and frequency. This relay shall meet the surge SMLD Feasibility Study for PV System Interconnection September 2011 Page 20

24 requirements for hardened utility-grade equipment as set forth in ANSI C A SEL-547 or other similar relay is recommended to be installed on each inverter, at the switchboard level, or in a primary vacuum switch. 5. The following settings for the under/over voltage and frequency are recommended to be in accordance with the requirements above, other standards, such as NPCC under-frequency load shedding and typical utility practice. SMLD Feasibility Study for PV System Interconnection September 2011 Page 21

25 Proposed Protective Relay Settings for Anti-Islanding Protection SMLD Feasibility Study for PV System Interconnection September 2011 Page 22

26 CONCLUSIONS / RECOMMENDATIONS The results of the feasibility study for the proposed PV System interconnection of new 1.0MW PV System with the existing SMLD 1504 Circuit is favorable. There are no appreciable impacts to system voltage performance, thermal loading and short circuit contributions. The proposed interconnection to the Jewett Road section of Princeton Road on the existing SMLD 1504 circuit is recommended, as this is the closet and most accessible point on the SMLD system. 1. Load Flow There are no thermal violations with the proposed installation of the PV System (2 x 500kW inverters) connecting to the existing SMLD 1504 Circuit. The SMLD will need to extend three-phase primary to Pole #5 Jewett Road to facilitate the interconnection. 2. Voltage Drop The voltage drop with the additional power flow due to the proposed PV System produces acceptable voltage drop (less than 3% per line section). No upgrades to the SMLD system are recommended to mitigate voltage issues. 3. Voltage Flicker The voltage flicker which would occur from a sudden disconnect of the PV System from the 13.8kV system does not result in objectionable voltage flicker. The flicker is well below 2%, which is the industry limit. No upgrades to the SMLD system are recommended to facilitate the interconnection. 4. Power Factor - The results of the power factor analysis show acceptable power factor on the SMLD system due to the interconnection and the PV System var requirements during full output. The inverters shall demonstrate a power factor variation of no greater than 0.95 lagging to 0.95 leading. 5. Protective Coordination Review There are no changes required to the existing protective settings of SMLD equipment due to the interconnection of the PV System proposed. New fuses are recommended at the three-phase tap on Princeton Road (80A), along with the new riser pole (50A). The project needs to include a utility-grade relay to address anti-islanding concerns and satisfy the SMLD interconnection requirements, which are similar to other utilities in MA. Proposed settings have been provided. Low-Voltage ground fault requirements also need to be addressed by the project, to show NEC compliance. SMLD Feasibility Study for PV System Interconnection September 2011 Page 23

27 ATTACHMENTS 1. NexAmp Drawings a. S0.1 Site Plan b. E7.4 - One-Line Diagram c. E7.5 Ductbank & Pole Details d. E7.6 - Transformer Pad Details e. E7.7 - Grounding Plan 2. SMLD System Load and Feeder Data ( ) 3. Computer Model one-line diagrams 4. Computer model input data 5. Time Current Curves (overcurrent protection) SMLD Feasibility Study for PV System Interconnection September 2011 Page 24

28 DATE 01/03/11 TIME 1:30 PM WEATHER SUNNY TEMP 40 FORMULAS Full Load MW = (((Ave A * V * Sqrt(3))/1000)/1000) TOTAL SYSTEM (MW) 7.6 AMPS A AMPS B AMPS C AMPS A AMPS B AMPS C MW METER 4.6 MW METER 3 VAR METER 0.1 VAR METER 0.7 TRANSMISSION VOLTS TRANSMISSION VOLTS BUS 1 VOLT METER BUS 2 VOLT METER (SUB) 1501 (SUB) AMPS A AMPS B AMPS C AVE AMPS AMPS A AMPS B AMPS C AVE AMPS BUS VOLTAGE 14,200 BUS VOLTAGE 14, TOTAL SYSTEM % 23.30% TOTAL SYSTEM % 26.86% 1504 (SUB) 1502 (SUB) AMPS A AMPS B AMPS C AVE AMPS AMPS A AMPS B AMPS C AVE AMPS BUS VOLTAGE TOTAL SYSTEM % POLE 38 CHOCKSETT ROAD 14,200 BUS VOLTAGE 14, % TOTAL SYSTEM % 16.50% POLE 1 PRATTS JUNCTION ROAD AMPS 41-B AMPS 42-C AMPS 43-A AVE AMPS AMPS 41-A AMPS 42-C AMPS 43-B AVE AMPS TOTAL SYSTEM % POLE 53 PRINCETON ROAD 13,800 13, % TOTAL SYSTEM % 8.39% POLE 10 HEYWOOD ROAD AMPS 41-A AMPS 42-C AMPS 43-B AVE AMPS AMPS 41-A AMPS 42-C AMPS 43-B AVE AMPS TOTAL SYSTEM % POLE 53 BEAMAN ROAD 13,800 13, % TOTAL SYSTEM % 4.19% POLE 3-2 LEGATE HILL ROAD AMPS 41-B AMPS 42-C AMPS 43-A AVE AMPS AMPS 41-A AMPS 42-C AMPS 43-B AVE AMPS TOTAL SYSTEM % POLE 46 WORCESTER ROAD 13,800 13, % TOTAL SYSTEM % 5.87% POLE 8 MAPLE STREET AMPS 41-A AMPS 42-C AMPS 43-B AVE AMPS AMPS 41-B AMPS 42-C AMPS 43-A AVE AMPS TOTAL SYSTEM % 13,800 13, % TOTAL SYSTEM % 7.13% POLE 5 WILES ROAD AMPS 41-A AMPS 42-C AMPS 43-B AVE AMPS TOTAL SYSTEM % 13, %

29 DATE 02/14/11 TIME 1:00 PM WEATHER OVERCAST TEMP 50 FORMULAS Full Load MW = (((Ave A * V * Sqrt(3))/1000)/1000) TOTAL SYSTEM (MW) 6.7 AMPS A AMPS B AMPS C AMPS A AMPS B AMPS C MW METER 4 MW METER 2.7 VAR METER 0 VAR METER 0.6 TRANSMISSION VOLTS TRANSMISSION VOLTS BUS 1 VOLT METER BUS 2 VOLT METER (SUB) 1501 (SUB) AMPS A AMPS B AMPS C AVE AMPS AMPS A AMPS B AMPS C AVE AMPS BUS VOLTAGE 14,200 BUS VOLTAGE 14, TOTAL SYSTEM % 26.67% TOTAL SYSTEM % 28.75% 1504 (SUB) 1502 (SUB) AMPS A AMPS B AMPS C AVE AMPS AMPS A AMPS B AMPS C AVE AMPS BUS VOLTAGE 14,200 BUS VOLTAGE 14, TOTAL SYSTEM % 32.30% TOTAL SYSTEM % 16.76% POLE 38 CHOCKSETT ROAD POLE 1 PRATTS JUNCTION ROAD AMPS 41-B AMPS 42-C AMPS 43-A AVE AMPS AMPS 41-A AMPS 42-C AMPS 43-B AVE AMPS ,800 13, TOTAL SYSTEM % 4.76% TOTAL SYSTEM % 8.32% POLE 53 PRINCETON ROAD POLE 10 HEYWOOD ROAD AMPS 41-A AMPS 42-C AMPS 43-B AVE AMPS AMPS 41-A AMPS 42-C AMPS 43-B AVE AMPS ,800 13, TOTAL SYSTEM % 5.59% TOTAL SYSTEM % 4.52% POLE 53 BEAMAN ROAD POLE 3-2 LEGATE HILL ROAD AMPS 41-B AMPS 42-C AMPS 43-A AVE AMPS AMPS 41-A AMPS 42-C AMPS 43-B AVE AMPS ,800 13, TOTAL SYSTEM % 5.83% TOTAL SYSTEM % 7.13% POLE 46 WORCESTER ROAD POLE 8 MAPLE STREET AMPS 41-A AMPS 42-C AMPS 43-B AVE AMPS AMPS 41-B AMPS 42-C AMPS 43-A AVE AMPS ,800 13, TOTAL SYSTEM % 13.56% TOTAL SYSTEM % 8.80% POLE 5 WILES ROAD AMPS 41-A AMPS 42-C AMPS 43-B AVE AMPS TOTAL SYSTEM % 13, %

30 DATE 03/02/11 TIME 1:00 PM WEATHER SUNNY TEMP 40 FORMULAS Full Load MW = (((Ave A * V * Sqrt(3))/1000)/1000) TOTAL SYSTEM (MW) 7.1 AMPS A AMPS B AMPS C AMPS A AMPS B AMPS C MW METER 5.5 MW METER 1.6 VAR METER 0.5 VAR METER 0 TRANSMISSION VOLTS TRANSMISSION VOLTS 118 BUS 1 VOLT METER BUS 2 VOLT METER (SUB) 1501 (SUB) AMPS A AMPS B AMPS C AVE AMPS AMPS A AMPS B AMPS C AVE AMPS BUS VOLTAGE 14,200 BUS VOLTAGE 14, TOTAL SYSTEM % 43.65% TOTAL SYSTEM % 9.93% 1504 (SUB) 1502 (SUB) AMPS A AMPS B AMPS C AVE AMPS AMPS A AMPS B AMPS C AVE AMPS BUS VOLTAGE 14,200 BUS VOLTAGE 14, TOTAL SYSTEM % 30.83% TOTAL SYSTEM % 16.17% POLE 38 CHOCKSETT ROAD POLE 1 PRATTS JUNCTION ROAD AMPS 41-B AMPS 42-C AMPS 43-A AVE AMPS AMPS 41-A AMPS 42-C AMPS 43-B AVE AMPS ,800 13, TOTAL SYSTEM % 24.69% TOTAL SYSTEM % 12.23% POLE 53 PRINCETON ROAD POLE 10 HEYWOOD ROAD AMPS 41-A AMPS 42-C AMPS 43-B AVE AMPS AMPS 41-A AMPS 42-C AMPS 43-B AVE AMPS ,800 13, TOTAL SYSTEM % 9.43% TOTAL SYSTEM % 4.04% POLE 53 BEAMAN ROAD POLE 3-2 LEGATE HILL ROAD AMPS 41-B AMPS 42-C AMPS 43-A AVE AMPS AMPS 41-A AMPS 42-C AMPS 43-B AVE AMPS ,800 13, TOTAL SYSTEM % 0.00% TOTAL SYSTEM % 6.96% POLE 46 WORCESTER ROAD POLE 8 MAPLE STREET AMPS 41-A AMPS 42-C AMPS 43-B AVE AMPS AMPS 41-B AMPS 42-C AMPS 43-A AVE AMPS ,800 13, TOTAL SYSTEM % 12.34% TOTAL SYSTEM % 7.74% POLE 5 WILES ROAD AMPS 41-A AMPS 42-C AMPS 43-B AVE AMPS TOTAL SYSTEM % 13, %

31 DATE 04/04/11 TIME 8:30 AM WEATHER OVERCAST TEMP 46 FORMULAS Full Load MW = (((Ave A * V * Sqrt(3))/1000)/1000) TOTAL SYSTEM (MW) 7.5 AMPS A AMPS B AMPS C AMPS A AMPS B AMPS C MW METER 4.5 MW METER 3 VAR METER 0 VAR METER 0.7 TRANSMISSION VOLTS TRANSMISSION VOLTS BUS 1 VOLT METER BUS 2 VOLT METER (SUB) 1501 (SUB) AMPS A AMPS B AMPS C AVE AMPS AMPS A AMPS B AMPS C AVE AMPS BUS VOLTAGE 14,200 BUS VOLTAGE 14, TOTAL SYSTEM % 22.52% TOTAL SYSTEM % 29.51% 1504 (SUB) 1502 (SUB) AMPS A AMPS B AMPS C AVE AMPS AMPS A AMPS B AMPS C AVE AMPS BUS VOLTAGE 14,200 BUS VOLTAGE 14, TOTAL SYSTEM % 34.21% TOTAL SYSTEM % 15.30% POLE 38 CHOCKSETT ROAD POLE 1 PRATTS JUNCTION ROAD AMPS 41-B AMPS 42-C AMPS 43-A AVE AMPS AMPS 41-A AMPS 42-C AMPS 43-B AVE AMPS ,800 13, TOTAL SYSTEM % 4.14% TOTAL SYSTEM % 8.50% POLE 53 PRINCETON ROAD POLE 10 HEYWOOD ROAD AMPS 41-A AMPS 42-C AMPS 43-B AVE AMPS AMPS 41-A AMPS 42-C AMPS 43-B AVE AMPS ,800 13, TOTAL SYSTEM % 4.04% TOTAL SYSTEM % 4.04% POLE 53 BEAMAN ROAD POLE 3-2 LEGATE HILL ROAD AMPS 41-B AMPS 42-C AMPS 43-A AVE AMPS AMPS 41-A AMPS 42-C AMPS 43-B AVE AMPS ,800 13, TOTAL SYSTEM % 6.06% TOTAL SYSTEM % 6.37% POLE 46 WORCESTER ROAD POLE 8 MAPLE STREET AMPS 41-A AMPS 42-C AMPS 43-B AVE AMPS AMPS 41-B AMPS 42-C AMPS 43-A AVE AMPS ,800 13, TOTAL SYSTEM % 11.58% TOTAL SYSTEM % 6.27% POLE 5 WILES ROAD AMPS 41-A AMPS 42-C AMPS 43-B AVE AMPS TOTAL SYSTEM % 13, %

32 DATE 05/04/11 TIME 8:00 AM WEATHER OVERCAST TEMP 58 FORMULAS Full Load MW = (((Ave A * V * Sqrt(3))/1000)/1000) TOTAL SYSTEM (MW) 7 AMPS A AMPS B AMPS C AMPS A AMPS B AMPS C MW METER 4.3 MW METER 2.7 VAR METER -0.2 VAR METER 0.1 TRANSMISSION VOLTS TRANSMISSION VOLTS BUS 1 VOLT METER BUS 2 VOLT METER (SUB) 1501 (SUB) AMPS A AMPS B AMPS C AVE AMPS AMPS A AMPS B AMPS C AVE AMPS BUS VOLTAGE 14,200 BUS VOLTAGE 14, TOTAL SYSTEM % 22.02% TOTAL SYSTEM % 27.17% 1504 (SUB) 1502 (SUB) AMPS A AMPS B AMPS C AVE AMPS AMPS A AMPS B AMPS C AVE AMPS BUS VOLTAGE 14,200 BUS VOLTAGE 14, TOTAL SYSTEM % 37.95% TOTAL SYSTEM % 14.87% POLE 38 CHOCKSETT ROAD POLE 1 PRATTS JUNCTION ROAD AMPS 41-B AMPS 42-C AMPS 43-A AVE AMPS AMPS 41-A AMPS 42-C AMPS 43-B AVE AMPS ,800 13, TOTAL SYSTEM % 3.76% TOTAL SYSTEM % 8.65% POLE 53 PRINCETON ROAD POLE 10 HEYWOOD ROAD AMPS 41-A AMPS 42-C AMPS 43-B AVE AMPS AMPS 41-A AMPS 42-C AMPS 43-B AVE AMPS ,800 13, TOTAL SYSTEM % 4.89% TOTAL SYSTEM % 7.74% POLE 53 BEAMAN ROAD POLE 3-2 LEGATE HILL ROAD AMPS 41-B AMPS 42-C AMPS 43-A AVE AMPS AMPS 41-A AMPS 42-C AMPS 43-B AVE AMPS ,800 13, TOTAL SYSTEM % 5.58% TOTAL SYSTEM % 6.49% POLE 46 WORCESTER ROAD POLE 8 MAPLE STREET AMPS 41-A AMPS 42-C AMPS 43-B AVE AMPS AMPS 41-B AMPS 42-C AMPS 43-A AVE AMPS ,800 13, TOTAL SYSTEM % 11.15% TOTAL SYSTEM % 6.15% POLE 5 WILES ROAD AMPS 41-A AMPS 42-C AMPS 43-B AVE AMPS TOTAL SYSTEM % 13, %

33 DATE 06/03/11 TIME 1:45 PM WEATHER SUNNY TEMP 76 FORMULAS Full Load MW = (((Ave A * V * Sqrt(3))/1000)/1000) TOTAL SYSTEM (MW) 7.7 AMPS A AMPS B AMPS C AMPS A AMPS B AMPS C MW METER 7.7 MW METER 0 VAR METER 1 VAR METER 0 TRANSMISSION VOLTS TRANSMISSION VOLTS BUS 1 VOLT METER BUS 2 VOLT METER (SUB) 1501 (SUB) AMPS A AMPS B AMPS C AVE AMPS AMPS A AMPS B AMPS C AVE AMPS *PICKING UP 1501 LOAD BUS VOLTAGE 14,200 BUS VOLTAGE 14, TOTAL SYSTEM % 49.83% TOTAL SYSTEM % 0.85% 1504 (SUB) 1502 (SUB) AMPS A AMPS B AMPS C AVE AMPS AMPS A AMPS B AMPS C AVE AMPS BUS VOLTAGE 14,200 BUS VOLTAGE 14, TOTAL SYSTEM % 49.61% TOTAL SYSTEM % 1.28% POLE 38 CHOCKSETT ROAD POLE 1 PRATTS JUNCTION ROAD AMPS 41-B AMPS 42-C AMPS 43-A AVE AMPS AMPS 41-A AMPS 42-C AMPS 43-B AVE AMPS ,800 13, TOTAL SYSTEM % 23.80% TOTAL SYSTEM % 17.69% POLE 53 PRINCETON ROAD POLE 10 HEYWOOD ROAD AMPS 41-A AMPS 42-C AMPS 43-B AVE AMPS AMPS 41-A AMPS 42-C AMPS 43-B AVE AMPS ,800 13, TOTAL SYSTEM % 3.72% TOTAL SYSTEM % 6.21% POLE 53 BEAMAN ROAD POLE 3-2 LEGATE HILL ROAD AMPS 41-B AMPS 42-C AMPS 43-A AVE AMPS AMPS 41-A AMPS 42-C AMPS 43-B AVE AMPS ,800 13, TOTAL SYSTEM % 6.62% TOTAL SYSTEM % 7.14% POLE 46 WORCESTER ROAD POLE 8 MAPLE STREET AMPS 41-A AMPS 42-C AMPS 43-B AVE AMPS AMPS 41-B AMPS 42-C AMPS 43-A AVE AMPS ,800 13, TOTAL SYSTEM % 10.04% TOTAL SYSTEM % 5.38% POLE 5 WILES ROAD AMPS 41-A AMPS 42-C AMPS 43-B AVE AMPS TOTAL SYSTEM % 13, %

34 AVE AVE SYSTEM TOTAL(MW): 7.9 WINTER CIRCUIT RECLOSER VOLTAGE LINE PERCENTAGE , % P.3-2 LEGATE 13, % P.1 PRATTS 13, % P.10 HEYWOOD 13, % , % P.5 WILES RD 13, % P.8 MAPLE ST 13, % , % P.38 CHOCKSETT 13, % , % P.53 PRINCETON 13, % P.53 BEAMAN 13, % P.46 WORCESTER 13, % CIRCUIT WINTER AVE % P.3-2 LEGATE 5.24% P.1 PRATTS 6.87% P.10 HEYWOOD 4.88% % P.5 WILES RD 4.00% P.8 MAPLE ST 4.97% % P.38 CHOCKSETT 3.66% % P.53 PRINCETON 3.58% P.53 BEAMAN 5.19% P.46 WORCESTER 10.15%

35 AVE AVE SYSTEM TOTAL(MW): 7.5 SPRING CIRCUIT RECLOSER VOLTAGE LINE PERCENTAGE , % P.3-2 LEGATE 13, % P.1 PRATTS 13, % P.10 HEYWOOD 13, % , % P.5 WILES RD 13, % P.8 MAPLE ST 13, % , % P.38 CHOCKSETT 13, % , % P.53 PRINCETON 13, % P.53 BEAMAN 13, % P.46 WORCESTER 13, % SPRING AVE % P.3-2 LEGATE 5.91% P.1 PRATTS 7.38% P.10 HEYWOOD 4.65% % P.5 WILES RD 5.02% P.8 MAPLE ST 4.15% % P.38 CHOCKSETT 4.58% % P.53 PRINCETON 3.64% P.53 BEAMAN 4.22% P.46 WORCESTER 12.41%

36 AVE 2006, AVE SYSTEM TOTAL(MW): 9.2 SUMMER CIRCUIT RECLOSER VOLTAGE LINE PERCENTAGE , % P.3-2 LEGATE 13, % P.1 PRATTS 13, % P.10 HEYWOOD 13, % , % P.5 WILES RD 13, % P.8 MAPLE ST 13, % , % P.38 CHOCKSETT 13, % , % P.53 PRINCETON 13, % P.53 BEAMAN 13, % P.46 WORCESTER 13, % SUMMER AVE % P.3-2 LEGATE 4.13% P.1 PRATTS 6.12% P.10 HEYWOOD 4.29% % P.5 WILES RD 3.26% P.8 MAPLE ST 4.15% % P.38 CHOCKSETT 4.92% % P.53 PRINCETON 3.15% P.53 BEAMAN 4.13% P.46 WORCESTER 8.36%

37 AVE AVE SYSTEM TOTAL(MW): 8.0 FALL CIRCUIT RECLOSER VOLTAGE LINE PERCENTAGE , % P.3-2 LEGATE 13, % P.1 PRATTS 13, % P.10 HEYWOOD 13, % , % P.5 WILES RD 13, % P.8 MAPLE ST 13, % , % P.38 CHOCKSETT 13, % , % P.53 PRINCETON 13, % P.53 BEAMAN 13, % P.46 WORCESTER 13, % FALL AVE % P.3-2 LEGATE 5.03% P.1 PRATTS 6.70% P.10 HEYWOOD 5.22% % P.5 WILES RD 3.85% P.8 MAPLE ST 4.37% % P.38 CHOCKSETT 3.96% % P.53 PRINCETON 2.90% P.53 BEAMAN 4.60% P.46 WORCESTER 9.48%

38 SYSTEM TOTAL(MW): SYSTEM TOTAL(MW): 8.1 WINTER DECEMBER SUMMER JUNE CIRCUIT RECLOSER VOLTAGE LINE PERCENTAGE CIRCUIT RECLOSER VOLTAGE LINE PERCENTAGE , % , % P.3-2 LEGATE 13, % P.3-2 LEGATE 13, % P.1 PRATTS 13, % P.1 PRATTS 13, % P.10 HEYWOOD 13, % P.10 HEYWOOD 13, % , % , % P.5 WILES RD 13, % P.5 WILES RD 13, % P.8 MAPLE ST 13, % P.8 MAPLE ST 13, % , % , % P.38 CHOCKSETT 13, % P.38 CHOCKSETT 13, % , % , % P.53 PRINCETON 13, % P.53 PRINCETON 13, % P.53 BEAMAN 13, % P.53 BEAMAN 13, % P.46 WORCESTER 13, % P.46 WORCESTER 13, % SYSTEM TOTAL(MW): , SYSTEM TOTAL(MW): 9.5 WINTER JANUARY SUMMER JULY CIRCUIT RECLOSER VOLTAGE LINE PERCENTAGE CIRCUIT RECLOSER VOLTAGE LINE PERCENTAGE , % , % P.3-2 LEGATE 13, % P.3-2 LEGATE 13, % P.1 PRATTS 13, % P.1 PRATTS 13, % P.10 HEYWOOD 13, % P.10 HEYWOOD 13, % , % , % P.5 WILES RD 13, % P.5 WILES RD 13, % P.8 MAPLE ST 13, % P.8 MAPLE ST 13, % , % , % P.38 CHOCKSETT 13, % P.38 CHOCKSETT 13, % , % , % P.53 PRINCETON 13, % P.53 PRINCETON 13, % P.53 BEAMAN 13, % P.53 BEAMAN 13, % P.46 WORCESTER 13, % P.46 WORCESTER 13, % SYSTEM TOTAL(MW): &2011 SYSTEM TOTAL(MW): 10.3 WINTER FEBRUARY SUMMER AUGUST CIRCUIT RECLOSER VOLTAGE LINE PERCENTAGE CIRCUIT RECLOSER VOLTAGE LINE PERCENTAGE , % , % P.3-2 LEGATE 13, % P.3-2 LEGATE 13, % P.1 PRATTS 13, % P.1 PRATTS 13, % P.10 HEYWOOD 13, % P.10 HEYWOOD 13, % , % , % P.5 WILES RD 13, % P.5 WILES RD 13, % P.8 MAPLE ST 13, % P.8 MAPLE ST 13, % , % , % P.38 CHOCKSETT 13, % P.38 CHOCKSETT 13, % , % , % P.53 PRINCETON 13, % P.53 PRINCETON 13, % P.53 BEAMAN 13, % P.53 BEAMAN 13, % P.46 WORCESTER 13, % P.46 WORCESTER 13, % SYSTEM TOTAL(MW): SYSTEM TOTAL(MW): 8.6 SPRING MARCH FALL SEPTEMBER CIRCUIT RECLOSER VOLTAGE LINE PERCENTAGE CIRCUIT RECLOSER VOLTAGE LINE PERCENTAGE , % , % P.3-2 LEGATE 13, % P.3-2 LEGATE 13, % P.1 PRATTS 13, % P.1 PRATTS 13, % P.10 HEYWOOD 13, % P.10 HEYWOOD 13, % , % , % P.5 WILES RD 13, % P.5 WILES RD 13, % P.8 MAPLE ST 13, % P.8 MAPLE ST 13, % , % , % P.38 CHOCKSETT 13, % P.38 CHOCKSETT 13, % , % , % P.53 PRINCETON 13, % P.53 PRINCETON 13, % P.53 BEAMAN 13, % P.53 BEAMAN 13, % P.46 WORCESTER 13, % P.46 WORCESTER 13, % SYSTEM TOTAL(MW): SYSTEM TOTAL(MW): 7.5 SPRING APRIL FALL OCTOBER CIRCUIT RECLOSER VOLTAGE LINE PERCENTAGE CIRCUIT RECLOSER VOLTAGE LINE PERCENTAGE , % , % P.3-2 LEGATE 13, % P.3-2 LEGATE 13, % P.1 PRATTS 13, % P.1 PRATTS 13, % P.10 HEYWOOD 13, % P.10 HEYWOOD 13, % , % , % P.5 WILES RD 13, % P.5 WILES RD 13, % P.8 MAPLE ST 13, % P.8 MAPLE ST 13, % , % , % P.38 CHOCKSETT 13, % P.38 CHOCKSETT 13, % , % , % P.53 PRINCETON 13, % P.53 PRINCETON 13, % P.53 BEAMAN 13, % P.53 BEAMAN 13, % P.46 WORCESTER 13, % P.46 WORCESTER 13, % SYSTEM TOTAL(MW): SYSTEM TOTAL(MW): 7.7 SPRING MAY FALL NOVEMBER CIRCUIT RECLOSER VOLTAGE LINE PERCENTAGE CIRCUIT RECLOSER VOLTAGE LINE PERCENTAGE , % , % P.3-2 LEGATE 13, % P.3-2 LEGATE 13, % P.1 PRATTS 13, % P.1 PRATTS 13, % P.10 HEYWOOD 13, % P.10 HEYWOOD 13, % , % , % P.5 WILES RD 13, % P.5 WILES RD 13, % P.8 MAPLE ST 13, % P.8 MAPLE ST 13, % , % , % P.38 CHOCKSETT 13, % P.38 CHOCKSETT 13, % , % , % P.53 PRINCETON 13, % P.53 PRINCETON 13, % P.53 BEAMAN 13, % P.53 BEAMAN 13, % P.46 WORCESTER 13, % P.46 WORCESTER 13, %

39 Date: Road: Jewett Rd (Ofr of Rte 62) POLE PETITION Proposed poles: 4 & 5 bpo~ ~ ~ roposed POLES & ANCHORS. \\~ I \...,..: if---- SPANS AT 150FT \ \ \ \ \ POLE 4- b. ~ -( """......,... '" I JEWETTRD

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