Date post: | 16-Feb-2017 |
Category: |
Science |
Upload: | sandia-national-laboratories-energy-climate-renewables |
View: | 81 times |
Download: | 3 times |
Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for
the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-AC04-94AL85000.
Photos placed in horizontal position with even amount of white space
between photos and header
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