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the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-AC04-94AL85000.

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DoD Advanced Microgrid Integration Challenges with Utilities

Based on Army Advanced Microgrid Lessons Learned Study

Mike Hightower Military and Energy Systems Analysis Department

Sandia National Laboratories

Summary of Advanced Microgrid Operations

MICROGRID CIRCAPOINT OF COMMONCOUPLING

INTERCONNECTED GENERATION AND LOAD DISCONNECT

/RECONNECT3

sec

POWER RELIABILITY

POWER SECURITY

ANCILLARY BENEFITS USED

DEMANDSUPPORT

UTILITY BACKFEED

RENEWABLES INTEGRATION

GEN LOAD

1960 Substation 8MW 3MW Man, <60 sec x x x x -

1985 Feeder 4MW 2MW Man, <60 sec x x x - -

2005 Feeder 10MW 3MW Man, <60 sec x x - - -

2005 Feeder 5MW 3MW Auto, <10 sec x x X - -

2012 Feeder 1.5MW 1MW Auto, <10 sec x x X - 25%

2012 Feeder 4MW 2MW Auto, <10 sec x x - - -

2013 Feeder 3MW 1.5MW Auto, <10 sec x x - - 30%

2015 Feeder 5MW 3MW Auto, <10 sec x x x - -

2016 Feeder 20MW 15MW Auto, <10 sec x x x - 40%

2000 Substation 80MW 15MW Man, <90 sec x x - x -

2013 Feeder 1.2MW 1MW Auto, <10 sec x x X - 20%

2014 Feeder 8 MW 5 MW Auto, <10 sec x x - - 20%

1 – Decommissioned2 – Under planning/construction - Ft. Bragg (ESTCP), Ft. Detrick (IMCOM)3 - ~ 60 sec needed for high value ancillary services

Current advanced microgrid operational focus is on energy security and reliability, but not taking full advantage of ancillary use and associated cost benefits.

Energy security Energy safety Energy reliability Energy resiliency Renewables integration Control performance Ancillary benefits Cost effectiveness

Current Advanced Microgrid Operational Performance

ExcellentGoodFair

Focus of Army microgrid improvement recommendations

Positive Advanced Microgrid Operation Observations No major technical implementation

and operation challenges identified No safety issues observed in

transitioning between grid-tied and islanded modes

All control systems support ~10 - 60 second transition to islanded operations, critical circuits on UPS systems, all controls meet cyber security requirements

Renewable energy technologies were utilized and effectively integrated with other generation resources

Advanced microgrids can effectively support base demand/response and utility grid support/ancillary services

Microgrid capabilities have matured significantly in past decade.

Current Advanced Microgrid Operational Challenges Microgrid control challenges

Training of site staff on microgrid control and operation is often insufficient

Because of control complexity, many microgrids are operated less than once a year

Renewable energy integration challenges has limited extensive use Lack of price advantage in some locations Utility push back because of intermittency Inability to partition and balance energy

output – design and contracting reasons Renewables systems often not designed to

match energy infrastructure, site loads, etc. due to different policy drivers

Concern about cost of energy storage and impact on system cost effectiveness

Clear Day Cloudy Day

These challenges are hindering microgrid benefits and utilization.

Current Microgrid Operational Challenges (cont’d) Utility demand response/ancillary

services challenges Only 30% of microgrids were used

regularly for demand response or peak shaving

Lack of metering and microgrid control complexity is limiting ancillary support

Most utilities discourage grid support due to lack of performance data

Cost effectiveness challenges Current microgrid costs are ~ $0.20-

$0.30/kWhr vs. $0.06-$0.16/kWhr for grid power

Designs are often N-2 or N-3 load redundant

Environmental issues often impact selection of generation mix for grid tied operations

Ancillary Service

Value of Service

($ per kWhr)

Required Response (minutes)

Frequency Regulation High 1

Spinning Reserve Medium 1-10

Auto Response Medium 10-20

Manual Response Low 30-60

Non-spinning Reserve Very Low 10

Replacement Reserve Very Low 30

A major opportunity is that advanced microgrid response times are compatible with utility ancillary service needs and more microgrid grid-tied data is now available

Utility (PNM) Advanced Microgrid Operational Data

Advanced Microgrid Observed Best Practices Simple controls and well trained and

experienced operators increased microgrid utilization

Enhanced energy metering at a site consistently increased microgrid use for utility support

All sites have implemented many simple strategies - circuit-level UPS systems, VFDs, etc. – which has minimized large-scale energy storage requirements

Renewable energy systems greater than 1 MW partitioned to support feeders or connected to substations, were more easily integrated and utilized

Microgrids designed to consider longer-term outages and associated changes in critical missions provide greater energy resiliency

These practices need to be propagated across the Army

Recommended Strategies and Policies (Prioritized by potential impact)

Diversity of advanced microgrid design approaches reviewed suggests that design and operation standards are needed Establish design, use, and interoperability protocols Similar approach being pursued by the Tactical Microgrid Standards Consortium

and efforts could be leveraged Will eliminate inappropriate microgrid development

Take a much more proactive approach to encourage utilities to incorporate Army advanced microgrids as part of utility Smart Grid initiatives Get Army leadership involved in utility discussions of microgrid operational

requirements for utility acceptance – leverage and expand EITF efforts Provide data to utilities on Army and other advanced microgrid operational

performance and control strategies compatible with utility needs Establish a conceptual architecture, standard design methodology, and

operational approaches that improve the ability to plan, implement, and integrate advanced microgrids with a local utility