BWSC conversion to natural gas will take 12 months

The full conversion to gas of the D3 plant – better known as the BWSC plant – will take 12 months, informed sources have told MaltaToday.

Whilst Enemalta has failed to provide a timeframe in reply to questions by this newspaper, the energy supplier confirmed that only four engines will initially be converted to Wärtsilä 50DF dual fuel. This, it added, would provide the engines flexibility to run on gasoil.

“Once the re-build of these four engines is completed, the other four engines will be converted to natural gas as well. The two-stage approach is being adopted to ensure that Enemalta retains the necessary flexibility and security of supply to meet the country’s electricity requirements,” a spokesperson for Enemalta said.

The D3 power plant was sold to Chinese-state owned company Shanghai Electric Power for €150 million, with an additional investment of €70 million to convert it to gas.

News of the initiation of works for the conversion of the D3 plant was given by Prime Minister Joseph Muscat on Sunday while addressing a political activity. Muscat said that the use of heavy fuel oil was gradually being phased out and replaced by gas.

The Electrogas power plant, a 200MW plant running on LNG, is expected to be up and running by summer, according to minister Konrad Mizzi, but the plant has already missed a June 2016 deadline – a second missed deadline.

Enemalta plc is coordinating the complete elimination of heavy fuel oil (HFO) from the electricity generation mix. The new mix will be based on gas-fired plants, the Malta-Italy Interconnector and renewable energy sources.

A recent report from Standard & Poor’s has also noted that Malta’s power demand will be “partly sourced” from the interconnector with “the remainder” being acquired from Electrogas’s natural gas plant and SEP’s D3 plant.

Works on the conversion of the existing HFO-fired D3 plant started in 2014 and involves “extensive changes” to the existing Wärtsilä 18V46 diesel engines as well as other related installations.

“All engines will be converted to run on natural gas in two stages,” Enemalta said, having now finalised plans, safety reports and contracting. D3 Power Generation Company Ltd – where Enemalta holds a 10% shareholding, the rest held by Shanghai Power Electric – also consulted Enemalta’s capacity and planning dispatch section to finalise the isolation and conversion schedules.

Enemalta said that the conversion of each engine was a complex process involving the removal of all cylinder heads and cylinder liners, re-boring the engine block to accommodate the wider diameter of the new pistons, modification of the turbo chargers and refitting the engine with new pistons and cylinder heads. 

The existing mechanical fuel supply control system would need to be replaced with a plc-ignition control system to suit the requirements of the new fuel. 

All HFO fuel pipes and pumps would also need to be replaced with appropriate natural gas infrastructure. 

Finally, the engine compartment will be upgraded to introduce all necessary safety measures, whilst the emissions abatement system will be modified to suit the requirements of the new fuel and to do away with equipment specifically related to the use of HFO.

“The D3 plant will be supplied from the new LNG regasification facilities currently being developed by Electrogas Malta Ltd,” Enemalta said.