Microgrids: A Rare Paradigm Shift in Electricity ... · 11/17/2005 · Environmental Energy Technologies Division Conclusion • expansion of electricity supply is constrained in

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Environmental Energy Technologies Division

Microgrids: A Rare Paradigm Shift in Electricity Generation and Delivery

presentation at

Hachinohe Energy Forum

Hachinohe Grand Hotel, Amori Prefecture, Japan

17 November 2005

by

Chris Marnay

research supported by the U.S. Dept of Energy and the California Energy Commission)

der.lbl.gov - [email protected]

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Outline

1. What are Microgrids?

2. Why do we Need Microgrids?

3. The CERTS Microgrid

4. Distributed Energy Resources Customer Adoption Model (DER-CAM)

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History of U.S. Electricity Sector

phases of centralization

1. isolated developments (pre 1900)

2. consolidation and monopolization (1900-1933)

3. fossilization and total centralization (1933-1980)

phases of decentralization

1. independent investment (avoided cost) (1980-1995)

2. wholesale (and some retail) competition (1995- )

3. decentralization and full competition? (2000- )

(What is the role of microgrids?)

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Microgrid: A Definition

A controlled grouping of energy (including electricity) sources and sinks that is connected to the macrogrid but can function independently of it.

Two Main Benefits to Developers of Microgrids:• improve efficiency by combined heat and power (CHP)• provide heterogeneous power quality and reliability (PQR)

There are other potential societal benefits, e.g.• protect vital public services• offer a place for small-scale renewables

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Fort Bragg, North Carolina

Fort Bragg Army Base, North Carolina

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Fort Bragg Army Base, North Carolina

KEY MICROGRID FEATURE IS

LOCAL CONTROL

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Development ofDenmark’s Power System (1980-2000)

source: Eltra (grid operator of western Denmark)

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2. Why do we need Microgrids?

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Why Do We Need Microgrids?• restrictions on power system expansion• centralized power system planning• volatile bulk power markets• insecure system• multiple infrastructure interdependencies• limited qualities of power

• push efficiency limits (use CHP to lower carbon)• heterogeneous power quality and reliability (PQR)

(deliver gourmet power to demanding end uses)• robust decentralized system• other external benefits (protect vital services)

negatives of the M

acrogridpositives of M

icrogrids

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What Does Power Quality and Reliability Really Cost?

lowest in w

orld today→

U.S. today

→perfection

→

cost of unreliability→

total cost of reliability

→

possible effect of DER

cost of reliability→

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An PQR Pyramid• Loads are often broken

down by time and endusebut not by PQR requirements.

• The most demanding PQR requirements are not met.

• Highly sensitive loads are small and they could be smaller.

• Local supply could tailor PQR to the needs of the enduse.

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3. The CERTS Microgrid

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Consortium for Electric Reliability Technology Solutions (CERTS)

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The CERTS Microgrid is ...

• controlled by “customers” based on internal requirements subject to the technical, economic, and regulatory opportunities and constraints faced.

• designed and operated to jointly provide heat and power and heterogeneous power quality and reliability.

• 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.

• controlled by local intelligent inverter like power electronic devices.

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Example CERTS Microgrid

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CEC SupportedActivity

1999 2000 2002 2003 2006 2010

DOE SupportedActivity

A proven, mature Microgrid approach

allows high penetration of DG sources by

providing a resilient platform for plug and play operation of heat and power sources.

Prior Program Activity

Current Program Activity

CERTS Microgrid Research

2001 2004 2005

Fundamental Microgrid Concept Defined

CEC Microgrid Workshop

Survey of DERTest Facilities

Microgrid Protection Issues Paper

Customer Adoption Model

UWM Droop Control Theory

Microsource ModContract

MicrogridTestbed Operational

Develop mGRID Software

Beta Test mGRID Software

Initial Mtgs. W/CEC to Share Microgrid ConceptsInitial Microgrid Testbed Testing Complete

Jointly Funded Field Demo

Testbed Design/RFP Development

Microturbine Testing by SCE/UCI

Possible Integration of Customerand Power Flow Models

Standard Power Electronics Interface

Future Program Activity

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4. Distributed Energy Resources Customer Adoption Model

(DER-CAM)

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DER-CAM Solves Systemically

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Redlands, California

San Bernardino USPS, Redlands CA

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San Bernardino USPS, Redlands, CA

32,000 m2 single-story facility

equipment runs mostly in evening and night

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Meeting Absorption Chiller and Electric Loads

0

500

1000

1500solarDG

absorption chiller thermal load

$500/kWhigh temp. July

US$150/kW low temp. Jan

elec

tric

pow

er (k

W)

0

500

1000

1500

1 5 9 13 17 21hour

solarDG

ther

mal

pow

er (k

W)

0

500

1000

1500

NG-fired DGpurchase

offset by abs.

0

500

1000

1500

1 5 9 13 17 21hour

offset by abs. chiller

purchased

NG-fired DG

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Carbon Constraint Results• high temp. collectors provide carbon

savings at lower control cost than low temp. collectors

• for low carbon reductions PV is…– more economic than high temp. collectors– competitive with low temp. collectors

• solar thermal is still valuable because of storage which offsets evening cooling loads

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DER Equipment Installation Under Carbon Constraint (130 g/kWh)

low temp. collector high temp. collector

01234567

600 800 1000 1200carbon emissions (t/a)

inst

alle

d ca

paci

ty (M

W)

solar collector PV NG-fired DG

01234567

600 800 1000 1200carbon emissions (t/a)

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Conclusion

• expansion of electricity supply is constrained in may ways

• microgrids are a way to increase efficiency and lower carbon

• by providing heterogeneous power quality needs of a digital society can be met at reasonable cost

• the CERTS microgrid is a specific concept

• DER-CAM solves energy systems endogenously

• DER-CAM results provide - valuable starting point for building analysis - or can be generalized to produce higher level estimates of DER adoption

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Microgrids: A Rare Paradigm Shift in Electricity ... · 11/17/2005 · Environmental Energy Technologies Division Conclusion • expansion of electricity supply is constrained in