#PittEPIC: Challenges, Opportunities, and Why You’re Needed
David Roop, P.E. Director, Electric Transmission Operations 1
October 19, 2018
Dominion Energy Profile
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October 19, 2018
Dominion Energy Profile
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October 19, 2018
Environmental Leadership Solar Investment • Since 2013, Dominion has invested $2.6 Billion in solar • By 2018, the Company will have invested nearly $3.5 Billion in solar Dominion United States Solar Statistics: • 9 States; 2,813 Megawatts including PPA’s • 15,068 Acres • 7.77 Million Panels • 9,300 Construction Jobs • Various technologies and locations including 4
October 19, 2018
Our diversified Generation fleet exceeds 2,000 megawatts of clean energy in 9 states
Dominion Energy Renewables A Growing Renewable Portfolio Aligned with New Virginia Legislation
Coastal Virginia Offshore Wind Project ‐
Two 6‐MW wind turbines (demonstration project) • •
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Strategic partnership with Ørsted of Denmark Prudency filing with SCC
Full deployment could lead to commercial facility up to 2,000 MW
Solar Portfolio ‐
2,400 MW in 9 states by 2020
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Nationwide Rankings
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•
Dominion Energy 4th
•
Dominion Energy Virginia 8th*
•
Commonwealth of Virginia 10th*
Major Milestones •
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240 MW solar project to serve Facebook Data Center
Virginia Solar Growth Opportunity •
Anticipating 3,000 MW 2018‐2022
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National Trends Current Domestic In-Service Solar
Source: NREL 6
October 19, 2018
National Trends Current and Future Domestic In-Service Solar
Source: NREL 7
October 19, 2018
PV Impact on Generation Interconnect Process Non-Traditional Scenario
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•
Greenfield Projects in Queue • Traditional Projects • Small number of interconnection requests • Low success rate for implementation • PV Projects • High number of interconnection requests • High success rate for implementation
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Construction timelines • Traditional Projects 3-5 years • PV 1-2 years October 19, 2018
Inverter Philosophy Evolution •
Previous Approach • Disconnect during abnormal conditions • •
•
Low/High Voltage Low/High Frequency
Unity Power Factor Operation
•
New Grid Support Functions – Smart Inverters • Low/High Voltage Ride Through • Low/High Frequency Ride Through • Real/Reactive power control • Ramp Rate Control
•
PJM • Starting to work on a voltage ride-trough requirement for Distribution generators.
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October 19, 2018
Dominion Energy Customer Expectations • Environmentally friendly generation • Reliable service • More choice and control of their energy use • Low electric rates • Community support and investment
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October 19, 2018
Dominion Energy Initiatives • Fourth largest supplier of solar energy in United States • Investing in T&D to improve reliability • Developing options so customers can manage their energy use • Researching ways to transform our T&D system to handle renewables without significant layered costs • Energy Share, employee engagement in our communities, environmental stewardship
Example: Energy Math Fuel Type: Capital ($/W) Lifetime Site Example Site Capital ($) Fuel Cost ($, 40yr) Natural Gas $1 1,600MW CC Nuclear $14 1,600MW Solar PV $1.25 75MWe 11
October 19, 2018
$1.6B $23B $100M
$15B
GHG/CO2 Operation Capacity Factor Impacts? & Maint. Dispatchable? Costs Yes
Low & Known
>95% Dispatchable
$3.3B
No
Medium >95% & Known Dispatchable
Free
No
Unknown <30% Unknown Non‐dispatchable
Example: Energy Math Fuel Type: Capital ($/W) Lifetime Site Example Site Capital ($) Fuel Cost ($, 40yr) Natural Gas $1 1,600MW CC Nuclear $14 1,600MW Solar PV $1.25 75MWe 12
October 19, 2018
$1.6B $23B $100M
GHG/CO2 Operation Capacity Factor Impacts? & Maint. Dispatchable? Costs What do we Yes
need to address Low & >95% Dispatchable Known if we focus here?
$3.3B
No
Medium >95% & Known Dispatchable
Free
No
Unknown <30% Unknown Non‐dispatchable
$15B
The Future of Our Industry Increasing use of power electronics: • Inverter-based renewable generation • Flexible AC Transmission equipment on transmission system and • Flexible AC Distribution equipment on distribution system • Increasing use of DC driven products in homes and businesses • Increasing use of HVDC around the world to move and control flow of energy • Increasing use of MVDC to move power into urban centers Challenge: Accommodating this changing world effectively to ensure reasonable cost, reliable service, and rapid restoration of service when events do occur. 13
October 19, 2018
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October 19, 2018
Balancing the Energy Future: Technical Considerations
$$$
Dispatch
Storage
Conventional Generation 15
October 19, 2018
Solar PV
>525MW
<300MW <50MW
Nameplates are nice, life is messy Solar Variability – Need a Grid “Effort” Metric
6:00:15 18
8:05:15 October 19, 2018
10:10:15
12:15:15
14:20:15
16:25:15
18:30:15
Nameplates are nice, life is messy Solar Variability – Need a Grid “Effort” Metric
6:00:15 19
8:05:15 October 19, 2018
10:10:15
12:15:15
14:20:15
16:25:15
18:30:15
Development of D-STATCOM Solutions Partnership with MEPPI on the development of a 500kVAR STATCOM solution for distribution applications.
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October 19, 2018
Balancing the Energy Future: Technical Considerations
Dispatch
Compact Control
Conventional Generation 21
October 19, 2018
$$$
$
Storage
Comms
$$ Wide‐ Area Control
Solar PV
Compact Control • Conventional Generation is compact – that is one can enclose a large bulk generation site within a single contour. This allows for: • • •
AGC Droop Control Voltage Schedule Management …all with a few control parameters
• An equivalent control structure for large scale PV generation across multiple sites will involve strategic investments in: • •
Communications Real-time wide-area control …but communications investments are significant and considerable research is needed in wide-area control
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October 19, 2018
Balancing the Energy Future: Technical Considerations
Dispatch
Compact Compact Control Site
Conventional Generation 23
October 19, 2018
$$$
$
Storage
Comms
$$ Wide‐ Area Control
Solar PV
$ Land
Land Requirements: A Brief Comparison
Brunswick County Power Station Freeman, Va. 1,358 MW 205 Acres (0.15 acres per MW) 24
October 19, 2018
Scott Solar Powhatan, Va. 17 MWe 165 Acres (6‐10 acres per MWe)
Balancing the Energy Future: Technical Considerations
$$$ Storage
Dispatch
Compact Compact Control Site
Inertia
Conventional Generation 25
October 19, 2018
Smart Inverters
$$$
$
Storage
Comms
$$ Wide‐ Area Control
Solar PV
$ Land
Future Scenario Analysis (Possible Deployments): Solar Impact on Dynamic Performance Increasing solar penetration levels > > >
20%
40%
60%
80% Source: NREL
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October 19, 2018
Reduced Inertia and Frequency Response due to Solar Penetration
Source: University of Tennessee Knoxsville
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October 19, 2018
Solar Penetration Increases Inter-area Oscillation Frequency Every 20% PV translates in 0.03 Hz frequency increase
Source: University of Tennessee Knoxsville 28
October 19, 2018
Inertia Inertia can be emulated by inverter-based generation, however, there is a cost: • Inertial response most be “programmed” into smart inverter – i.e., synthetic inertia. • Without spinning mass, energy must be drawn from another source, which means either: • •
Battery energy storage pairing Generation curtailed to allow headroom
• In any case, coordination challenges existing energy sector structures: engineering, operations, design, vendor, utility, site owner, etc…
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October 19, 2018
Pairing Solar and Energy Storage
TX
TX
Bus
Bus
Cap Bank 30
Load October 19, 2018
Solar Farm
Battery
Cap Bank
Load
Solar Farm
Battery
A Spectrum of Possible Battery Applications • • • • • • •
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Energy arbitrage Load leveling Renewable integration Spinning reserve Primary voltage/frequency regulation Investment deferral Blackstart
October 19, 2018
Batteries: Multiple Ways to Store Energy • Lithium-ion chemistry is the leading technology. • However, we need to remember the broad spectrum of battery energy storage technologies. • Longest-running, most proven, highest capacity battery is pumped hydro – Dominion Energy exploring new options in southwest Virginia. 32
October 19, 2018
Li‐ion
All Things Considered…Don’t Forget the Physics
Graph Credit: Mark Mills 33
October 19, 2018
Balancing the Energy Future: Technical Considerations
$$$
Fault Current
Dispatch
Compact Compact Control Site
Storage
Inertia
Conventional Generation 34
October 19, 2018
Smart Inverters
$$$
$
Storage
Comms
$$$ Storage
$$ Wide‐ Area Control
Solar PV
Smart Inverters
$ Land
Group Discussion: Is fault
Talk to me!
current a good thing? Well, it
depends. Basic protection of grid today is tied to characteristics of fault current for the detection, location, and rapid automatic response to system problems.
How do you know youâ&#x20AC;&#x2122;re sick if you donâ&#x20AC;&#x2122;t get a fever? 35
October 19, 2018
System Protection Fault Characteristics - completely different from synchronous generator:
Synchronous Generator
Inverter Based Generator
1.2 times rated current
…mimicking fault response of conventional generation takes energy and programming – doable but not free. 36
October 19, 2018
Balancing the Energy Future: Technical Considerations $ Comms
Fault Current
Dispatch
$$$
Relaying Coord.
Compact Compact Control Site
Storage
Inertia
Conventional Generation 37
October 19, 2018
Smart Inverters
$$$
$
Storage
Comms
$$$ Storage
$$ Wide‐ Area Control
Solar PV
Smart Inverters
$ Land
Balancing the Energy Future: Technical Considerations $ Comms
Fault Current
Dispatch
Relaying Coord.
Mature Models
Compact Compact Control Site
Inertia
Conventional Generation 40
October 19, 2018
$$$ Storage
!!! Industry Action Smart Inverters
$$$
$
Storage
Comms
$$$ Storage
$$ Wide‐ Area Control
Solar PV
Smart Inverters
$ Land
Load and Generation Forecasting • Historically, we have forecasted load and dispatched generation. • In the future, will we forecast generation and match load accordingly? • Load masking is an issue.
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October 19, 2018
Modeling the future gridâ&#x20AC;Ś
Legacy Method
New Method
SCADA Measurements 42
October 19, 2018
Contingency Modeling Evaluating the need for contingency modeling and/or adaptive contingency definitions for modeling behavior such as cloud cover. â&#x20AC;˘ Modeling unit loss â&#x20AC;˘ Modeling unit de-rate during cloud cover
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October 19, 2018
Understanding Voltage Response • Most inverters are operated at unity power factor (no Q output) • Voltage rise (∆ V) is proportional to the PV output (P) times the resistance ∆V≈RP+XQ • Location specific – complex modeling
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October 19, 2018
Voltage Regulation: Example 1 “Two-way traffic on a One-way street.” • Large PV installation near beginning of feeder. • Line Drop Compensation sees lower current so it lowers the bus voltage. • LDC “gets fooled” by PV and permits low voltage near the end of the feeder
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October 19, 2018
Voltage Regulation: Example 2 “Two-way traffic on a One-way street.” • Large PV installation near end of feeder • Line drop compensator sees lower current so it holds lower voltage • Voltage rise occurs in the portion of the feeder nearest the PV • End of regulation zone forced above high voltage limits 46
October 19, 2018
Under-Voltage Ride Through (UVRT) â&#x20AC;˘ How do you model this? â&#x20AC;˘ Once you model it, how do you control and coordinate it?
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October 19, 2018
Under-Frequency Ride Through (UFRT) Ditto!
Industry action neededâ&#x20AC;¦.
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October 19, 2018
Balancing the Energy Future: Technical Considerations Fixed &
$
Repeatable
Comms
Physics Fault Current
Dispatch
Relaying Coord.
Mature Models
Compact Compact Control Site
Inertia
Conventional Generation 49
October 19, 2018
$$$ Storage
!!! Industry Action Smart Inverters
$$$
$
Storage
Comms
!!! Diverse and Emulated
$$$ Storage
$$ Wide‐ Area Control
Solar PV
Smart Inverters
$ Land
Ongoing Efforts
– Continue investigation on impact of large number of PV inverters tripping due to system disturbances or lack of fault tolerance on system voltage stability. • Net active and reactive load post fault would be larger than pre-fault scenario. Fault Induced Delayed Voltage Recovery event in Southern California following a 230kV fault
© 2015 Dominion
10/19/2018
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Southwest US Fire Event Blue Cut Fire • In August 2016, the “Blue Cut” Fire caused multiple 500kV faults • All faults cleared normally • However, several of the faults caused multiple utility-scale PV sites to trip offline due to a perception of frequency outside of bounds • “May Trip” vs. “Must Trip” interpretation of off-nominal parameter capability curves, allowed tripping is not the same as mandated tripping (which can lead to cascading instability – as in this very case) • Approach UFRT and UVRT solutions with rigor 2017 Canyon 2 Fire (Similar issues in October of 2017) 51
October 19, 2018
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October 19, 2018
DC Area Low Voltage Event – April 2015
58 second fault: •Failed lightning arrester •Failure of two separate and redundant protection schemes. •532 MW load lost •1,981 MW generation lost 53
October 19, 2018
Grid disturbances happen, how will renewables respond en masse?
Industry Action in the Right Direction In September, NERC issued three valuable Reliability Guidelines in September 2018. Guidelines address: • Power plant model verification for inverter-based resources • BPS-connected inverter-based resource performance • Interconnection Reliability Operating Limits (IROLs) Work has been done to define limits, conditions, and leading practices, but much practical work remains. 54
October 19, 2018
Balancing the Energy Future: Technical Considerations Fixed & Repeatable
Physics Fault Current
Dispatch
Top‐ Down Design
Relaying Coord.
$ Comms
Mature Models
Compact Compact Control Site
Inertia
Conventional Generation 55
October 19, 2018
$$$ Storage
!!! Industry Action Smart Inverters
$$$
$
Storage
Comms
!!! Diverse and Emulated
$$$ Storage
$$ Wide‐ Area Control
Solar PV
$$ Meshed Grids Smart Inverters
$ Land
Balancing the Energy Future: Technical Considerations Fixed & Repeatable
Physics Fault Current
Dispatch
Top‐ Down Design
$
Industry What keeps all of this in Comms balance? Action
Relaying Coord.
$$$ Power ElectronicsStorage & Power Engineering$$$ Inertia
Mature Models
Compact Compact Control Site
Storage
Conventional Generation 60
October 19, 2018
!!!
You are the fulcrum of this scale!
Smart Inverters
$ Comms
!!! Diverse and Emulated
$$$ Storage
$$ Wide‐ Area Control
Solar PV
$$ Meshed Grids Smart Inverters
$ Land
If we had a blank slate, where would we start?
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October 19, 2018
HVDC? PV. Wind. The future?
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October 19, 2018
Microgrids • Resiliency drivers exist today • Market/economics drivers uncertain (economies of scale) • Where does public preference take us? • Domestic DC? (e.g., low voltage household DC bus) • Vertical relationships between energy and information? Grid + Cloud?
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October 19, 2018
Customer Engagement Who are your customers? As an individual? As a student? As a community? As an engineer? We all have customers!
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October 19, 2018
The Future: We have the challenges, opportunities, and the tools. Lab Capabilities: CHIL, RAS, Blackstart, Training, Testing Lab Benefits: Attracting top talent with the best tools and meaningful challenges
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October 19, 2018
Deploying new technology to address operations - from daily events to extreme contingencies •
• •
FACTS Devices on both the transmission and distribution systems – STATCOMS – SVCs Piloting a Distribution STATCOM to support the impacts of DG Increasing resiliency and operation with Mobile STATCOM
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Transmission STATCOM Mobile Advantages • Allows for Project Construction schedules to have expanded windows for construction by eliminating voltage violations – Eliminates mobilization and demobilization of contract resources – Allows for shorter construction schedules – Provides cost savings to ratepayers and stockholders
• Growing deployment of renewables and retirement of conventional generation in short timeframes creating additional VAR and dynamic stress on electric systems before projects can be implemented to resolve – STATCOM mobile allows opportunity to quickly resolve operating issue while long term solutions are constructed
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50 MVAR Mobile STATCOM 125% Overload 2 Seconds
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Mobile equipment & Mobile substations Connecting to the Grid â&#x20AC;˘ Rapid restoration of service (equipment & design) â&#x20AC;˘ Unusual/emergency system conditions
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50 MVAR Mobile STATCOM at Yorktown
Workforce Development Summer graduate student intern program: • Virginia Tech, UT, Pitt, WSU, VCU, and others • Project Focused, Team Assignments, Executive Report-outs, Industry Publications • A win-win-win for student, university, and industry. 71
October 19, 2018
Thank you!
Scott Solar – 17 MW in Powhatan County, Va.
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October 19, 2018
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Change is under way
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Inverter-based generation is on the rise
•
A direct one-to-one equivalency does not exist
•
Look deeper than nameplate energy
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Collateral physics, not free physics
•
Need to balance the scale - you get what you engineer
•
Now is the time to question the norms
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The future is in your hands
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Remember the economic impact of jobs
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Don’t forget your customers
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Our Industry needs YOU!