-new technology being introduced to strengthen national power grid

THE Wales gas-to-energy project continues to take shape, with work on transmission and control technologies being introduced as part of the infrastructure that will connect the facility to Guyana’s national power grid.

During a recent site visit to the project, Guyana Power and Light Inc (GPL) System Planning and Research Manager Dhanraj Bachai highlighted several of the technologies being incorporated into the system, including advanced carbon-fibre-core conductors, a 30-megawatt battery-storage system and Automatic Generation Control (AGC). Bachai said the new systems will increase transmission capacity, improve reliability and allow GPL to respond more efficiently to changes in electricity demand.

He said the 230 kv transmission infrastructure is being designed to carry approximately 300 megawatts per circuit, while the battery will provide temporary support in the event of a generator failure, helping to maintain a continuous and dependable supply of energy to the national grid.

Earlier this week, Minister of Public Utilities and Aviation, Deodat Indar, said the initial phase is designed to deliver a major boost aimed at stabilising supply amid soaring demand driven by El Niño conditions.

With the minister noting that testing of the turbines are slated to begin in December, Bachai said that major connectivity steps are underway.

“We are going to have four gas turbines, where two gas turbines are going to feed into one steam turbine, from which we will get a total of 300 megawatts.  That total 300 megawatts is going to step up from 13.8 kV to 230 kV,” he said adding, “From that point, via our 230 kV lines, power will then go towards  [the] Goedverwagting substation on the eastern side, where it will be stepped down to 16 kV, and then to 13.8 kV. At 16 kV, it will interconnect with our existing DBIS, and the 13.8 kV will go directly to customers within the East Bank of  Demerara.”

This process will work to effectively bring relief to persons that are currently being served by the new Georgetown substation and the Golden Grove substation.

Beyond the generation capacity, Bachai highlighted the battery-storage system that will form part of the facility and provide an additional layer of reliability to the grid.

“At this facility, we are going to have a 30-megawatt, one-hour battery that is essentially placed here to mitigate a contingency event. In the event of a gas turbine trip or a steam turbine trip, that battery will automatically step in [and] be able to narrow that supply-demand gap, therefore enabling continuous and reliable power to be delivered to the grid,” he explained.

Moreover, Bachai pointed to improvements being made at the Guyana National Control Centre, where operators will have greater visibility and control over the generation units at the facility. “At the Guyana National Control Centre, the operators at that end will be able to see every single generator unit, referring to the gas turbines, the steam turbines and the battery,” he added.

Further, he said, “As a result of that, we will be able to have better management and control of the power that is going to be dispatched from this power plant and going onto the grid and all the different parts of the country.”

According to Bachai, the control centre will also introduce Automatic Generation Control (AGC), which he described as a first for Guyana. The system will allow generation units to automatically adjust their output when there are significant changes in demand.

In elaborating on this, he said, “Importantly also, at our control centre, we are going to have a very special feature. I must say special because it is the first time we are going to have this feature in Guyana.”

He added, “It is called Automatic Generation Control. It is software that is going to be able to automatically ramp up or ramp down these generator units in the event of massive changes in demand on the grid.”

Bachai explained that the system will be particularly useful in cases that may see a customer place an increased load on the grid, creating the need for additional generation capacity to stabilise the frequency.

This addition, he noted, also ensures that the project is up to standard with modern power-generation requirements. “That is when the AGC will step in and automatically do that for us. At the moment, we do that manually. So, for our grid code, that is a mandatory requirement for all modern power-generation facilities,” he said.

Another major technological addition will be seen in the transmission infrastructure, with the project marking the first time ACCC conductors are being introduced in Guyana.

“These are advanced, modern types of conductors that will offer us a significant increase in transmission capacity and reliability, because the core carries carbon fibre instead of steel or aluminium,” Bachai explained.

He said the construction of the cables and the chemistry of the aluminium will also allow electricity to be transferred more efficiently and effectively.

“One of these circuits at 69 kV, for example, can carry approximately 96 MVA,” he said, adding that three single circuits will be used to interconnect the Wales Industrial Substation, giving the infrastructure a combined capacity of three times 96 MVA.

The transmission line will then run towards the Vreed-en-Hoop substation, where the facility will be interconnected into the Demerara-Berbice Interconnected System (DBIS) through the existing substation.

Furthermore, Bachai explained that the higher-voltage 230 kV transmission lines will be capable of carrying significantly more power, using the same type of conductors.

“On the 230 kV line, by increasing the voltage and utilising the same conductors, we can carry more power,” Bachai said.

He noted that while the 69 kV circuit has one conductor per phase for each circuit, the 230 kV circuit will have two conductors per phase.

“In other words, each circuit can carry approximately 300 megawatts,” he said.

Bachai noted that the transmission infrastructure is being designed to ensure that the power generated at the facility can be reliably dispatched to customers across the region, as well as the nation.

“Our transmission infrastructure that we are building here today is definitely catered for, and evidently catered to, ensure that this plant is facilitated with the relevant or requisite transmission infrastructure to dispatch the power reliably to our customers across the country,” he said.