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CURRENT INFORMATION ABOUT POWER OUTAGES

Thursday, July 18, 2019

Local Outage Notice for areas of Barrigada

Re: Scheduled Outage Notice
For Release: On Receipt
End Date: Wednesday, 24 July 2019 @ 2:00 p.m.

The Guam Power Authority advises that a power outage has been scheduled as follows: 

Wednesday, 24 July 2019
From 8:30 a.m. – 2:00 p.m.

The area(s) affected include:  Areas of Barrigada to include Capt. Reyes Way, Bejong Street, Crisostomo Street, Lower East San Vicente Street and customers in these surrounding locations.

REASON:  Line crews to perform maintenance work on poles and lin harewares to improve power quality and reliability.  The outage is necessary for GPA Line crews will be performing work on power lines or power line hard ware(s).

Customers using backup generators, please ensure your main breaker is in the OPEN position to ensure the safety of the GPA crews working on the lines.

GPA regrets the inconvenience caused to customers in these areas, but the outage is necessary as a safety precaution while the GPA crews are performing this work.

Your patience and understanding is appreciated.
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Wednesday, July 17, 2019

Local Outage Notice for areas of Tamuning

Re: Scheduled Outage Notice
For Release: On Receipt
End Date: Thursday, 25 July 2019 @ 2:00 p.m.

The Guam Power Authority advises that a power outage has been scheduled as follows: 

Thursday, 25 July 2019
From 9:00 a.m. – 2:00 p.m.

The area(s) affected include:  Areas of Tamuning to include Tan Antonia Camacho Street, East Espiritu Street, American Legion area and customers in these surrounding locations.

REASON:  Line crews to replace wooden pole to concrete pole and line hareware to improve power quality and reliability.  The outage is necessary for GPA Line crews will be performing work on power lines or power line hard ware(s).

Customers using backup generators, please ensure your main breaker is in the OPEN position to ensure the safety of the GPA crews working on the lines.

GPA regrets the inconvenience caused to customers in these areas, but the outage is necessary as a safety precaution while the GPA crews are performing this work.

Your patience and understanding is appreciated.
# # # # #

Editor’s note:  Customers, may also view this power outage information on GPA's Facebook page.

Local Outage Notice for areas of Tamuning

Re: Scheduled Outage Notice
For Release: On Receipt
End Date: Tuesday, 23 July 2019 @ 2:30 p.m.

The Guam Power Authority advises that a power outage has been scheduled as follows: 

Tuesday, 23 July 2019
From 8:30 a.m. – 2:30 p.m.

The area(s) affected include:  Areas of Tamuning to include Lagoon Street, Leon Guerrero Condo, Shirley's Restuarant and customers in these surrounding locations.

REASON:  Line crews to perform maintenance work to improve power quality and reliability.  The outage is necessary for GPA Line crews will be performing work on power lines or power line hard ware(s).

Customers using backup generators, please ensure your main breaker is in the OPEN position to ensure the safety of the GPA crews working on the lines.

GPA regrets the inconvenience caused to customers in these areas, but the outage is necessary as a safety precaution while the GPA crews are performing this work.

Your patience and understanding is appreciated.
# # # # #

Editor’s note:  Customers, may also view this power outage information on GPA's Facebook page.

Friday, July 5, 2019

Scheduled Outage Notice for the Barrigada area



Re: Scheduled Outage Notice
For Release: On Receipt
End Date: Thursday, 11 July 2019 @ 11:30am

GPA ANNOUNCES SCHEDULED POWER OUTAGE

The Guam Power Authority advises that a power outage has been scheduled as follows: 

Thursday, 11 July 2019
From 08:30am – 11:30am (3 hours)

The area(s) affected include:  Barrigada:  Nalao Road, R. Camacho Way, Capt. Reyes Way, Bejong Street, Crisostomo Street, Lower East San Vicente Street, Salas Drive, Tun Juan White Street, Borja Street, Chapel Road, Lujan Way, Simeon Street, Taitano Street, Manaitai Street, Canada Toto Loop, Taison Street, Blind Road, Bibic Street, Balako Street, Blas Street, Francisco Street, Manibusan Lane, Akaide Street, Sielboro Street and customers in the surrounding area.

REASON:  The outage is necessary as GPA Line crews will be performing maintenance work to improve power quality and reliability.

Customers using backup generators, please ensure your main breaker is in the OPEN position to ensure the safety of the GPA crews working on the lines.

GPA regrets the inconvenience caused to customers in these areas, but the outage is necessary as a safety precaution while the GPA crews are performing this work.

Your cooperation is appreciated.

# # # # #

Editor’s note:  Customers, may also view this power outage information on GPA's Facebook page

Scheduled Outage Notice for Santa Rita (Bordallo Subdivision)



Re: Scheduled Outage Notice
For Release: On Receipt
End Date: Wednesday, 10 July 2019 @ 2:30pm

The Guam Power Authority advises that a power outage has been scheduled as follows: 

Wednesday, 10 July 2019
From 09:00am – 2:30pm (5.5 hours)

The area(s) affected include:  Santa Rita:  Bordallo Subdivision (Santa Maria Street.)  and customers in the surrounding area.

REASON:  The outage is necessary as GPA Line crews are completing electrical power system upgrading of power poles, lines and hardware(s) to improve power quality and reliability.

Customers are further advised that numerous GPA heavy equipment vehicles will be working in the area, which may cause roadways and driveways to be blocked.

Customers using backup generators, please ensure your main breaker is in the OPEN position to ensure the safety of the GPA crews working on the lines.

GPA regrets the inconvenience caused to customers in these areas, but the outage is necessary as a safety precaution while the GPA crews are performing this work.

Your cooperation is appreciated.

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Editor’s note:  Customers, may also view this power outage information on GPA's Facebook page

Thursday, June 20, 2019

Scheduled Local Outage for areas of Yona

Re: Scheduled Outage Notice
For Release: On Receipt
End Date: Tuesday, 25 June 2019 @ 2:30 p.m.

The Guam Power Authority advises that a power outage has been scheduled as follows: 

Tuesday, 25 June 2019
From 9:30 a.m. – 2:30 p.m.

The area(s) affected include:  Areas of Yona to include M.U. Lujan Road, M.U. Lujan Elementary School, Cruz Road, Yona Softball Field, Tora Lane, Tilan Lane, As Ramon Road, Tila Lane, Fernandez Court and customers in these surrounding locations.

REASON:  Line crews to perform maintenance work to improve power quality and reliability.  The outage is necessary for GPA Line crews will be performing work on power lines or power line hard ware(s).

Customers using backup generators, please ensure your main breaker is in the OPEN position to ensure the safety of the GPA crews working on the lines.

GPA regrets the inconvenience caused to customers in these areas, but the outage is necessary as a safety precaution while the GPA crews are performing this work.

Your cooperation is appreciated.
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Editor’s note:  Customers, may also view this power outage information on GPA's Facebook page.

Scheduled Local Outage Notice for areas of Mongmong/Toto

Re: Scheduled Outage Notice
For Release: On Receipt
End Date: Wednesday, 26 June 2019 @ 3:00 p.m.

The Guam Power Authority advises that a power outage has been scheduled as follows: 

Wednesday, 26 June 2019
From 9:00 a.m. – 3:00 p.m.

The area(s) affected include:  Areas of Mongmong/Toto to include Clara Road, Ramos Lane, J.Q. San Miguel Guelo Yan Guela Street, Lujan Street & Lujan Way, Cesario Road and customers in these surrounding locations.

REASON:  Underground line crews to energize new underground line and replace poles.  The outage is necessary for GPA Line crews will be performing work on power lines or power line hard ware(s).

Customers using backup generators, please ensure your main breaker is in the OPEN position to ensure the safety of the GPA crews working on the lines.

GPA regrets the inconvenience caused to customers in these areas, but the outage is necessary as a safety precaution while the GPA crews are performing this work.

Your cooperation is appreciated.
# # # # #

Editor’s note:  Customers, may also view this power outage information on GPA's Facebook page.

Tuesday, June 18, 2019

Emergency Ouage Notice for areas of Talofofo


For Release:               On Receipt

End Date:                  18 June 2019 @ 6:00 p.m.

The Guam Power Authority announces that an emergency local outage notice is issued for the following locations:

Location:        Customers located in Talofofo from Laguna Estates towards Paraiso Estates subdivisions.
Date:               Tuesday, 18 June 2019
Time:              3:00 p.m. to 6:00 p.m.
Reason:           Line crews to replace existing line hardware to improve power quality and reliability. 

In addition, there will be two (2) 30 minute service interruptions beginning at 3:00 p.m. and another at 6:00 p.m. affecting customers from Talofofo substation towards Baza Gardens and other customers in these immediate locations.

GPA regrets the inconvenience caused to customers in these areas, but the outage is necessary as a safety precaution while crews are working.  Your patience and understanding is most appreciated.
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Monday, June 17, 2019

Schedule Outage Notice for areas of Barrigada/Mangilao

Re: Scheduled Outage Notice
For Release: On Receipt
End Date: Monday, 24 June 2019 @ 12:00 p.m.

The Guam Power Authority advises that a power outage has been scheduled as follows: 

Monday, 24 June 2019
From 09:00 a.m. – 12:00 p.m.

The area(s) affected include:  Southbound Route 10 from Barrigada substation towards Mangilao Dairy Road Traffic intersection and customers in the surrounding area.

REASON:  The outage is necessary for GPA Line crews will be performing work on power lines or power line hard ware(s).

Customers using backup generators, please ensure your main breaker is in the OPEN position to ensure the safety of the GPA crews working on the lines.

GPA regrets the inconvenience caused to customers in these areas, but the outage is necessary as a safety precaution while the GPA crews are performing this work.

Your cooperation is appreciated.

# # # # #

Editor’s note:  Customers, may also view this power outage information on GPA's Facebook page.

Scheduled Local Outage Notice for areas of Piti Vilage CORRECTED VERSION


The Guam Power Authority announces that a scheduled local outage notice is issued for the following locations:

Location: Customers located in Piti Village along TURNER ROAD and other customers in these immediate locations.

Date:               Wednesday, 19 June 2019

Time:              8:30 a.m. and 3:30 p.m.

Reason:          Navy line crews to install pole and line hardware to improve power quality and reliability.

GPA regrets the inconvenience caused to customers in these areas, but the outage is necessary as a safety precaution while crews are working.  Customers using backup generators, please ensure your main breaker is in the OPEN position to ensure safety to the line crews working.

The outage interruptions are necessary as a safety precaution to line crews as work is completed.  Your patience and understanding is most appreciated.
# # # # #

Friday, June 7, 2019

Local Interruption of Service Outage Notice for areas of Yigo

A local outage notice is issued for the following areas of Yigo:

Location:       Jesus Amparo St., Chalan Tun Jose Ameripino Ct., Trevor Highway,
                       Bobbie Lane, Benny Lane, Chalan Kafo, Wendy Lane and other    
                       customers in these immediate locations.
Date:              Tuesday, 18 June 2019
Time:              Interruption of servide at 8:30 a.m. and 9:30 a.m.
Reason:           Line crews to install pole and line hardware to improve power quality and reliability

Customers using backup generators, please ensure your main breaker is in
the OPEN position to ensure safety to the line crews working in the area.

GPA regrets the inconvenience caused to customers in these areas, but the outage is necessary as a safety precaution while crews are working.
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Local Outage Notice for areas of Santa Rita UPDATE

A local outage notice is issued for the following areas of Santa Rita:

Location:       Pale Ferdinand Way, Sumay Memorial St., Joaquin Perez St.,
                        Santa Rosa subdivision, San Pedro St., San Antonio St., San
                        Isidro Rd., Sgt. E. Cruz St., and other customers in
                        these immediate locations.
Date:               Thursday, 13 June 2019
Time:              10:30 a.m. to 2:30 p.m.
Reason:           Line crews performing repair work on line hardware to improve power quality and reliability

The following areas will have two 30 minute service interruption beginning at 10:30 a.m. and another
at 2:30 p.m:

Santa Rita:  Maria Perez Ct., Mormon Ct., Juan Lizama St., G.S. Borja Drive, Juan P. Sarmiento Dr., and other customers in these immediate locations.

Customers using backup generators, please ensure your main breaker is in the OPEN position to ensure safety to the line crews working in the area.

GPA regrets the inconvenience caused to customers in these areas, but the outage is necessary as a safety precaution while crews are working.
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Thursday, May 30, 2019

Scheduled Local Outage Notice for areas of Agana/Maite locations

A local outage notice is issued for the following areas of Agana/Maite:

Location:       ET Calvo area, Perez Lane, Titires St., Cliff Lane, Territorial College of Guam
                        Road, JA Camcho Road, JA Camacho Ave. and other customers
                        in these immediate locations.
Date:               Wednesday, 5 June 2019
Time:              8:30 a.m. to 2:30 p.m.
Reason:           Line crews performing repair work on line hardware to improve power quality and reliability

The following areas will have two 30 minute service interruption beginning at 8:30 a.m. and another
at 2:30 p.m.

Customers using backup generators, please ensure your main breaker is in the OPEN position to ensure safety to the line crews working in the area.

GPA regrets the inconvenience caused to customers in these areas, but the outage is necessary as a safety precaution while crews are working.
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Friday, May 24, 2019

Scheduled Outage Notice for Ghura 506 Yigo

Re: Scheduled Outage Notice
For Release: On Receipt
End Date: Thursday, 30 May 2019 @ 2:00pm

The Guam Power Authority advises that a power outage has been scheduled as follows: 

Thursday, 30 May 2019
From 09:00am – 2:00pm (5 hours)

The area(s) affected include:  Ghura 506 Yigo: Ababang Loop, Sasata Court, Babli Court and customers in the surrounding areas.

REASON:  The outage is necessary for GPA Line crews to change-out transformers to improve power quality and reliability.

Customers using backup generators, please ensure your main breaker is in the OPEN position to ensure the safety of the GPA crews working on the lines.

GPA regrets the inconvenience caused to customers in these areas, but the outage is necessary as a safety precaution while the GPA crews are performing this work.

Your cooperation is appreciated.

# # # # #

Editor’s note:  Customers, may view this power outage information on GPA's Facebook page.

Scheduled Outage Notice for Tumon Nikko Hotel and Gun Beach Area

Re: Scheduled Outage Notice
For Release: On Receipt
End Date: Sunday, 26 May 2019 @ 2:30pm

 The Guam Power Authority advises that a power outage has been scheduled as follows: 

Sunday, 26 May 2019
From 08:30am – 2:30pm (6 hours)

The area(s) affected include:  Tumon:  Nikko Hotel, Gun Beach and customers in the surrounding area.

REASON:  The outage is necessary for GPA Line crews are completing electrical power system upgrades to improve power quality and reliability.

Customers using backup generators, please ensure your main breaker is in the OPEN position to ensure the safety of the GPA crews working on the lines.

GPA regrets the inconvenience caused to customers in these areas, but the outage is necessary as a safety precaution while the GPA crews are performing this work.

Your cooperation is appreciated.

# # # # #

Editor’s note:  Customers, may view this power outage information on GPA's Facebook page.

Scheduled Outage Notice for Route 4 Chalan Canton Tasi (Inarajan)



Re: Scheduled Outage Notice
For Release: On Receipt
End Date: Wednesday, 29 May 2019 @ 2:00pm

The Guam Power Authority advises that a power outage has been scheduled as follows: 

Wednesday, 29 May 2019
From 09:00a.m. – 2:00p.m. (5 hours)

The area(s) affected include:  Route 4 Chalan Canton Tasi (Inarajan), Tun Jesus Crisostomo Drive, Tun Jose Chargualaf Drive, Tun Jesus D. Paulino Street, Tun Felipe Meno Drive, Liang Kin Chele Circle, Tipoku Street, Tun Santiago N. Paulino Street and customers in the surrounding area.

REASON:  The outage is necessary for GPA Line crews will be working on power poles, power lines and pole top hardware(s) to improve power quality and reliability.

Customers using backup generators, please ensure your main breaker is in the OPEN position to ensure the safety of the GPA crews working on the lines.

GPA regrets the inconvenience caused to customers in these areas, but the outage is necessary as a safety precaution while the GPA crews are performing this work.

Your cooperation is appreciated.

# # # # #

Editor’s note:  Customers, may view this power outage information on GPA’s Facebook page.

Monday, May 20, 2019

Scheduled Outage Notice for Merizo



Re: Scheduled Outage Notice
For Release: On Receipt
End Date: Tuesday, 23 May 2019 @ 2:30pm


The Guam Power Authority advises that a power outage has been scheduled as follows: 

Thursday, 23 May 2019
From 09:00am – 2:30pm (5.5 hours)

The area(s) affected include:  Merizo:  J.C. Arriola beach to sailboat sign area and customers in the surrounding area.

REASON:  The outage is necessary for GPA Line crews will be performing work on power lines or power line hard ware(s).

Customers using backup generators, please ensure your main breaker is in the OPEN position to ensure the safety of the GPA crews working on the lines.

GPA regrets the inconvenience caused to customers in these areas, but the outage is necessary as a safety precaution while the GPA crews are performing this work.

Your cooperation is appreciated.

# # # # #

Editor’s note:  Customers, may also view this power outage information on GPA's Facebook page.

Scheduled Outage Notice for Ghura 503 Area


Re: Scheduled Outage Notice
For Release: On Receipt
End Date: Thursday, 23 May 2019 @ 2:00pm


The Guam Power Authority advises that a power outage has been scheduled as follows: 

Thursday, 23 May 2019
From 09:00am – 2:00pm (5 hours)

The area(s) affected include:  Ghura 503; including Fern Terrace, Galayan Drive and Himakas Lane and customers in the surrounding area.

REASON:  The outage is necessary for GPA Line crews will be changing out (2) transformers to improve power quality and reliability.

Customers using backup generators, please ensure your main breaker is in the OPEN position to ensure the safety of the GPA crews working on the lines.

GPA regrets the inconvenience caused to customers in these areas, but the outage is necessary as a safety precaution while the GPA crews are performing this work.

Your cooperation is appreciated.

# # # # #

Editor’s note:  Customers, may also view this power outage information on GPA's Facebook page.

Thursday, May 16, 2019

Scheduled Outage Notice for Maite Area


Re: Scheduled Outage Notice
For Release: On Receipt
End Date: Tuesday, 21 May 2019 @ 2:30pm


The Guam Power Authority advises that a power outage has been scheduled as follows: 

Tuesday, 21 May 2019
From 08:30am – 2:30pm (6 hours)

The area(s) affected include:  Maite:  E.T. Calvo, Perez Lane, Titires Street., Cliff Lane, Territorial College of Guam Road, J.A. Camacho Road, J.A. Camacho Avenue and customers in the surrounding area.

REASON:  The outage is necessary as GPA Line crews are completing power line and power line hardware(s) maintenance to improve power quality and reliability.

Additionally, there will be two brief 30-minute interruptions at 09:00a.m., and when the work is completed:

The area(s) affected include:  Maite:  from First Hawaiian Bank to Ada’s Plaza

Customers using backup generators, please ensure your main breaker is in the OPEN position to ensure the safety of the GPA crews working on the lines.

GPA regrets the inconvenience caused to customers in these areas, but the outage is necessary as a safety precaution while the GPA crews are performing this work.

Your cooperation is appreciated.

# # # # #

Editor’s note:  Customers, may view this power outage information at guampowerauthority.com or on GPA’s Facebook page.


Wednesday, May 15, 2019

Scheduled Outage Notice for Ghura 505


Re: Scheduled Outage Notice
For Release: On Receipt
End Date: Wednesday, 22 May 2019 @ 1:00pm


The Guam Power Authority advises that a power outage has been scheduled as follows: 

Wednesday, 22 May 2019
From 09:00am – 1:00pm (4 hours)

The area(s) affected include:  Ghura 505; parts of Guamamela Lane, Mapola Loop and Kamia Court and customers in the surrounding area.

REASON:  The outage is necessary for GPA Line crews will be replacing two (2) padmount transformers to improve power quality and reliability.

Customers using backup generators, please ensure your main breaker is in the OPEN position to ensure the safety of the GPA crews working on the lines.

GPA regrets the inconvenience caused to customers in these areas, but the outage is necessary as a safety precaution while the GPA crews are performing this work.

Your cooperation is appreciated.

# # # # #


Scheduled Outage Notice for Ipan, Talofofo


Re: Scheduled Outage Notice
For Release: On Receipt
End Date: Tuesday, 21 May 2019 @ 2:30pm

GPA ANNOUNCES SCHEDULED POWER OUTAGE

The Guam Power Authority advises that a power outage has been scheduled as follows: 

Tuesday, 21 May 2019
From 09:00am – 2:30pm (5.5 hours)

The area(s) affected include:  Ipan Talofofo:  Padua Lane and customers in the surrounding area.

REASON:  The outage is necessary for GPA Line crews are completing electrical power system maintenance to improve power quality and reliability.

Additionally, there will be two brief 30-minute interruptions at 09:00a.m., and when the work is completed:

The area(s) affected include:  Ipan, Talofofo: Cruz Heights

Customers using backup generators, please ensure your main breaker is in the OPEN position to ensure the safety of the GPA crews working on the lines.

GPA regrets the inconvenience caused to customers in these areas, but the outage is necessary as a safety precaution while the GPA crews are performing this work.

Your cooperation is appreciated.

# # # # #

Friday, May 10, 2019

Scheduled Outage Notice for Tumon



Re: Scheduled Outage Notice
For Release: On Receipt
End Date: Tuesday, 16 May 2019 @ 2:30pm


The Guam Power Authority advises that a power outage has been scheduled as follows: 

Thursday, 16 May 2019
From 08:30am – 2:30pm (6 hours)

The area(s) affected include:  Tumon:  Nikko Hotel, Gun Beach and customers in the surrounding area.

REASON:  The outage is necessary for GPA Line crews are completing electrical power system upgrades to improve power quality and reliability.

Customers using backup generators, please ensure your main breaker is in the OPEN position to ensure the safety of the GPA crews working on the lines.

GPA regrets the inconvenience caused to customers in these areas, but the outage is necessary as a safety precaution while the GPA crews are performing this work.

Your cooperation is appreciated.

# # # # #

Tuesday, May 7, 2019

Scheduled Outage Notice for Merizo


Scheduled Outage Notice for Merizo

For Release:  On Receipt
End Date:  Thursday, 09 May 2019 @ 12:30pm

The Guam Power Authority advises that a power outage has been scheduled as follows: 

Thursday, 09 May 2019
From 09:00am – 12:30pm (3.5 hours)

The area(s) affected include:  Merizo:  Area from J. Baza Street, Merizo North to Bear Rock area, Inarajan and customers in the surrounding area.

REASON:  GPA Line crews will be working on power lines and power line hard ware(s) to improve power quality and reliability.

Customers using backup generators, please ensure your main breaker is in the OPEN position to ensure the safety of the GPA crews working on the lines.

GPA regrets the inconvenience caused to customers in these areas, but the outage is necessary as a safety precaution while the GPA crews are performing this work.

Your cooperation is appreciated.

# # # # #

Friday, May 3, 2019

Scheduled Outage Notice for Tumon


Re:  Scheduled Outage Notice
For Release:  On Receipt
End Date:  Wednesday, 08 May 2019 @ 1:00 P.M.

The Guam Power Authority advises that a power outage has been scheduled as follows: 

Wednesday, 08 May 2019
From 09:00am – 1:00pm (4 hours)

The area(s) affected include:  Tumon:  Summerville Upper Tumon buildings E,F,G also I and N;  and customers in the surrounding area.

REASON:  GPA Line crews will be changing out two(2) padmount transformers to improve power quality and reliability.

Customers using backup generators, please ensure your main breaker is in the OPEN position to ensure the safety of the GPA crews working on the lines.

GPA regrets the inconvenience caused to customers in these areas, but the outage is necessary as a safety precaution while the GPA crews are performing this work.

Your cooperation is appreciated.

# # # # #

Thursday, May 2, 2019

Explaining The Short Intermittent Power Outages GPA Customers Are Experiencing

GUAM POWER AUTHORITY

The short outages you may experience in your area may be due to the loss of a generator or solar photovoltaic (PV) farm; resulting in the island wide power system automatically dumping your circuit in order to prevent an island wide black out. This is an ongoing problem which is explained herein.  GPA is constructing 40 megawatts of energy storage batteries to be completed in 2019, to mitigate these types of outages. 

The Guam Power Authority appreciates your understanding and patience as GPA works to resolve this issue.
                            UNDERSTANDING SHORT, INTERMITTENT POWER OUTAGES 
AFFECTING THE ISLAND WIDE POWER SYSTEM

Guam’s island wide power system operates as an isolated grid, making it more vulnerable to issues that may result in a total system blackout. One issue includes the sudden loss of generation. This may arise from a generator going offline or a large reduction in power output from solar photovoltaic (PV) systems, due to passing clouds or inverter trips.  GPA must supply the exact power as required by customers for stable grid operation. If GPA online generators cannot ramp up their output fast enough to makeup this balance, the system automatically drops load to bring the demand and generation back into balance. The time to effectively act to prevent a blackout for the Guam grid is much shorter than it takes to bring new generation online, so GPA must rely on fast-acting automatic system protection.

GPA uses an “under frequency load shedding” (UFLS) system protection scheme to protect the grid from a sudden loss of generation. UFLS helps stabilize the power system preventing a black out, as it allows the system to recover.  The UFLS uses several levels or stages of protection relays that would load shed distribution feeders. The relay levels are set to load shed at different frequency set-points and at different time delays after sensing decreases in frequency. GPA uses several stages of load shedding to match the generation lost to the system.

GPA groups distribution feeders in 20 to 25 megawatt blocks and assigns them to one of five stages of UFLS.  Once customers on the first stage experience 10 events of load shedding, these feeders are rotated by GPA engineers and relay teams, so that the customers in the UFLS scheme have some relief from the outages experienced. Stage 1 activates first. If more than 20 to 25 megawatts are needed to be load shed to make up the generation shortfall, then the next stage(s) may also then be activated. Thus, higher stages activate less frequently than the stage below it. UFLS outages on these circuits are usually less than 5 minutes. Some feeders, such as those serving hospitals and other critical infrastructure or services, are not placed into the UFLS scheme.

Photovoltaic (PV) solar energy fluctuates with the weather and can ramp up or ramp down quickly without warning. Passing clouds, on an otherwise sunny day, can adversely affect the output of solar PV systems onto the grid. GPA’s current generators cannot react fast enough to make up for large and fast drops in solar production.

GPA’s new base load power plant will use the latest “flexible” generation technology and will react more quickly than current generators. The new generation will quickly and easily smooth out the intermittent power output of solar PV systems. GPA’s intention is for the new power plant, along with energy storage batteries, to almost completely alleviate load shedding events caused by drops in total solar production and the sudden loss of generation.
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