Solar Interconnection Case StudiesDaniel Kovar – Assistant EngineerEvan Kearney – Jr Engineer

Central Hudson - Distribution Planning

Customers Served

~300,000 Electric

~79,000 Natural Gas

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2010 2011 2012 2013 2014 2015 2016 2017 2018 2019Projected 14.2New 2.0 1.9 3.3 6.3 10.5 16.5 17.0 9.6 13.5Existing 3.6 5.6 7.5 10.7 17.0 27.5 44.0 61.0 70.6 84.1

Meg

aWat

ts (M

W)

Year

Solar Growth as of 12/31/18

Existing New Projected

Hosting Capacity Map

• Interactive online map• Estimates amount of

DER that can be accommodated per distribution circuit

• New update coming in October 2019

https://www.cenhud.com/dg/dg_hostingcapacity

Hosting Capacity Map Pop-Ups

What Factors Affect Hosting Capacity?

Location Circuit Minimum Load Conductor Size Existing DG

Phasing Voltage DistributionEquipment

Protective Devices

Project 1 – 5MW PV

Upgrade Transformer LTC Control

Adjust transformer primary taps by 2.5%

Install a PCC electronic recloser

Install Reclose Block

Install New Service

Total - $207,753

$/kW = $41.55

Upgrades

Reverse Flow Thru Substation Regulator

Overvoltage at Project Inverters

Monitoring and Control

Risk of Unintentional Islanding

Issues that Arose

Conductor Size 336 ACSRPhasing 3-PhasePeak [Substation/Feeder](kW) 12,600 / 3,350Minimum [Substation/Feeder] (kW) 5,140 / 997Total PV (kW) 5,778Customers 488Voltage (kV) 13.2Miles from Sub 0.35Distance from 3-Phase N/ARegulator Banks 1

System Characteristics

Polyphasing/Reconductoring Needed

Overvoltage/Voltage Fluctuation

Protective Device Coordination

Monitoring and Control

Risk of Unintentional Islanding

Issues that Arose

250’ of Polyphasing/Reconductoring

Interconnect at -99% (Consuming Vars) Power Factor

Install a Switched Capacitor bank

Upgrade Upstream Fuses

Install Electronic Recloser at PCC

Install Reclose Block

Upgrade Hydraulic Recloser to Electronic Recloser

Upgrade Feeder Relay Settings

Install New Service

Total - $360,624

$/kW = $180.31

Upgrades

Project 2 – 2MW PV

Conductor Size [POI/Mainline] 4 CU / 336 ACSRPhasing 1-PhasePeak [Substation/Feeder](kW) 6,206Minimum [Substation/Feeder] (kW) 2,648Total PV (kW) 2,446Customers 2,317Voltage (kV) 13.2Miles from Sub 4.29Distance from 3-Phase 250’Regulator Banks 1

System Characteristics

UpgradesUpgradesSystem Characteristics

Dedicated Feeder – 8.51 Miles

Upgrade Substation LTC

Total - $6,537,106

$/kW = $3,268.55

Polyphase 0.51mi 336 ACSR

Interconnect at -95% (Consuming Vars) Power Factor

Install a Switched Capacitor Bank

Reduce System Size to 1.3MW (Tap Movement)

Reduce System Size to 1.056MW (Screen H Flicker)*

Upgrade Regulator and LTC Controls

Reconfigure Feeder Relays

Install PCC Recloser

Install New Service

Total - $502,423

$/kW = $386.34 @ 1.3MW, $475.61 @ 1.056MW

Conductor Size 336 Bare AlPhasing 1-PhasePeak [Substation/Feeder](kW) 22,249/7,773Minimum [Substation/Feeder] (kW) 5,351/2,322Total PV (kW) 4,558Customers 1,821Voltage (kV) 13.2Miles from Sub 8.51Distance from 3-Phase 2700’Regulator Banks 3

Project 3 – 2MW PV

Polyphasing/ Reconductoring Needed

Voltage Fluctuation

Excessive Regulator Tap Movement

Screen H Flicker

Reverse Power Flow Through Regulators

Protective Coordination

Monitoring and Control

Issues that Arose

* Upgrade Not Needed Upon Passing of a Detailed Voltage Flicker Study

$0.00

$200,000.00

$400,000.00

$600,000.00

$800,000.00

$1,000,000.00

$1,200,000.00

$1,400,000.00

$1,600,000.00

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DISTANCE TO SUBSTATION (MI)

Total Cost of Upgrades vs Distance From Substation

< 1MW 1 - 2 MW 2.01 - 4 MW > 4MW

Polyphasing/Reconductoring

Install DTT

Final Remarks

• No single “dependent” factor on upgrade costs.• Central Hudson’s Hosting Capacity Map can assist in finding higher

quality PV locations which can potentially result in minimal upgrades.• Higher costs expected in northern territory due to DTT requirement.

Thank You