© Copyright 2013, First Solar, Inc.
© Copyright 2013, First Solar, Inc.
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Key Messages
• Utility‐scale PV power plants are a growing part of Australia’s energy mix and have the necessary tools to actively support grid stability
• The Australia grid has a number of unique characteristics that challenge the way power plants need to be operated, particularly in regional areas
• Utility‐scale PV is modular in nature, therefore the key enabler to maintaining power quality is a power plant controller
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First Solar at a Glance
Invests more in R&D than any other solar company
Strongest financial stability & bankability in the industry
Industry leading efficiency improvement roadmap
Over 10GW installed worldwide and a 2.6GW contracted pipeline
Founded in 1999 and publicly traded on Nasdaq (FSLR)
Proven technology performance in Australia
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Topaz Solar Farm
World’s Largest PV Plant in Operation
Nyngan Solar Farm
Largest PV Plant in Australia – currently under construction
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Key Differences in the National Electricity Grid
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Power Quality Differences in Australia
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Power Grid
First Solar Grid Integration and Plant Control System
• First Solar has been a pioneer in developing its own grid integration and plant control system in the PV industry, requiring no customer development
Real‐time ControllersSatellite Imagery
Transformer
Inverters
PV Module Arrays
CombinerBoxes
Power Conversion Station (PCS) Photovoltaic Combining Switchgear (PVCS) Substation
Plant SCADA system
• Checks grid’s actual conditions and required set points
• Sends individual instructions to each inverter based on location, losses, and performance
• Controls quality of power coming out of the PV plant
All every 100 milliseconds!Short Term Forecasting
Set Points
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Why are Plant Controls Important for Utility-Scale PV Power Plants?
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2000
4000
6000
8000
10000
12000
Power (M
W)
Time Stamp (Seconds)
10MW Greenough River Solar Farm ‐Western Australia
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Grid Support Functions and Controls
Voltage, VAR control and/or power factor regulation
Fault ride through
Real power control, ramping, and curtailment
Primary frequency regulation
Frequency droop response
Short circuit duty control
Modern solar PV plants can now contribute to the reliability and efficiency of grid operation by offering the following capabilities:
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Plant Controls - Voltage Regulation
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“Utility Scale” Active Power Control
Reduced Power
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Without a Plant Control System
Plant Output Limit
Inverter Curtailed Locally
Plant Output Limit
Inverter Curtailed Locally
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Benefit of Plant Level Control System
Plant Output LimitPlant Output Limit
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Dynamic Power Factor Regulation
Source: Agua Caliente PV Plant in Yuma, Arizona, USA May 23, 2012. ~212MW on‐line.
Command Power Factor
Power Factor Set Point Changed from 0.98 to 1.0
Reaches 90% Steady State Value in ~ 3.2 seconds
Inverters Change VAr Output
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• Power Curtailment at Different Levels
Source: Agua Caliente PV Plant in Yuma, Arizona, USA March 13, 2012. ~90MW on‐line.
Plant Curtailment Test
Set PointReduced
Set PointIncreased
Ramp rates between set point changes are controlled
Inverters are Turned Down/ OFF to curtail output
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• Stopping and Starting One Block (30MW)
Source: Agua Caliente PV Plant in Yuma, Arizona, USA March 13, 2012. ~90MW on‐line.
Ramp Rate Controls
Plant StopCommand
Plant StartCommand
Inverters are Started in SequenceInverters are
Turned Off in Sequence;Ramp Rates are Controlled
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What Makes a PV Plant “Grid Friendly”?
First Solar’s plant optimization and grid integration is unmatched in the PV industry
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Future Improvements – Larger PV Plants & Solar Forecasting
As plants become larger… high frequency variability reduces.
Average Irradiance
Total Power
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Single Location
20 Bundled Locations
One‐minute Global Irradiance (W/sq.m)
One‐minute Global Irradiance (W/sq.m)
Future Improvements - Aggregation of Plants Reduces Variability
Spatial diversity of solar plants reduces aggregated variability… minimizing grid impact as the number of solar plants increase
Source: “Implications of Wide‐Area Geographic Diversity for Short‐Term Variability of Solar Power”; Andrew Mills and Ryan Wiser, Lawrence Berkeley National Laboratory, September 2010
Source: Hoff et al. 2008
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Conclusions
• Modern PV plants can contribute actively to grid stability and reliability
• In the future PV variability can be better managed through site diversity and improved solar forecasting
• PV power plants offer a cost‐effective energy resource
• Lessons learned to date on Renewable Integration— Large‐scale PV has been successfully integrated into grids
worldwide— No reported issues due to often cited barriers: PV variability,
harmonics, DC current injection, anti‐islanding failure or protection coordination
— Bulk energy storage has not been necessary for variable generation integration