GPL blames botched tree trimming and burnt jumper for recent blackouts

The Guyana Power and Light says its coastal power supply is returning to normalcy.

According to Acting Chief Executive Officer (CEO) at GPL, Renford Homer a botched tree trimming exercise and a burnt jumper among other things are to be blamed for the recent spate of blackouts.

Following a spate of blackouts over the weekend and on Monday and Tuesday, an article appeared in a local daily criticizing the power company for its failure to offer an explanation to persons affected.

The power company stated that the shutdown to the Demerara Berbice Interconnected System (DBIS) on Sunday (August 30, 2017) was as a result of a generation shortfall from reduced generation reserve.

Homer explained that when the demand was about 84 megawatts, there were 87 megawatts available for generation which left only three megawatts of reserve capacity instead of the normal 20 megawatts.  In addition to this, the machines at Skeldon and Garden of Eden were being overhauled, whilst the one at Kingston was undergoing routine maintenance.

“The machine at Kingston developed a high exhaust temperature and that activated the generation protection which brought the machine offline. So we could call it a generator trip, because there was not much reserve and we could not unload the feed as quickly as we would’ve wanted to, to keep the system stable,” Homer said.

On Monday (July 31, 2017) at approximately 15:15 hours, GPL said it received a report of a burnt jumper on one of their feeders to which the transmission distribution crew quickly responded. However, it was noted that while attempting to close that feeder, the system sensed an unusual surge of high current and the protection network was activated taking the generating system offline. This resulted in sufficient generation to meet the demand at that time, the Acting CEO said.

Meanwhile, on Wednesday morning at approximately 8:45 hours, some customers on the DBIS experienced a disturbance when a number of feeders were lost due to a tree trimming exercise conducted by Atlantic Hotel Incorporated on Battery Road, Kingston.

Homer pointed out that the trimmed branches fell across GPL’s primary network causing a severe movement on two of the conductors which became intertwined which resulted in generation at Kingston plant going offline.

“It was not a total shutdown, we were able to offload a number of feeders and maintain some stability to the system. The two circuits that stayed out for a little bit would’ve been the F8 and the F9 feeders; parts of the F8 mainly.”

The F8 feeder covers Woolford Avenue, Battery Road, Kingston, New Market, Hadfield, Robb, Regent, Church and Charlotte streets, Brickdam, Homestretch Avenue, Solomon Place, Middle Street east of Camp street, east of Thomas street, Thomas Road, while F9 feeder covers Kitty.

Additionally, the Acting CEO promised that residents from Anna Regina and Charity in Essequibo, Region Two would have received normal supply of electricity by the end of Thursday, August 04, 2017.

He noted that on August 01 the number four cylinder on the aged Wartsilla engine experienced a fault causing it to be out of service.

Homer highlighted that due to this, just over two megawatts of available capacity was lost “so there was a load shedding schedule between Anna Regina and Charity. There were some villages between Anna Regina and Charity which received electricity for 12 hours then the other villages received for the remaining 12 hours.”

To correct this problem, the power company had corrected the situation by converting large portions of the Essequibo coast to 60 cycles. This he said, provided more generation reducing the load on the 50 cycles’ circuits, “where we were challenged with generation having over just over two megawatts of capacity.”

The Acting GPL CEO apologised for the inconvenience and is urging citizens to be careful when carrying out exercises close to GPL’s network since they can cause significant disruption and inconvenience, which in some instances translate to additional costs for the power company.

(Extracted and modified from Department of Public Information)