SINGAPORE - Exxonmobil said on Thursday that it has started the construction of a new 84-megawatt cogeneration plant at its Singapore refinery's Jurong site.

The plant will increase the energy efficiency of the refinery upon completion.

Cogeneration is the simultaneous production of electricity and steam from a single fuel source.

When the latest cogeneration facility is completed in 2017, ExxonMobil will have more than 440 megawatts of capacity in Singapore.

The company currently has 360-megawatt cogeneration capacity at its integrated refining and petrochemical complex, which currently meets all of its internal power needs on Jurong Island.

The electricity produced by its new cogeneration facility will produce enough electricity to power the equivalent of 150,000 four-room Housing and Development Board flats in Singapore, based on 2014 average household electricity consumption data.

The cogeneration facility, which will use clean burning natural gas, will also produce steam which is utilized by the refinery. The concurrent steam production will enable the shutdown of two older less efficient boilers. It will in turn reduce emissions and result in a reduction of 140 kilotons per year of carbon dioxide emissions. This carbon dioxide emissions reduction is equivalent to taking more than 45,000 cars off the roads of Singapore.

Singapore Economic Development Board director of the energy and chemicals sector Eugene Leong said: "ExxonMobil's cogeneration project brings significant benefits for both the industry and the environment, with the reduction of emissions and energy costs."

"Investments that strengthen the foundation of our industry are as important as green-field investments, as they set the stage for companies to pursue long term sustainable growth. It is important for Singapore that companies like ExxonMobil continue to invest in the long-term competitiveness of their operating facilities here," he noted.