Interconnection Issues

PEAC Workshop on DRfor TVA Distributors

September 10, 2002Knoxville, TN

Presented by E.J. HontonResource Dynamics Corporation

DR Interconnection Issues: Standards, Technologies and Impacts on

the Business Deal

8605 Westwood Center DriveVienna, Virginia 22182

541-462-3118 | [email protected]©Copyright 2002 Resource Dynamics Corporation

PEAC’s Workshop on DR for TVA DistributorsKnoxville, TNSeptember 10, 20022 ©Copyright 2002 Resource Dynamics Corporation

Outline

DR marketDR interconnection systems

– interconnection codes and standards– interconnection schematics– interconnection capabilities and products

Interconnection costs and RD&D needs– key solution: a Universal Interconnection Technology– evolving interconnection systems

What to expect, conclusions


What are Distributed Resources (DR)?

Small power generating units and storage devices close toload, under 50 MW, most of output used by host facilityIncludes:

– Combined Heat and Power (CHP)– backup power– niche applications such as premium power, peak shaving, and

green power


What’s the DRMarket Opportunity?

Facilities use DR to generate power on-site in lieu of gridpurchasesCutting energy costs is a primary motivation, but boostingreliability and quality of power is also a driverCurrently, U.S. manufacturers ship over $3 billion annually inDR worldwide, mostly diesel gensets for backup powerRough market estimates based on emergence of improvedDR units call for $5-10 billion annually in U.S. markets alone(equipment and installation)Service market could be substantial at $1-2 billion annually


U.S. DR Interconnection SystemsMarket is Potentially Great in Size

Engines and Combustion Turbines > 100 kW in size– engines (184,000 units; 87,000 MW)– turbines (3,000 units; 58,000 MW)

Microturbines < 100 kW in size for premium power,peak shaving, backup, power export

– 1,200 units; 40 MWFuel cell systems used for prime power

– 200 units; 40 MW

It is important to not ignore options for interconnectingthe many existing small emergency generators


How to AchieveMarket Potential

Emerging technologies must mature and provenoptions need improvementGrid needs to be DR ready

– interconnection technology issues need resolution– EPS/DR interactions must be encouraged

backup powersales to grid/net meteringT&D system deferral value

Market should value non-energy benefits of DR

Cogenerating DR > 1 MW

0

20

40

60

80

100

120

1950 1960 1970 1980 1990 2000

Year Placed in Service

Trill

ion

Btu

Thermal Output Electric Generation


FERC Advanced Noticeof Proposed Rulemaking

Standardization of small generator interconnection agreements andprocedures

– issued August 16, 2002; comments until November 4– applicable to all public utilities that own, operate or control transmission

facilities under the Federal Power Act; or operate in a FERC regulatedmarket

“Simplified procedures and agreements for quick, inexpensive andsimple interconnection” for < 2 MW DR

– based on Texas and PJM models– if meet P1547 and size of circuit rules, then “presumption of approval of

the interconnection without additional testing, fees, or otherrequirements”

Expedited interconnection rules and procedures for 2-20 MW DR

www.ferc.fed.us/electric/gen_inter/small_gen/RM02-12-000.pdf


The Interconnection System

The interconnection systemperforms the functions necessary tomaintain the safety, power quality,and reliability of connected EPSsand DRsSystem complexity depends on thelevel of interaction requiredbetween the DR and the EPS


Why Interconnect?

The users wants the ability to use both the DR and grid,sometimes simultaneouslyUtilities may want the ability to remotely dispatch acustomer’s DR unit - the power export optionUser needs grid for backup, standby


Interconnection is Not aSimple Issue: Utility Concerns

Electric power distribution systems designed for one-way operationPersonnel safety and grid stability are dominantconcernsUtilities reluctant to rely on unfamiliar, customer-supplied protective relaying schemesIntegrated interconnection “packages” not generallyaccepted and known


Interconnection is Not aSimple Issue: Customer Concerns

Utility interconnection costs can be a “deal breaker”for smaller-sized projectsSome requirements not understood by customer, andmay appear unreasonableManufacturer, customer and utility DR activities arefrequently not coordinatedInterconnection requirements are far from standard


DR

DR

DR

DR

DR

DR Can Interconnect in Several Places

Requiring Dispatch and ControlEquipment at Varying Voltages

Complexity also varies by whether a single ormultiple gensets are being interconnected

PEAC’s Workshop on DR for TVA DistributorsKnoxville, TNSeptember 10, 2002

©Copyright 2002 Resource Dynamics Corporation


Many DR Sizes are Being Interconnected

CA Interconnection Requests Nov 2000 - May 2002

010203040506070

< 100 k

W10

0 - 20

0 kW

200 -

400 k

W40

0 - 1,

000 k

W1 -

2 MW

2 - 3.

5 MW

3.5 - 5

MW

5 - 7.

5 MW

7.5 - 1

0 MW

> 10 M

WNu

mbe

r of G

ense

ts


The Interconnection System- Why is it Important?

Understanding the interconnection "black box" marketis important to understanding the future role of andbarriers to DRThe interconnection package is advancing quickly, withfunctional performance available today that was notpossible even 1 year agoThe convergence of software and hardware isproviding protection relaying and coordination functionsat lower cost and at higher reliability


DR Interconnection TechnologyDevelopment at a Crossroads

Digital, multi-function relays emergingRise of inverter technology opened door to inverter-based protective relayingUtility protection and coordination practices have beenbased on “discrete” relays on the utility side of meterUtility protection engineers are now learning andbecoming familiar with digital circuitryTechnology development is now coupled with electronicinformation age


Interconnection “Black Box”The “Black Box” is often more than one boxThe interconnection “black box” provides acombination of functions including power conversion,performance monitoring, protective relaying, andgenerator control and protection“Seamless” power transfer increases complexity withgreater dependence on sub-cycle transfer capability


DR - EPS Grid Interconnection Options

No Interconnection - Complete Isolated OperationIsolated DR - Automatic Transfer to EPSParallel DR Operation - No Power ExportParallel DR Operation with Power Export


DR Application Benefits Increase WithInterconnection

But individuality of “Black Box”interconnection design, permitting,installation, testing and operationincreases costs

NoInterconnection

Isolated DEROperation With

Automatic TransferTo Area EPS

Parallel OperationTo Area EPS, No

Power Export

Parallel OperationTo Area EPS,

Power Export ToArea EPS

BaseloadCogenerationPeak ShavingEmergency/BackupPremiumRemote


Interconnection Codes and Standards

Three organizations are major players in the DR interconnectioncodes and standards arena

– Institute of Electrical and Electronics Engineers (IEEE)– National Fire Protection Association/NEC (NFPA)– Underwriters Laboratories (UL)

Others also issue standards and regulations– International Electrotechnical Commission (IEC)– American National Standards Institute (ANSI)– American Society of Mechanical Engineers (ASME)– American Gas Association (AGA)– Gas Technology Institute (GTI)– National Electrical Manufacturers Association (NEMA)– Electrical Generating Systems Association (EGSA)– Federal, State and Local Governments


Coverage of Standards

Codes and standards set requirements for DRinterconnection equipment manufacture, installation,and operationCodes and standards primarily address reliability,safety and power quality issuesMost standards apply to “components”Limited coverage of interconnection systems

– IEEE P1547– UL 1741

Certification for grid interconnection is a huge gap

BODY OF STANDARDSP1547 Standard for Interconnecting Distributed Resources with Electric Power Systems.

P1589 Standard forConformance TestProcedures forEquipmentInterconnectingDistributed Resourceswith Electric PowerSystem(Lab Certification)

P1608Application Guidefor IEEE 1547Standard forInterconnecting DRwith EPSs (Tipsand Tricks)

Guide for NetworkInterconnection

Guide for Grid/DRImpactsDetermination

Guide forIslanding &Anti-Islanding

DR Specifications andPerformance

InterconnectionSystem

CertificationGuide

P1614Guide forMonitoring, InformationExchangeand Control of DRInterconnected withEPSs.(Communications)


Generic Interconnection System

DER(prime movers,

generators, storage)

DER Electric

Generator

Power

Conversion

Local EPS

Protective

Relaying

Area EPS

Protective

Relaying

Interconnection System

TransferSwitch or

ParallelingSwitchgear

AC

Loads

Area Electric

Power System

(Grid)

Power

Distribution

Power Flow

Communication

Point of Common Coupling

Meter

DG Monitoring

and Metering

Dispatch

and ControlDG Control

DC

Loads


Differentiating InterconnectionSystems

Does the system use an inverter?Does the system have a parallel connection to the EPS?Can the system export power to the EPS?Is the system remotely dispatchable?Application type (and owner/operator), e.g., baseload,cogeneration, emergency/backup, premium, remote?


Today’s Most Common InterconnectionBlack Box

DER Prime

Mover

DER Electric

Generator

Area EPS

Protective

RelayingInterc onnection System

AutomaticTransferSwitc h

AC

Loads

Area Electric

Powe r Syste m

Powe r

Distribution

Power Flow

C omm unication

Point o f C om mon C oupling

Meter

DER Control

DC

Loads

Reciprocating Engine/Combustion Turbine Used for Emergency/Backup


Alternative Configurations RequireDifferent Black Box Components

DER Prime

Mover

DER Electric

Generator

Powe r

Conversion

Local EPS

Protective

Rela ying

Area EPS

Protective

Relaying

Interc onnection System

TransferSwitch or

Para llelingSwitchgear

AC

Loads

Area Electric

Powe r Syste m

UPS with

StoragePowe r

Distribution

Powe r Flow

Communica tion

Point o f Com mon Coupling

Meter

DER Control

DC

Loads

Reciprocating Engine/Combustion Turbine Used for Premium Power


Microturbine Used for Prime Power, as aPeaking Unit, For Backup or Power Export

DER Prime

Mover

DER Electric

Generator

Interc onnection System

AC

Loads

Area Electric

Powe r Syste m

Powe r

Distribution

Power Flow

Point o f Com mon Coupling

Meter

DC

Loads

Powe r Conversion that Includes: Synchronization for Paralleling Oper ation Local EPS and Area EPS Protective Relaying DER Control and Monitoring Dispatch and Control


Small PV System with Net Metering

DER Prime

Mover

Power Conversion that Includes: Undervoltage /Ove rvoltage Under Frequency/O verfrequency Overcurrent Synchronization Ground Fault Overvoltage Active-Anti Island Function

Interc onnection Syste m

AC

Loads

Power

D istribution

Po int of Com mo n Cou pling

Net Meter

DC

Loads

Power Flow

Area Electric

Power System


Interconnection Capabilities

• Exciter control system for generators• Synchronizer to transfer power DR EPS• Automatic transfer switch control• Import/export control• Protective relay functions

− over/under frequency and voltage− directional real and reactive power flow− phase-to-phase current balance

• Metering or net metering• Remote communications capabilities

These may or maynot be modularcomponents


Genset ControlSystem Components

1. Genset controls, e.g. governor control and voltage regulation2. Man-machine interface at the genset, control room near the

genset, and remote sites3. Communications interface to the controllers, hardware and

operating system software for the control system4. Power management software that manages the gensets in

relation to the grid as well as the protective relay functions5. Monitoring and metering module

A key issue is whether to include interconnectioncapabilities within the genset controls or in the black box


Categories of InterconnectionEquipment Product Offerings

1. Transfer switches2. Paralleling switchgear3. Dispatch, communication, and control4. DR controls5. Power conversion6. Metering and monitoring7. Relays and protective relaying

Most genset control system components could be andsometimes are built into an interconnection system


Many Companies Make InterconnectionSystem Components

• Transfer Switches: ABB, ASCO, Capstone, Caterpillar,Cummins, Cutler-Hammer, Cyberex, Danaher, Generac, GEZenith, Inverpower, Kohler, L-3 Communications, PDI, S&C,Siemens, Silicon Power, Thomson Technology

• Paralleling Switchgear: ABB, Alpha Power, Cummins, Cutler-Hammer, Encorp, Enercon, Generac, GE Zenith, IntegratedPower, Kohler,Mitsubishi, PACS Industries, Siemens, Square D,Thomson Technology, Toshiba, ZTR Control

• Dispatch, Communication and Control: ABB, AeroVironment,Alpha Power, ASCO, Capstone, Caterpillar, Encorp, Enercon,GE Zenith, Hydrogenics, Invensys, Mitsubishi, PowerMeasurement, Siemens, Silicon Energy, Toshiba


Companies (continued)

• DR Controls: ABB, AeroVironment, Alpha Power,ASCO, Basler, Beckwith, Capstone, Caterpillar, Cummins,Detroit Diesel, Encorp, Enercon, Generac, Hatch & Kirk,Ingersoll-Rand, Integrated Power Solutions, Invensys,Kohler, Petrotech, Solectria, Sonat Power Systems,Thomson Technology, Toshiba, Waukesha, Woodward,ZTR Control Systems

• Power Conversion (including Inverters): ABB,Advanced Energy, Cherokee Electronics, Exceltech, GEZenith, Inverpower, L-3 Communications, Magnetek,Mitsubishi, Nova Electric, Philtek, S&C, Siemens, SMAAmerica, Solectria, Solidstate Controls, Toshiba, TumblerTechnologies, Vanner, Xantrex, Woodward


Companies (continued)

• Metering and Monitoring: ABB, Advanced Energy, AlphaPower, Ametek Power Instruments, ASCO, Basler, Beckwith,Capstone, Caterpillar, Cutler-Hammer, Electro Industries,Encorp, Enetics, Generac, GE Zenith, Heliotronics, Hydrogenics,Invensys, L-3 Communications, Liebert, Measurlogic,Omnimetrix, PDI, Power Measurement, Reliable Power Meters,Siemens, Simpson, Square D, Thermo Westronics, Toshiba,Vanner, Woodward, ZTR Control

• Relays and Protective Relaying: ABB, Basler, Beckwith,Capstone, Cutler-Hammer, Encorp, GE Zenith, SchweitzerEngineering Labs, Siemens, Square D, Toshiba, ZTR ControlAll companies are not designing their architecture to the samestandards; not all equipment can work with other components


Protection Equipment• 81 O/U• 3PH 59• 3PH 27• 47• 59N• 51G• 50/51• 50/51G

Power MonitoringEquipment• 3PH• All powerparameters incl kwHkVA hr etc andharmonics• Modbus Output• Typically notRevenue grade, butmight be

Typical “Mid Size” Interconnection System(4160V, 5.6MW on 35kV radial feeder)

Example GE Zenith console


DR Interconnection Standardization

Current approach– various engineering designs– collection of individual components

EPS practices dominate todayPromised benefits from

– standardization– integration– interoperability


Typical DR Siting Costs

Siting costs vary greatly by project size, location, complexityand the role of outside parties

“Individual” site specific interconnection packages increasecost of equipment as well

Typical Costs per kWCost Category DR Units <500 kW DR Units >500 kWGenset capital cost $600-1,500 $400-1,200Engineering, permitting, installation $200-700 $150-600Interconnection and testing $75-300 $25-200


Static Transfer Switch(Digital, Inverter Based) Pricing, $/kW

$0

$100

$200

$300

$400

$500

$600

$700

$800

$900

0 50 100 150 200 250

kW

$/kW

Note: Price includes a power distribution unit (PDU)


Automatic Transfer Switch Pricing, $/kW

$0

$10

$20

$30

$40

$50

$60

$70

$80

0 50 100 150 200 250 300

kW

$/ k

W

A key issue is having flexibility to scale to different power levels


Manual Transfer Switch Pricing, $/kW

$0

$50

$100

$150

$200

$250

0 10 20 30 40 50 60

kW

$/kw

Price does not vary appreciably with kW rating


Inverter Pricing, $/kW

Inverters often work with smaller DR generators (PV, fuel cells)

$0

$200

$400

$600

$800

$1,000

$1,200

$1,400

$1,600

$1,800

$2,000

0 1 2 3 4 5 6

kW

$/kW


U.S. Interconnected Systems

Duration of Interconnection

Continuous

Type of Interconnection System

Momentary(<100ms)

Extended(30 min - 12 hours)

Short(1 min - 5 min)

Closed TransitionStatic

Transfer Switch

SoftloadAutomatic

Transfer Switch

SoftloadParalleling

Switchgear

Peak ShaveParalleling

Switchgear

BaseloadParalleling

Switchgear

Customer Interest

Power Quality

Power Reliability

Power Reliability

Rate Abatement

Power Producer

Thousands of Installations

Hundreds of Installations (>250)

Hundreds of Installations (>250)

Over 100 hundred installations

25 - 50 installations

COST

Num

ber of installations


Cutting Edge TechnologyDevelopments are Needed

Successful integration of all DR technologies into EPSStandards and market requirements must be achievable bythe technologyIncreasingly need seamless transfer of powerMust build in design flexibility - modularity?Increasingly complex control systems, paralleling switchgear, and transfer switches are needed for a smart systemMuch technology exists, and even as incremental technicalimprovements are made, most RD&D efforts are designed toimprove system economics


Proposed RD&D Efforts

Defining a single communications protocol (“grid to chip”)Transforming the interconnection system into a set of plug-and-playcomponentsTurning the black box into a distributed metering and monitoringstation of a smart EPSDeveloping more flexible, adaptive, cheaper, and reliable controlsystems using digital processors/telemetry to perform enhancedmetering, logging and dispatchUsing interconnection control and monitoring systems to improveDR environmental performance, as well as unit predictive andscheduled maintenance


Key Solution: A UniversalInterconnection Technology (UIT)

Defines a standardarchitecture forinterconnection systemfunctionsSupports basic andoptional functions andfeaturesModularity, flexibility

Makes DR installations– cheaper– quicker– more reliable

Provide benefits todistribution companies,e.g. easier testability ofDR


Two Types of Interconnection SystemsAre Evolving

• Traditional non-inverter based pre-engineered systems that allow forsynchronization and paralleloperation with the grid(switchgear)

• Inverter based systems for primemovers with DC or high frequencyAC output (i.e. PV systems andfuel cells)


Traditional Non-InverterBased Switchgear

Pre-engineered structures thatcontain the functions necessaryfor synchronization and paralleloperation with the grid:− operator interface− controls− protective relays− circuit breakers− synchronization

Generally used for DR units withmore traditional AC output

UTILITYINCOMING

PTS OPTIONAL

IPRCT

52U

52G

LOAD

CT

GEN

PTS

GPC

Switchgear Single LineDiagram (Kohler PD-100)


Inverter Based Systems

Designed for use with prime moverswith DC or high frequency AC output(i.e. PV systems, fuel cells, andmicroturbines)In the future, inverter basedinterconnection systems may beapplied to standard reciprocatingengine gensets


Example Inverter Based ModularBuilding Blocks

Utility Line

Load(customer)

Control, Communication, &Metering

Communication I/O

Inverter Module

+ -

DC-DC ConverterModule

Output Interface Module

Control &Communication

Module

EnergySource


Reciprocating EngineInverter-based System

Benefits– higher efficiency, lower emissions at part-load– better power quality

Honda EU3000is (3 kW)– 200 volts at 14-17 Hz– rectified to 12 volts– inverted


Some CurrentlyAvailable Interconnection Systems

Company Unit InverterNon-Inverter

ElectricalSpecification

MM-5000 – Grid-Connected MultiModePower Conversion System

X 5 kVAAdvanced EnergySystems

GC-1000 1kW Grid-ConnectedPhotovoltaic Inverter

X 1 kVA

AstroPower SunChoice Program X 8.5 kVABallard EcoStar Power Converter X Up to 110 kVACummins PowerGeneration

PowerCommand Digital ParallelingEquipment

X Up to 2,500 kVA

Detroit Diesel Spectrum SD-100 X Up to 2,400 kVAEncorp enpower-GPC powered “paralleling

switchgear”X 800-5000 amp

Fire Wind and RainTechnologies, LLC

Power Streak Inverter X 5kVA

Kohler PD-100 Switchgear X Up to 2,500 kVAThomson Technology Distributed Generation Switchgear

System/ GCS 2000-DG SystemX Up to 4,000 amp

Vanner Incorprated RE Series Inverters X 5.6 kVAXantrex Grid Tie Inverters X Up to 125 kVAZTR/Shallbetter DGX Switchgear X Up to 4000 amp


Kohler PD-100 Switchgear

20-2,000 kW 800-4,000 ampsNew units and retrofits1/3 the size of typical switchgearModes of operation

− ATS (closed, open, or soft load)− interruptible rate− peak shaving− export to utility

Uses Encorp controller


Ballard EcostarPower Converter

10 kW - 1 MW size rangeVariety of “prime movers”Modes of operation

– grid mode and stand-alone mode operation– grid mode and stand-alone mode transition– stand-alone mode to grid mode transition– standby generator start/stop, remote wake-up, standby function– multi-unit capability up to 1 MW for grid and stand-alone operation– reliable synchronization to the grid– remote monitoring/controls/dispatch


Business Strategies

T&D upgrade deferralCHP with utility supplying equipment, technical know howPeak shaving by owning or leasing DR at industrial sitePrice incentives to interconnect customer DR (low base rate and high“excessive” use charge) for peak shavingPrice incentives for curtailment programsSmart interconnection system (satellite or internet) that feeds backhealth of the T&D systemInvest limited amounts in multiple DR technologiesCustomer reliability enhancer (no interconnection)Short- and medium-term efficiency and operation gains; long-termtechnology developmentAutomotive tie-ins for hydrogen infrastructure, then fuel cells


What to Expect Next?

Evolving regulations, technologies and market adoption of DRUtilities remain uncertain of impact on their T&D operationsStandardized interconnection may not apply universallyImproved manufacturer interconnection packages - lower costand improved performanceAccelerated activity at state and federal levels regardinginterconnection, with reference to IEEE standard


Conclusions

Both the existing conversion and new technology DR marketsare potentially largeDR interconnection systems exist, but are expensiveInterconnection codes and standards are being developedThe choice of interconnection components and the installationcost depend upon the DR applicationMany manufacturers make products, but not all are modularnor do they all work togetherFurther RD&D is needed to lower costsA modular UIT may be forthcomingDistributors may be able to benefit from DR in several ways


For More Information

E.J. Honton, Director, Resource Dynamics Corporation,2046 NW Flanders, Suite 24, Portland, OR 97209, 541-462-3118, [email protected]

N. Richard Friedman, CEO, Resource DynamicsCorporation, 8605 Westwood Center Drive, Suite 410,Vienna, VA 22182, 703-356-1300 ext. 203,[email protected]

www.rdcnet.com and www.distributed-generation.com

Interconnection Issues

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