Enemalta says Delimara turbine will be repaired at BWSC’s expense

While Enemalta admitted that the steam turbine at the new Delimara power plant extension is damaged, it insisted that the damages will be paid for by Danish contractor Bwsc. It also stressed that the plant is still operational.  

On Tuesday, Labour MP Joe Mizzi said the new turbine suffered serious damage during a test run and claimed that the plant is not operative.

In reply to Mizzi's claims, Enemalta said it is addressing the issues raised in Parliament on Tuesday and noted that investigations are currently being carried out by Bwsc and the manufacturer of the steam turbine.

Enemalta pointed out that Bwsc is currently attempting to repair the damage in the shortest possible time. "It has to be noted that all the plant is still under the responsibility of Bwsc who will have to rectify the damage at their expense. In fact, Enemalta has already sought legal advice on how to safeguard its interests."

It stressed that the plant is still operational and said: "Furthermore, contrary to the implication made by Mr Mizzi , there are no faults affecting the satisfactory operation of the abatement system which is working efficiently with emissions being significantly below those stipulated by legislation," Enemalta said.

In a statement the corporation said the Delimara extension is made up of eight diesel engines with an aggregated electrical output of 136MW, an abatement system to reduce emissions, a heat recovery system and a steam turbine.

The heat recovery system is an ancillary part of the plant which takes the heat from the exhaust of the eight engines, transfers it to water to produce steam which in turn rotates the steam turbine to produce electricity.

This system, known as combined cycle, increases the efficiency of the plant since it is using heat which normally would be discarded.

"One needs to stress that before Enemalta takes over the new Delimara extension, all the plant needs to go through a rigorous process of testing consisting of commissioning, reliability and performance tests," the corporation said.

It added that following the completion of the commissioning and reliability tests, a fault was identified on the steam turbine stop-valve.

"Investigations revealed that this fault was caused by parts of the strainer, installed just in front of the steam turbine, which had dislodged. Some of these parts also passed into the steam turbine causing foreign object damage and which is currently being investigated by the manufacturer," Enemalta explained.

The corporation added that the purpose of the reliability tests is to demonstrate and verify the correct operations of the plant under all commercial operation scenarios.

It said that it is not the intention of these tests to operate the plant continuously at full load.  "The plant is designed to be operated on a start/stop basis in order to optimize the operating efficiency while meeting the varying daily load demand. This process is inherently more demanding than continuous operations. It is part of the normal procedure that whenever generating units are shut down routine checks and maintenance are carried out."

Enemalta also rebutted Mizzi's claims on the leakage of toxic emissions and described them as "incorrect." It denied that there have been leakages of sulphur emissions from the plant resulting in a health hazard to the personnel on site.

However, Enemalta confirmed that there have been minor discharges of sodium bicarbonate (commonly known as baking powder) which is used in the abatement process and dust from the valves of the abatement plant and the waste unloading system.

The corporation said these faults are being corrected and the valves are being replaced or modified. It added that these discharges have nothing to do with the fault on the steam turbine.

In regards to the request for the engagement of independent experts, Enemalta said it has sufficient in-house expertise to properly supervise the reliability and performance tests of the new plant.