Crews are drilling from both sides of the Demerara River to install a new 69-kilovolt power cable that will create a ring transmission system for electricity generated by the Gas-to-Energy plant at Wales and strengthen the supply to West Demerara.
The cable, which will connect the Kingston and Vreed-en-Hoop substations, is being installed approximately 75 feet below the riverbed using horizontal directional drilling.
During a visit to the Vreed-en-Hoop work site, Minister of Public Utilities and Aviation Deodat Indar said the project would provide Guyana Power and Light (GPL) with a second transmission route across the river and allow electricity to continue flowing if one connection is taken out of service.
In a video shared on GPL’s Facebook page, he said the project was particularly important given the increase in electricity demand in Region Three, which has moved from approximately 36 megawatts to 41 MW.
The existing submarine cable, according to Indar, has been damaged several times and has limited capacity. Although the cable is rated to transmit approximately seven megawatts, he said it had recently been carrying as much as 15 MW.
If that cable is damaged, the minister said, GPL would have difficulty supplying the region with the electricity required to meet its current demand.
Indar said the new crossing would complement the transmission infrastructure being constructed to move electricity from the 300-MW Gas-to-Energy power plant at Wales.
At present, he explained, the transmission system does not have a complete ring circuit. The new cable would allow electricity transmitted from Wales to reach the Kingston substation by way of Vreed-en-Hoop, creating an alternative route within the network.
The minister said this redundancy was necessary to improve the stability and reliability of the Demerara-Berbice Interconnected System.
GPL Executive Management Team Leader Kesh Nandlall, in a separate video also provided an update from the work site, said the project would support the transmission of electricity between Regions Three and Four while enabling the utility to respond to rising demand.
He said the drilling work was progressing and that the cable and related materials had already been procured.
The project includes two underground carrier pipes that will accommodate the cables required for a double-circuit transmission crossing. The Kingston and Vreed-en-Hoop substations are also to be expanded to receive and transmit the additional electricity, while a new 69-kV gas-insulated switchgear installation is planned for Kingston.
HDDT International
Shayne Hicks of HDDT International, which is undertaking the horizontal directional drilling, in a third video said crews are working from both the Kingston and Vreed-en-Hoop sides and are expected to meet beneath the river.
“We are drilling from both sides. We are drilling from the Kingston side and we are drilling from this side here. We are going to meet in the middle of the river,” Hicks said in a video shared by GPL.
He said the crossing was being completed using an “intercept drilling” technique.
Crews are first drilling a pilot hole beneath the river using a 12¼-inch bit. A gyro survey instrument is being used to guide the drilling and ensure that the two sections meet at the intended location.
“Once we make the intercept, it’s called intercept drilling. Once we make the intercept, we follow the bit through to the other side,” Hicks explained.
After the pilot connection is completed, a reamer, or hole opener, will be attached and pulled through the passage to enlarge it. The opening will then be prepared for the installation of a DN500 SDR9 carrier pipe.
According to Hicks, the first carrier pipe will be transported to the site on a low-loader and pulled beneath the river from Vreed-en-Hoop to Kingston. The equipment will then be shifted by approximately two metres and the drilling process repeated for the second pipe.
Because the cables will be installed well below the riverbed, Indar said they would be protected from ships using the channel and would not impede plans to dredge the Demerara River to accommodate vessels with deeper drafts.
The minister described the installation as highly technical and said protective chambers would be constructed at both ends of the crossing to secure the cables.
As previously reported by Kiskadee Watch, the new crossing is intended to replace an existing river link that is decades old and limited in capacity.
A separate cable has already been laid between Sussex Street and Vreed-en-Hoop as an interim measure to provide West Demerara with an additional transmission route while the main Kingston crossing is being completed.
The project forms part of GPL’s wider expansion of the national grid, including new substations, transmission lines, distribution feeders and battery-storage facilities. The interconnected system recently recorded peak demand of approximately 246.2 MW.
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