Document number
Curacao 2012 Durable Energy Conference Renewable Integration Issues Ron Willoughby – Vice President DNV KEMA Energy and Sustainability United States of America March 31, 2012
Topics Part 1 – T&D System Challenges & Opportunities Part 2 – Effects of Solar on the Distribution System Part 3 – Role of the Smart Grid
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Topics  Part 1 – T&D System Challenges & Opportunities
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The Power System
G + T + D + L 4
Renewables Integration Issues Impact of randomly placement Integration out-pacing grid expansion Dynamic control of real power limits, reactive power levels; i.e., to operate like traditional power plants Lost revenue & cost recovery from net metering Public acceptance (affects policy makers)
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Renewables Integration Issues (cont)
Maintaining reliable system performance Adequacy of T & D lines System protection & control Dispatchable generation Use of energy storage Substation / distribution automation Data acquisition & management Compatibility / speed of communications Cyber security 6
Frequency Correction Using Storage
Source: CIGRE Biennial Session - 2010 7
Studies - Essential Planning Tool V-Control V-Flicker Fault Current Power Flow Protection Frequency
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Analysis Timeline Auto Control Realm
Real Time Ops Realm
Ops Planning & Sched Realm
Replacement Reserves Frequency Response
Harmonics
ISSUES
Regulation
Protection Stability
1 ms
1 cycle
Capacity
1 second
Economics Balancing /Dispatch
1 minute
10 minutes
1 hour
1 day
1 month
1 year
Time Step Increases STUDIES
Statistical Analysis of AGC and Transient Stability Balancing and Harmonics Spinning and Short Short Circuit Term Reserves Replacement Governor Response Storage Reserves
Production Costing Market Simulation Expansion Planning Long Term Generation, Transmission, DSM, and DG Investments
Emissions Performance
TOOLS
Power Factory PSSE DigSilent
KERMIT Simulation Tool
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ProMod GE MAP
KEMA Energy Ecology Model Traditional T-Planning
Renewables Integration – Lessons Learned System level - Most installations wind & solar. - Maintaining grid operations biggest challenge. Transmission level - Renewables remote from load, creating T-issues. Distribution level - Significant impacts on distribution protection.
>20% penetration starts to become problematic 10
Challenges / Opportunities How to reduce integration costs? How to simplify system protection? How to simplify operations for operators? How to add predictive load curves? How to add predictive health monitoring? How to manage as utility revenue source?
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Integration Example – Lanai PV Intermittent Renewable Economic drivers, isolated grids, faster penetration
PV Application - One project can drive “% penetration” above 20% 3.5 MW peak ~4 MW generation 1 MV PV
The transmission system
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EXAMPLE - Geothermal (Base Load Renewable) St Kitts-Nevis-Puerto Rico HVDC Feasibility Study Connection routes - North or south? - Include St Croix? - Distance estimates HVDC terminals, mono or bi-polar, etc? Cable size / capacity Voltage levels, losses Capital costs for cables and terminals Impacts on power system at all terminals Cost savings / displaced fuels / other benefits 13
Nevis St Kitts
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Possible St Kitts-Nevis-Puerto Rico HVDC HVDC O/H
HVDC submarine cable
St Kitts-Nevis-Puerto Rico HVDC 15
Topics Part 1 – T&D System Challenges & Opportunities Part 2 – Effects of Solar on the Distribution System Part 3 – Role of the Smart Grid
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Distribution PV – Benefits Reduce conductor loading Reduce losses Delay capital upgrades Improve voltage control (access to inverter controls)
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Example - Distribution Feeder Distribution -
7.2 MW Peak 12.47 kV Rating 4.3 km (3-phase) 1 Transformer
PV Site - 1.18 MW - 1.0 PF
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Peak Demand Reduced & Shifted Reduced Demand
Shifted Peak
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40 kW PV on Tuvalu
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40 kW PV on Tuvalu (cont) 21
Tuvalu from the Air 22
Loss of PV Output – Substation Voltage PV Site Outage 1.05
1.3 Sub PV
1.1 1.02 1
1.01
Seconds
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700
650
600
550
500
450
400
350
300
250
200
150
100
0.9 50
1
PV Site
1.2
1.03
0
PU Voltage
1.04
Loss of PV Output – End-of-Feeder Voltage PV Site Outage 1
1.3 EOF PV
1.1 0.97 1
0.96
Seconds
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700
650
600
550
500
450
400
350
300
250
200
150
100
0.9 50
0.95
PV Site
1.2
0.98
0
PU Voltage
0.99
Intermittency of PV Output 3.5
Output (kW)
3 2.5 2 1.5 1 0.5 0 7:42
9:30
11:18
13:06
14:54
Time of Day
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16:42
18:31
Topics Part 1 – T&D System Challenges & Opportunities Part 2 – Effects of Solar on the Distribution System Part 3 – Role of the Smart Grid
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Definition of Smart Grid
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Communication Building Blocks SCADA
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Data Drives T&D Technology Advances
> Renewables Integration > AMI Installed > Substation Upgrades
> > > > > >
> > AMI Functional > Distribution Automation (DA) > Volt-VAR Control > System Protection > Local SCADA > Multiple Automation Platforms >
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Advances in AMI Advanced DA & Volt-VAR Controls Distribution Storage Deployed Utility Scale Storage Deployed Electrification of Transportation Integrated T&D Substations Advanced System Protection Cyber Security Measures
Key Elements of a Smart Grid
Distribution has bi-directional flows Great need for information exchange Integration of HVDC & power electronics Role of energy storage New concepts for operation & control New concepts for protection
Source: CIGRE Biennial Session - 2010 30
Example – Home Architecture
Source: IEEE Power & Energy, May/June 2010 31
Tonga from the Air 32
Backup Generator at Business in Tonga 33
Load Reduction by DSM Program
Source: KEMA Utility of the Future, Volume 3, 2010
www.dnvkema.com Ron Willoughby – Vice President DNV KEMA Energy and Sustainability United States of America