Enemalta was supposed to take over the Delimara power station extension in June but technical hitches have delayed the transfer process, which has translated into daily fines.
The state-owned energy company said the plant will be formally handed over next month after a final round of testing.
The Government set the June deadline earlier this year.
However, a company spokeswoman said despite the delay, the extension was still producing electricity throughout the testing period, which had allowed the firm to switch off half the old Marsa plant.
Enemalta must shut down Marsa after an EU-imposed, 20,000-hour limit on operations ran out this year.
The company was fined €150,000 by the Malta Environment and Planning Authority for breaching the limit and is incurring a daily fine of €428 for each of the three expired plants.
It will be completely shut down when the interconnector cable with Sicily comes on board next year.
In these circumstances the Delimara extension is a crucial cog in the energy landscape, but sources have told The Sunday Times that various problems have beset the exhaust filtering system.
This is a prototype technology when used with diesel engines running on heavy fuel oil.
Enemalta said the problems encountered were normal during testing and commissioning.
“The problems were relatively minor issues.
“However, they required investigation and replacement of component parts, a process that takes time,” the spokeswoman said.
Enemalta wanted to ensure rigorous verifications were carried out, she said, adding the energy company would only take over the extension when it was satisfied with the test results.
In June, The Times had highlighted a problem with the filter bags used in the abatement mechanism that were damaged during test runs.
The dust filter bags were meant to last two years.
At the time Enemalta played down the problem, insisting only a very small proportion of filter bags were damaged.
Testing has now shifted to “a reliability run” that started earlier this month and the company is expecting to take over the facility in October.
The multi-million Delimara extension project has been mired in controversy after the tender was awarded to Danish company BWSC in 2009.
The Government was criticised for choosing a plant that ran on heavy fuel oil instead of gas, a cleaner fuel.
It meant the plant had to be equipped with a filtering mechanism untried on diesel engines to meet EU pollution limits.
But as Enemalta waits to take over the plant from BWSC, the Government earlier this month published a tender for a detailed analysis to convert the Delimara power station to natural gas firing.
Interested companies have until the end of October to submit their bid which must include detailed technical specifications for the conversion.
ksansone@timesofmalta.com