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Presentation Outline Wind/Diesel Power Systems Basics An overview of the market status of wind-diesel power systems and Examples • Current status of wind-diesel technology and its application E. Ian Baring-Gould, • System architectures and examples ofif operating systems Baring-Gould Ian Credit: Photo Kasigluk, Alaska National Wind • Recent advances in wind-diesel Technology Center & technology Deployment & • Remaining technical and Industrial Partnerships commercial challenges Centers

May 31st 2009 Photo Credit: Eolica San Cristobal S.A. Eolica Credit: Cristobal San Photo

San Cristobal, Galapagos

NREL is a national laboratory of the U.S. Department of Energy Office of Energy Efficiency and Renewable Energy operated by the Alliance for Sustainable Energy, LLC

Remote Power Systems Community Scale Hybrid Systems

Renewable based power system can be • Takes advantage of local renewable resources when used to supply a wide range of energy available in place of diesel produced energy needs including: • Centrally located power plants that distribute AC power to the connected homes. • Dedicated use: Water pumping/ice making. • Components of wind, PV, biomass, batteries and • House systems: Power systems for individual conventional generators homes, buildings, and load centers. • Use of batteries when appropriate to store renewable energy for use at night or low renewable times • Community Power Systems: Power systems for a whole community and can include • Generator used as backup or secondary power supply conventional generation, renewable • Incorporate larger or multiple generation units to improve technologies and storage technologies. operation performance and benefit from quantities of scale benefits • Community hybrid systems • Relatively mature market, understood technology • Wind/Diesel systems

Hybrid (Wind, PV, Diesel, Storage) Lime Village, Alaska Community System Small community in central Alaska using a Guyed Lattice Tower solar – diesel hybrid power system as part of Turbine Disconnect an AEA / Sandia National Laboratoryyg PV technologyy demonstration project – Average daily load peak of PV Charge Controller about 15 kW Turbine Controller – Successful technology

DC Source Center PV Array demonstration – Currently under monitoring • 12 kW Solar Array (Siemens & BP) Generator to assess economics and • 24 kW power converter Battery Bank Inverter or operational characteristics • 530 Ahr lead Acid battery bank DC Loads AC Loads bi-directional converter • 2 diesel engines

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Wind-Diesel Power Systems Current Status of Wind-Diesel Technology • Designed to reduce the consumption of diesel We have gone beyond conceptual – Pits cost of against cost of diesel power – Reduces diesel storage needs Oil price spike in 2008 have caused many nations and organizations to – Reduced environmental impact; fuel transport & emissions realistically look at options to reduce dependence on diesel fuel for • Used for larger systems with demands over ~ 100 kW power generation peak load up to many MW Rapidly expanding market for wind-diesel technologies: • Based on an AC bus configurations using wind turbines • 11 ppjrojects o peratin g or in construction in Alaska with 14 additional pjprojects and diesel engines funded • Operating projects in almost every region of the world • Batteries, if used, store power to cover short lulls in wind • Expanded interest in Canada, Caribbean and Pacific Islands, and Antarctica power But the challenges continue… • Large potential, varying degrees of maturity with fewer • Electricity is only part of the issue Heat examples Electricity • Limited education and management Transport • Obviously requires a good wind resource to be infrastructure “economical” • High capital costs % of energy usage in the rural community of • Lack of understanding of the technology Akutan, Alaska by sector

Wind-Diesel Penetration What’s the Challenge Behind Wind One of the critical design factors is how much energy is Diesel Power Systems? coming from the wind – called wind penetration – as this helps determine the level of system complexity By their nature renewable energy is stochastic Pow er Wind Power Output (kW) (uncontrolled) and it varies with the resource. Instantaneous nPenetratio = Primary Electrical Load (kW) We like our ppyower very constant and controlled – Used to understand control requirements - 60 Hz, 120 V – for our TV’s, lights, – Reactive power needs, voltage and frequency regulation computers Wind Energy Produced (kWh) n Penetratio Average Penetratio n = Turning the variable energy in the wind into Primary Energy Demand (kWh) constant, consistent energy we can use can – Generally calculated on monthly or annual basis – Total energy savings be a difficult task – the more energy from the – Loading on the diesel engines wind, the more complex the task – Spinning reserve losses/efficiencies

AC Based Hybrid System System Penetration

Penetration Penetration Operating Characteristics • Low penetration systems - Wind acts as a Class Peak Annual negative load, very little control or integration of wind Instantaneous Average ƒ Diesel(s) run full-time turbines into the power system is needed . ƒ Wind power reduces net load on diesel Low < 50% < 20% ƒ All wind energy goes to primary load • Mid penetration systems - Wind becomes a ƒ No supervisory control system major part of the power system but diesel engines ƒ Diesel(s) run full-time ƒ At high wind power levels, secondary loads dispatched to 20% – Medium ensure sufficient diesel loading or wind generation is 50% – 100% still prov ide much o f the sys tem power control . 50% curtailed Additional components and limited supervisory ƒ Requires relatively simple control system control required to assist diesels in maintaining power ƒ Diesel(s) may be shut down during high wind availability ƒ Auxiliary components required to regulate voltage and 100% - 50% – High quality. frequency 400% 150% ƒ Requires sophisticated control system • High penetration systems - Completely integrated power system with advanced control. These are really three different systems which Diesel generators shut off when not needed. Limited should be considered differently operational control of system by plant staff. Note: People play loose with the definitions

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Diesel Only Power System Low Penetration wind/diesel system

Wind Turbine 100 System Controller 100 Diesel Gensets 80 80

60 Diesel Gensets 60

40

40 20

20 0 06121824

0 -20 0 6 12 18 24 System Controller

-20 Time

Time

Village Load Village Load

Kotzebue, Alaska

• Large coastal hub community in Northwestern Low Penetration Alaska with a population of ~3,100 • Operated by Kotzebue Electric Association • Generally easy integration with existing diesel • 11 MW installed diesel capacity system, little or no diesel modifications • 2-MW peak load with 700-kW minimum load • 915-kW comprised of 15, Entegrity e50, required 50 kW; 1 remanufactured V17 75 kW; and 1 NW • Diesel engines provide all frequency, voltage 100/19, 100-kW wind turbine. • Instantaneous penetrations regularly above 50% otzebue Electric Assoc. Assoc. Electric otzebue

and reactive power control requirements K • Turbine curtailment used to control at times of high

• Switch gear would need to be modified to add Credit: Photo wind output turbines and turbine control software installed • Wind turbine of 13.3% • Modest fuel savings of up to ~20% possible. • Average penetration of ~5% with wind generating 1,064,242 kWh in 2007 • System support requirements. • Diesel fuel saving of more than 71,500 o Wind turbine maintenance. gal (270,600 l) in 2007 • Good turbine availability (92.8% 1/02 o No change in staffing or potential increase to 6/04) due to strong technical support Photo Credit: Kotzebue Electric Assoc. Assoc. Electric Kotzebue Credit: Photo

Medium-Penetration Systems Toksook Bay, Alaska Fairly well developed technology and controls Power system that supplies the ~800 people of the communities of • Diesel(s) run full-time although the use of modern or low-load diesels Toksook Bay and Nightmute in coastal Southwest Alaska improve performance • Power system operated by the Alaska Village Electric Cooperative • Secondary loads are used to maintain diesel loading • Average load just under 370 kW (both Toksook and Nightmute) • Wind generation can be curtailed, especially during high winds • 3 NW100-kW turbines and resistive community heating loads • Requires relatively simple control system • Installed in the fall and winter of 2006 • Power storage may be used to smooth power fluctuations • 24.2% average wind penetration with much higher instantaneous penetration Project examples include: • Almost 700 MWh generated by wind last year, saving almost 46,000 gal • Toksook Bay, Alaska (174, 239 l) o f fue l • Kotzebue, Alaska* • First year turbine availability of 92.4% - currently under warrantee • Kasigluk, Alaska • Average net capacity factor of 26.0% from Aug ‘07 to July ‘08 • Nome, Alaska • Mawson Station, Antarctica • San Cristobal, Galapagos • Denham, Australia

• Gracious, Azores Systems Power Northern Credit: Photo Photo Credit: Northern Power Systems Power Northern Credit: Photo

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Mawson, Antarctica High Penetration without Storage Plant that powers the Australian Antarctica 100 Very complex system with Windpower Research Station 80 • Installed in 2002-2003 very few operating examples: Load 60 • Four 120-kW diesels with heat capture • All diesels allowed to shut off Diesel • Two E30, 300-kW turbines when there is sufficient 40 excess wind in place to cover • Flywheel used to provide power 20 conditioning, although a diesel always load

0 remains operational • Synchronous condenser 0 6 12 18 24 • Electrical demand: 230 kW average used to control voltage & -20 it: PowerCorp Australia • Thermal demand: 300 kW average d provide reactive power

• Total fuel consumption of 650,000 l per Photo Cre • Dispachable and controlled year loads are used to maintain • Average penetration since 2002 is 34% power/frequency balance • Best monthly penetration is 60.5% in • Turbine power control likely April 2005 • Advanced system control • Turbine availability 93% required • Average fuel savings is 29% • Require a large dispatchable • Power station operation Web site: http://www.aad.gov.au/apps/operations energy sink such as heating

St. Paul, Alaska High Penetration with Storage Airport and industrial facility on the island of St. Paul in the Bering Sea Very complex system with only a few operating examples: • Owned and operated by TDX Power • Typically all diesels allowed to shut off when the wind produces more than • High-penetration wind-diesel system; all needed to supply the load diesels are allowed to shut off • Battery or fly wheel storage is used to smooth out power fluctuations while • One 225-kW turbine installed in 1999 and controlling system voltage and frequency when diesels are off two 150-kW diesel engines with a synchronous • Dispachable loads are used to productively use extra wind condenser and thermal • Low-load diesels can be used to support system performance • Current average load ~70kW electrical, ~50kW • Turbine power control likely thermal • Advanced system control • Since 2003, net turbine capacity factor of required 31.9% and a wind penetration of 54.8% • Less dependence on large • System availability 99.99% in 2007 energy sinks for excess wind • In March 2008, wind supplied 68.5% of the Few project examples but facility’s energy needs and the diesels only ran more systems being 198 hours ~27% of the time. contemplated • Estimated fuel savings since January 2005 (3.5 • Coral Bay, Australia* years) is 140,203 gal (530,726 l), which at • Wales, Alaska $3.52/gal is almost $500k • Annual fuel saving between 30% and 40%

Coral Bay, Western Australia Operation with Short Term Storage A small settlement of about 200 people on the western coast of Australia with 300 Operational data from high seasonal load 250 Wind the power system at • High penetration wind-diesel system 200 Load using a flywheel and low load diesels 150 Wales Alaska • Diesels remain on consistently 100 demonstrate system • Three Vergnet, 275-kW hurricane-rated 50 operation 0 turbines, a 500-kW PowerCorp flywheel Photo Credit: PowerCorp Credit: Australia Photo Power, kW Power, -50 1 14 27 40 53 66 79 92 105 118 131 144 157 170 183 196 • Battery bank covers short and 7x320-kW low-load diesel engines -100 lulls when wind energy can • Installed in summer 2007 by PowerCorp -150 Battery power (Charging is negative) Australia in collaboration with Horizon -200 not cover the load Power and Verve Energy -250 • Diesel started to cover prolonged gaps in wind • Average penetration for the first 10 months of operation was 55% 250 energy 200 • In September 2007, wind supplied 76% 150 • Large amounts of excess 100 of the community’s energy needs with 50 wind energy is not instantaneous penetrations 0 produced consistently above 90% 1 19 37 55 73 91 109 127 145 163 181 199 Diesel power, kW Diesel power, Time, minutes PowerCorp Credit: Australia Photo

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Wales, Alaska Issues of Power Generation and Remote coastal community in northwestern Alaska with a population of about 150 Transmission • Average load of around 70 kW • Two AOC 15/50 wind turbines Power Quality of Systems

• High-penetration wind diesel with the ability to Drouihet, Steve Credits: Photo Automation Sustainable operate with all diesels turned off using short-term • Variable renewable penetration of system NiCad battery storage with a rotary converter to control frequency and voltage • Power flow questions t, • Resistive loads used for heating and hot water • Voltage variation on feeder lines • System has had many problems associated with

complexity, maintenance, and confidence of the Drouihe Steve Credits: Photo Automation Sustainable • Level of technology/control existing in diesel local population to operate with all diesel engines plant offline • Operated by Alaska Village Electric Cooperative with the implementation assistance of Kotzebue Electric Association and NREL If at any time you are not producing enough power, power system will collapse Photo Credits: Steve Drouihet, Drouihet, Steve Credits: Photo Automation Sustainable

Elements of Power Quality Maintaining High Power Quality

• Power reliability: Having power when you should • Maintaining a high level of power quality is dependent have it. on obtaining ways to control what is happening. • Power Quality: Is the power supplied good enough • Depends on for the needs. – Configuration: Integrated solid state power power converter • Voltage: Amplitude of the power wave form. and controls, no storage with dump loads • Frequency: Maintaining a balance of power supply and – TdfitDilltidflType and age of equipment: Diesel electronic and fuel demand. controls • Power Factor maintenance & Reactive Power supply – System integration: Overall system control (VAR Support): All impedance devices require both active and reactive power. • There are supply and demand side solutions to this • Harmonics Distortion: The quality of the power that comes problem down the line and can impact electronic devices

Supply Side Options Complication with Uncontrolled Options that affect only the power system as Generation seen from the grid Why are hybrids a complicated control question and • Controlled Dump Loads: Fast acting devices that need special attention in regards to power quality? help to balance the generation and load • Synchronous Condenser: Provides reactive ppgower and controls voltage. • By their nature renewables are stochastic (uncontrolled) and vary with the resource. The • Power Storage: Flywheels or advanced power converters and small battery bank: Used to assist in amount of variation and thus the amount required managing power flows, power smoothing. control depends on the renewable resource being • Active Power Control Devices: Monitor grid used and the power system design condition and act to insure high power quality • Wind, river run hydro and solar technologies require • Active Renewable Control: Control power output adequate control to allow integration and insure of the renewable device. Power control or simply power quality turning off some of the units

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Active Renewable Control Demand Side Options Control of the offending power generation Control options that can be completed on the device to smooth out power output. grid side to support system power quality

• Controlled shut down of renewable devices • Load Dispatching: Active dispatchable of specific loads and making the distinction between critical and during high wind or low load periods non-critical loads • Active power control of renewable technology. – Dispatchable loads like resistance heating – Variable speed technology using power electronics – Loads shedding where non-critical loads are turned off – Protection of sensitive loads – Active wind turbine control, variable pitch blades • Capacitors Banks: Installation of capacitors to • Resource smoothing using multiple units smooth out rapid system fluctuations and partially – smaller turbines spread out over a greater area correct systems power factor. • Active Load Control: Replacing large inefficient • Short and long term forecasting of system loads with better or different devices power

Active Load Control System Operation

This principle may not be applicable in every How complex is it to operate these power setting and requires a higher degree of collaboration between the energy supplier and systems? energy consumer • Specific Use Applications: Working with high energy users to insure that equipment is operating properly. An ounce of prevention is worth a pound of ___ It really depends on what type of system • Water Heaters: In many communities electric water you are talking about… heaters are a large source of energy usage which can be controlled • Variable Electric Rates: Accounting for the different production costs of energy

System Operation Coyaique, Chile

• Large regional Low penetration systems distribution system • Can be operated as two independent power • 3x 660 kW wind turbines systems (wind/diesel), though active • 4.6 MW of mixed hydro integration is preferred. • 16.9 MW of diesel • Operators in full control of power system and use individual unit controls to turn components on and off as needed. • Manually operated through • May have some data monitoring to keep track local control center of what has happened • Turbines turned off during low load or high wind pereods

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San Clemente Island, System Operation California Mid penetration systems – • U.S. Navy island off San Diego • Diesel powered grid • Really must be operated as an • 850-950 kW avg; 1,400 kW peak integrated power system with 775 kW wind • Minimal supervisory control required • Some components in addition to the Older diesels require diesel used to maintain power quality the use of a • Monitoring becomes more important synchronous condenser to maintain voltage

System Operation St. Paul Alaska, USA • Island in the middle of the Bering High penetration systems Sea • Really must be operated as an integrated • Implemented by TDX and Northern power system Power Systems in 1999 • Advanced supervisory control required • Complex power system controller • IdiidlIndividual componen t con tro llers oversee specific operation • Since diesels are turned off, components added to maintain power quality • Monitoring becomes more important and remote diagnosis generally advised

Wind/Diesel Hybrid - Fully Integrated 10-Minute Data, NPS Hybrid Wind/Diesel Power System TDX Corp., St. Paul Island, AK, USA

300.0

Wind Turbines 100

80 250.0 Diesel Gensets

60 200.0

40 Diesel 1 Diesel 2 20 150. 0 Load Dump 0 0 6 12 18 24 100.0 WTG Power

-20 Tank deg C Synchronous Time Condenser 50.0 System Controller 0.0 Remote 33.544.555.566.5 Hot Water Monitoring Storage Tank Village Load -50.0 Day (June 99)

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Systems and Components Dispatchable Generators • Hybrid power systems are made up of separate pieces of equipment that are • Generators that can be brought together to form a cohesive power turned on with short notice. system – Diesel, Gas, Natural • Configuration and component size depend on Gas, Bio-gas the l oa d an d resource availa ble a t s ite • Usually require a lot of • Controlling the power systems is a maintenance 40 kW Diesel Generator complicated question, both logically and • Role depends on technically, especially as system penetration system design. 10 kW Diesel increases • Wide range of old and Generator w/ Fuel tank • Designers must understand the different new technology components and their use • Wide range of control

Wind Turbines for Hybrids Hybrid System Power Converters • Convert energy from DC to AC • Range in size from and back 300W to 750kW Trace Tech • Some units contain power system • Large AC turbines for 100 kW control converter diesel plants • Solid state or rotary systems

• Small turbines Baring-Gould Ian Credit: Photo • Solid state range in size from 1kW designed for remote Enteggyrety e15 Wales AK 156 to 300kW kW rotary • Rotary systems built to size applications, converter generally DC but also depending on needs AC being developed • Combined with batteries for Photo Credit: Tom Agnew Tom Credit: Photo • Self erecting or tilt up storage Reconditioned towers common WindMatic • Installed cost $3-6/W Xantrax 4kW

with production from Cate Austin Credit: Photo converter $0.10-0.20/kWh Northwind 19/100 B

Batteries Other Active Power Control • Many types – Lead Acid (deep cycle • Allows active control of and shallow cycle) grid stability –NiCad • Allows access to small • Two uses/sizing: amounts of instantaneous – Store energy to cover Low load diesels - power lidlong periods operate down to below 10% rated • Generally modular – Store power to cover power while • Spinning losses maintaining control short periods Flywheels - over voltage and provide short • Long research history, • Requires periodic frequency replacement term energy very short operational storage while experience • Sensitive to environment smoothing • Life dependent on use fluctuations in and the environment wind and load

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Secondary Dispatchable Power Smoothing and Conditioning Loads Controlled dump loads, Transportation synchronous condensers, • Snow machines - Not commercially available • ATVs - Several commercial manufactures and grid conditioners to • Trucks and cars - Large variety of light-duty electric control system voltage, and hybrid electric cars and trucks Univ. of Wisconsin frequency, and reactive Thermal loads Madison modified Polaris • District heating (water and space) systems power • Dispersed electric heating using ceramic • Help to control voltage and WtWater dlitidesalination balance active and reactive In many cases, detailed information on power needs on the grid dispatchable loads is limited – making assessment • Primarily used when all diesel difficult engines have been shut off • My provide limited “storage” • Has a standing loss Photo Credit: Ian Baring-Gould

Grid E-Ride Credit: Photo Bad Boy Buggy utility Photo Credit: Steve Drouihet, Sustainable Automation Sustainable Drouihet, Steve Credit: Photo E-Ride electric truck – being tested Conditioner EVS e-force sport ATV electric ATV in Greenland in Antarctica in 08/09

System Controls and Monitoring and Switch Gear Remote Access • The controller makes everything work • Remote access allows together oversight of system • Generally have central switch performance gear/controller and then individual • Enables real time controllers for each component system interrogation • Operates at very high speed to and troubleshooting monitor system stability while even when off site allowing general component control • With expert analysis • Can reduce staffing costs while system reduces increasing system performance maintenance and • Controllers are not created equal – down time

just because they say something is Automation Sustainable Drouihet, Steve Credit: Photo • Small incremental cost “wind ready” does not mean that it is

That looks simple – doesn't it? This is not a Simple Thing

Wind Turbine The design and implementation of power Guyed Lattice Tower systems is a complex matter and although the Turbine Disconnect models (and initial presentations) make it look silitiimple, it is never thtthat easy.

PV Charge Every power system is complicated, some Controller PV Array much less than others but you do need to Turbine Controller DC Source Center think about the design and how it will be Generator implemented. Battery Bank DC Loads AC Loads Inverter (bi-directional optional)

“Simple” DC based small power system

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Power system schematic Other Integration Issues Site 1.8 One-Line Electrical Diagram for BWC Installation (Chile Replication Project)

1-1/C #8 In many cases it makes sense to implement wind as 1-1/C #8 .5" EMT .5" EMT continuous Lightning Arrestor 2-1/C #8 Inverter 2-1/C #8 1-1/C #8 part of a complete system up-grade 1-1/C #8 G Ground Bar (or equivalent) 5.5 kVA, 1P 1-1/C #8 48VDC - 120VAC

G Neu Kohler Generator 50 A 5 kVA, 1P • Complications with old diesel and controllers to G 120 VAC Neu

No Neutral/Ground 2-1/C 4/0 Bonding Jumper 1-1/C #4 N G integrated and automated operation (DC) .5" EMT GND. ROD 2-1/C #8 11/C#81-1/C #8 50A or less Pos. Fused To Load Neg To Load G Solid Neg. • Need for more space in the power house 150A

30 KVA: Turbine 1.8 Turbine 1.8 36.1A Primary LP 1.8 1-1/C #4 Gnd • Modification to existing switch panels Down-Tower Control Room 480V/208V Disconnect Disconnect G 40A 40A G G G G G G WTG (BWC Excel R 7kW) DC Bus • Integration with existing thermal loops 120V, 3P, 3W 110A Rectifier/ Pos. Fused 1.5" EMT Voltage Regulator Solid Neg. 3-1/C #6 250A 1-1/C #8 GND. 1.5" RT Comp EMT 1.5" RT Comp EMT 2-1/C 1/0 Weld 3-1/C #6 Armored, Jacketed Cable 3-1/C #6 3-1/C #1 1-1/C #8 GND. 1-1/C #6 GND. 1-1/C #4 Gnd Pos. Fused Neg Solid Neg. No Negative/Ground 300A Connection GND. ROD WTG Controller Adds to the cost and becomes much more 1-1/C #2 GND. 2-1/C 1/0 Weld complicated and time consuming

1-1/C #8

Trojan T105 Battery Bank 48V, 52kWh

Conclusions

• There are a lot of options / configuration of hybrid power systems using local renewable resources to reduce the dependence on imported fuels for rural electricity generation. Questions? • Its not only the cost of imported fuels that need to be considered - the cost of fuel storage, transportation, and potential environmental impact should be assessed as well. • Options for larger communities include advanced diesels and control, locally derived bio -fuels & renewable technologies. • Projects should be implemented with the support of the whole community and as part of energy education/efficiency campaigns. E. Ian Baring-Gould • Several very successful wind-diesel projects have been National Wind Technology Center & implemented in arctic areas, but every project is not successful Deployment & Industrial Partnerships • Social sustainability issues dominate over technical ones Centers • Its never as easy as it seems 303-384-7021 [email protected] Renewable power systems, specifically wind-diesel, can be implemented successfully in remote areas

NREL is a national laboratory of the U.S. Department of Energy Office of Energy Efficiency and Renewable Energy operated by the Alliance for Sustainable Energy, LLC

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