Microgrids and the Macrogrid

Presentation to the

California Public Utilities Commission20 February 2001

by

Abbas Akhil, Chris Marnay, & Bob LasseterSandia National Laboratory, Berkeley Lab, and University of Wisconsin, Madison

Consortium for Electric Reliability Technology Solutions

Other Members of CERTS Distributed Energy Resources Group:

Bob Yinger - SCE, Jeff Dagle - PNNL, John Kueck - ORNL

Outline

INTRODUCTION TO CERTS - Abbas

THE EMERGING MICROGRID PARADIGM - Chris

DER TECHNOLOGY AND THE MICROGRID - Bob

CONCLUSION - Bob

QUESTIONS - all

CERTS Mission Statement

“To research, develop, and disseminate new methods, tools, and technologies to protect and enhance the reliability of the U.S. electric power system under the emerging competitive electricity market structure”

CERTS Formation

Formed in 1998 as an Industry, DOE Labs and Universities consortium

Research Performers

Core Research Areas

Reliability and Markets

Distributed Energy Resources Integration

Real-TimeGrid Reliability Management

Reliability Technology Issues and Needs Assessment

Addresses recommendations made by Secretary of Energy Advisory Board (SEAB) Task Force on Electric System Reliability

CERTS Road Map

Assess market design and reliability performance

Price transparency and load participation for reliability management

Reliability and Markets

Microgrids

DER integration

Customer reliability and power quality

Distributed Energy Resources Integration

Real-time controls and visualization technologies for VAR management, ancillary services, ACE, load forecasting

Reliability performance measures, tracking and monitoring

Real-Time Grid Reliability Management

Reliability monitoring and issues

Research road mapping

Technology tracking

Policy issues and research planning

Reliability Technology Issues and Needs Assessment

CERTS Industry Advisory Board

• VIKRAM S. BUDHRAJA - ChairPresidentElectric Power Group

• MICHEHL R. GENTPresidentNorth American Electric Reliability Council

• TERRY M. WINTERChief Executive OfficerCalifornia Independent System Operator

• PHILLIP G. HARRISPresident and CEOPJM Interconnection, L.L.C.

• BRUCE A. RENZformer VP Energy Delivery SupportAmerican Electric PowerChair, AEIC Electric Reliability CommitteeEPRI Research Advisory Council

• CHARLES B. CURTISExecutive Vice PresidentUnited Nations Foundation

• RICK A. BOWENExecutive Vice PresidentDynegy

• PAUL BARBERSr. Vice President, Transmission & Engrg.Citizens Power

• DALE T. BRADSHAWSenior Mgr., Power Delivery TechnologyTennessee Valley Authority

• JOHN D. WILEYProvost & Vice Chancellor, AcademicUniversity of Wisconsin

Funding

DOE CERTS Relationship

Distributed EnergyResources

CERTSSponsorship/Funding

Transmission ReliabilityProgram

Other Programs

Office of PowerTechnologies

The DOE DER Program Goals

Near Term (Year 2005): Develop the “next generation” distributed energy

technologies and address institutional/regulatory barriers

Mid Term (Year 2010): Reduce the costs and emissions and increase

efficiency and reliability of distributed technologies to achieve 20% of new capacity additions

Long Term (Year 2020): Make the nation’s electric system the cleanest, most

efficient, reliable and affordable in the world by maximizing the use of distributed energy resources

Program Differences

DOE DER Program sets national policy, goals Technology improvements: Advanced microturbines, gas-

fired engines Strong emphasis on combined heat and power Focus on reducing institutional and regulatory barriers

CERTS DER activity focuses on DG systems issues

Examines DG from transmission reliability perspective Effects of large penetration of DG into the grid:

Control, protection, role in the grid and competitive market

Framing the Issues

DOE DER Program goal: 20% of new generation capacity additions through

distributed generation by year 2010 26.5 GW of DG If “small” DG ( <100 kW) captures 25% of the

26.5 GW goal, then -

100,000 small DG sources could populate the grid…

Meeting Future Electricity Demand according to the Annual Energy Outlook 2001

to 2020 U.S. electricity demand: will grow at only 1.8%/a (GDP at 3.0) but with retirements, that’s almost 400 GW new capacity that’s 92% natural gas fired, tripling NG use for power

roughly equivalent to 1000 new generating stations plus associated transmission and distribution (an investment of ~ $400 billion)

NG prices increase at only 2%/a real

electricity prices fall at 0.5%/a real

share of electricity passing through high voltage grid unchanged

Limits of Current Power System other restrictions on power system expansion

siting, environmental, right-of-way, etc.

efficiency limits (carbon, CHP/cogeneration, & losses)

centralized power system planning

heterogeneous power quality requirements extreme customer requirements high cost of reliability?

volatile bulk power markets

economic drive to operate power system closer to limits

can the traditional power system deliver digital power?

Customer Driven Development

apply emerging technologies to self generate

meet heterogeneous customer requirements locally control reliability and quality close to end-use optimize meshed grid reliability for bulk transactions

operate connected or disconnected to the grid

make decisions about power system expansion & operation

group sources and loads

optimize over compatible electrical and heat requirements

power system of relatively weakly interconnected microgrids?

A microgrid is ... designed, built, and controlled by “customers”

based on internal requirements subject to the technical, economic, and regulatory

opportunities and constraints faced. a cluster of small (e.g. < 500 kW) sources,

storage systems, and loads which presents itself to the grid as a legitimate entity, i.e. as a good citizen

interconnected with the familiar wider power system, or macrogrid, but can island from it

Customer DER Adoption

goal is to anticipate the microgrid technical problems that must be solved

forecast the attractive technologies and configurations

customer decision is akin to utility planning

local constraints on development critical - GIS

microgrids unlikely to disconnect entirely

DER adoption can/will be shaped by tariff policy

DER Adoption by a Typical Office Building

on-site

installed ca

pacity

economic environment scenarios

Key DG Technology

Substation DG1-10 MW: 2.2 kV & up

Combustion Turbines Reciprocating Engines Fuel Cells Hybrids

“Appliance like” DG~ 100 kW: 120 - 480 V

Microturbine Photovoltaic

Automotive Fuel Cell

Generation Efficiencies

10kW 100kW 1 MW 10MW 100MW 1000MW 20%

30%

40%

50%

60%

70%

Micro Turbine

CHP

Fuel Cell

WithCHP

HybridFuel cell

ReciprocatingEngines

CCTGCCTG

GasTurbineGasTurbine

Oldsteam

1 MW

Reciprocating Gen Sets

Diesel gen sets generally will be your best choice when:• Low installed cost ($/kW)..• Gas fuel is unavailable or expensive.

Gas gen sets generally will be your best choice when:• Air emissions regulations are a concern.• A reliable gas supply is available and affordable.

Caterpillar’s Gen Sets

In the last 60 days, Caterpillar installed 200MW of rental power throughout the West Coast U.S.

During 2000, they sold nearly 20 gigawatts --

Hybrid Fuel Cells/Microturbine

Commercial Scale Plan

Demonstration

DOE

Technology Program

250kW

1.3MW

2.5MW

Electricity Efficient ( >70%)

The New Paradigm

Distributed generation. Small-scale power systems, installed on multiple commercial and industrial customers' sites, can function as a "virtual power plant" under utility control.

Utilities can dispatch these distributed systems to enhance local grid stability, meet peak demands, capitalize on favorable market prices, and more.

Application of Distributed Generation: New Paradigm

GENERATOR TYPE

Combustion Turbines Fuel Cells Reciprocating Engines Hybrids

KEY ISSUES

Ratings: > 1MW Utility Voltages: 2.2 - 66 kV Dispatchable: Can Participate in Markets

Key DG Technology

Substation DG1-10 MW: 2.2 kV & up

Combustion Turbines Reciprocating Engines Fuel Cells Hybrids

“Appliance like” DG~ 100 kW: 120 - 480 V

Microturbine Photovoltaic

Automotive Fuel Cell

30-75 kW Micro turbine30-75 kW Micro turbine

Installed at $700/kW (target is $350/kW)

Efficiency 30%

Air foil bearings Operation speed

60,000-100,000 RPMs

Microturbine Basics

Power electronics

GeneratorGenerator Air

CompressorCompressor

TurbineTurbine

RecuperatorRecuperator

3 Phase ~ 480V AC3 Phase ~ 480V AC

HotHot AirAir

200kW Phosphoric Acid Fuel Cell

The power plant in Santa Clara is rated at 1.8 MW AC net

It contains more than 4,000 cells

$2000-3000/kW

Fuel Cell System

CO2

lb/kWh

Microturbine

C Turbine

PEM Fuel Cells

Hybrid FC/MT

Roof top PV

DualFuel Engine

On Site Generation

NOx

.00115

.00124

.000015

~.0005

.00

.010

CO2

1.188

1.145

0.95

~0.5

.00

1.20

“Air Pollution Emission Impacts Associated with Economic Market Potential of DG in California, June 2000

Key Factors Impacting Application of Small Distributed Generation

GENERATOR TYPE

(appliance like)

MicroturbineAutomotive Fuel CellPhotovoltaic

KEY ISSUES

Uses Power Electronics Ratings: small ~ 100kW Customer Voltages: 120 - 480 V Dispatchable: Very Complex Difficult to Participate in Markets

due to small size Connection Cost: High

Achieving the 100,000 units

Rethink the paradigm: System approach to DER Enable small-size DER to be a citizen of the

grid Promote multiple unit installations Enable appliance type plug-and-play

functionality Enable market participation

MicroGrid concept assumes a cluster of loads, micro-sources and storage operating as a single system to:

Presented to the grid as a single controllable unit (impacts system reliability; fits new paradigm)

Meets customers needs (such as local reliability or power quality)

MicroGrid ParadigmMicroGrid Paradigm

Utility

Loads, micro-sources & storage

Local voltage control UPS functions Local redundancy Digital power Loss reduction Use of waste heat

Customer

13.8 kV

5

8

M8

M5

Dispatchable load Responds to real-time pricing Simple protection

MicroGrid ParadigmMicroGrid Paradigm

Islanded Factory: Micro Grid

Non-critical Loads

Critical Loads

480V480V

13.8 kV

16

8

22

11

Frequency Droop

P

o

min

1

P22

P16

P11 P8

Island Operation

Transfer to Island

Conclusion: 100,000 units

Key: The MicroGrid (Key: The MicroGrid (An aggregation of micro-sources, loads and storage) Presents itself as a single operating entity to the

grid Customer centered; Key “value added” point Can participate in markets (load management) Recognizes combined heat and power applications No centralized fast control Visualizes an appliance model: “Plug & Play”

model