Introduction: What are Singapore’s energy sources?
Approximately 95% of Singapore’s electricity is produced from natural gas (Fig. 1). Other sources of energy for generating electricity include coal, petroleum products (e.g. diesel, fuel oil) and other energy products.[i] While natural gas is considered the cleanest form of energy source in terms of CO2/MWh, Singapore continues to use other energy sources due to commercial reasons and to ensure energy security.
Traditionally, most of Singapore’s supply of natural gas comes from pipelines connected to Indonesia and Malaysia. This is known as Piped Natural Gas (PNG), which is supplied from the Natuna Gas Field (East Malaysian Sea) and the Grissik Gas Field.
In recent years, liquid natural gas (LNG) has started to play a bigger role in power generation. In 2013, the LNG Terminal was constructed to import, store, and re-export LNG to the region[i] (see Box 1).
The LNG Terminal was built to diversify Singapore’s energy sources, reducing its dependence on Malaysia and Indonesia for imports of natural gas, and increase its energy security.
To support the uptake of LNG, the Singapore Government has introduced measures to restrict the import of PNG. In addition, the Singapore Exchange (SGX) and Energy Market Company jointly developed the SGX LNG Index to encourage price discovery and improved transparency for LNG trading in the region.
Alternatives sources of energy: solar
Besides generating electricity through conventional methods (combustion), the Government has started to explore alternative means of energy generation and management. Solar energy stands out as the energy source with the greatest potential for deployment in Singapore’s context. Singapore receives sunshine all year-round, with an average solar irradiance of 1580kWh/m2/year (or, 50% more solar radiation compared to temperate countries).[ii]
While solar energy is typically generated and consumed on-site, a number of energy players in Singapore have emerged recently to supply off-site solar energy to consumers who may have insufficient rooftop space. This usually requires a method to track solar generation and consumption. Companies that provide such services include Sun Electric and Sunseap Energy.
[ii] “Solar Photovolatic Systems,” Energy Market Authority. https://www.ema.gov.sg/Solar_Photovoltaic_Systems.aspx
What types of technology are used for electricity generation?
Combined-Cycle Gas Turbine
The most commonly utilised generation technology in Singapore is known as a combined-cycle gas turbine (CCGT) plant. As opposed to a normal gas turbine, CCGT plants are more efficient, allowing more energy to be extracted through two combined cycles, a gas turbine cycle and a steam turbine cycle (see Box 2).
Cogeneration and Trigeneration Steam produced from a CCGT still contains a valuable amount of energy that can be further extracted. Exhaust steam from CCGTs is commonly supplied to industrial users in the vicinity of the power plant. Some companies make use of this excess steam as part of their manufacturing process. In addition to that, excess steam from power plants can also be used to produce chilled water through an absorption cooling/chilling process. Chilled water can either be used for industrial purposes.
Box 2: How a CCGT works
In a CCGT, natural gas undergoes combustion and passes through a high-temperature set of gas turbines, which in turns creates a rotational motion. This motion, when connected to an alternator, generates AC power. The hot gas that is expelled from the gas turbine is then run through a heat recovery steam generator, essentially a heat exchanger, turning water into steam in the process. This steam is used to power a steam turbine, which works in a similar way to a gas turbine, only at lower temperatures and pressures. The steam that exits the steam turbine can be further used for industrial applications.