Months after it hurriedly shut down new generators at its Garden of Eden generating facility, Guyana Power and Light (GPL) engineers have managed to pinpoint the possible cause having analyzed data collected and are now working on a solution.
GPL Chief Executive Officer (CEO) Bharrat Dindyal last week told Stabroek News that from all indications, it appears that the fuel separator built into the Wärtsilä engines to clean the Heavy Fuel Oil (HFO) was not functioning as it should.
He stated that with the design being relatively new on the market, the data to quickly pinpoint the issue was not readily available. The electricity generating sets installed at the Garden of Eden facility are of a hybrid design and they can utilise both HFO and gas.
According to Dindyal, with a new plant like this, its performance is closely monitored and evaluated. In the process should any issue arise, the engineers will quickly work to identify a cause and tweak the design to remedy the issue.
The CEO added that the Finland-headquartered manufacturer, Wärtsilä, is currently working to send parts here to rectify the situation.
Dindyal explained that from all indications the fuel filtering system was not working as it was designed to clean the HFO. When the filtration commences, the fuel is spun and passes through a centrifuge where the heavy particles are dropped out and the lighter fuel moves on through to the onboard centrifuge. Another filtering process occurs here before the fuel gets into the engine.
It is strongly believed that this is where the problem is and created the situation for the abrupt shutdown of the plant over fears that there could have been a catastrophic explosion.
As a part of the solution, the engineers are proposing that another HFO filtering system be installed parallel to main filter system. This would aid in the filtering capacity and the CEO added that once the parts arrive, they will install them on one of the generators. They will evaluate its performance before moving to install it on the other engines.
The CEO said that Wärtsilä will likely have to bear the cost for the additional fuel utilised in this process. In the contractual agreement, he noted, there is a provision for the manufacturer to cover the cost of fuel after it exceeds a specified amount.
He added that they are currently utilising lube oil testing kits to assess the quality of the lubricating oil being used. He explained that to keep the engines running at the moment, they are required to conduct a 10 per cent oil change every three days.
On January 14, GPL announced that it was forced to shut down the plant over fears of a massive explosion subsequent to the detection of fuel in the exhaust of a generator.
Dindyal had previously explained that the company’s technicians and engineers at the facility noticed the elevated temperatures on all of the generators, causing them to suspect something was amiss. He stated that the temperatures were about 2°C above normal. Having consulted with the engineers for the Finnish manufacturer, Dindyal said GPL made a decision to send samples of the lube oil to Houston, Texas for analysis. He disclosed that the results of the analysis showed that viscosity more than doubled and additives to neutralise acid in the lube oil were depleted by 50% to 60%.
Bharrat emphasised that the lube oil used in the engines is up to standard and that it has not contributed to the malfunctioning of the generators. The utility company’s CEO previously noted that there is no issue with the fuel or lube oil as the same type and grade have been procured to be used across the country.
“Since [19]93 we have been using the Shell brand of lube oil and grade at the generators across the country at Kingston, Sophia, Berbice… As a matter of fact some years ago we tried to use the Texaco brand but we had to immediately revert to Shell… so it is not a fuel or oil issue,” he explained.
Dindyal had previously said that with all suspected causes discounted during the troubleshooting, the company was left with analyzing the data collected.
The generating system at the plant, which is still to be commissioned, began supplying the national grid in November last year after completion of a testing phase.
In November 2020, the power company had received five generators from Finland. The five Wärtsilä generators can each generate 9.3 MW of power.
In October last year, Ryan Ross, Divisional Director of Engineering Services, had explained that the power plant will be a dual-fuel power generator. He stated that with the expectation of Guyana tapping into natural gas from offshore petroleum operations, the power plant is built to work with both heavy fuel oil and natural gas.
The old power generating plant had been costing GPL a large sum of money to maintain and Ross noted that with the generators being old, they are no longer efficient and finding spare parts proved difficult at times. The power plant was constructed in the 1970s and is equipped with engines that are over 26 years old. Ross had said that GPL does not plan on abandoning the old power plant when the new one comes on stream as they will need all the electricity generated for the national grid.
