FUEL SUPPLY FOR POWER STATIONS

FUEL SUPPLY FOR POWER STATIONS

8.

Dr Ong Seh Hong asked the Minister for Trade and Industry (a) whether he agrees that having one source of fuel supply for several power stations will make us very vulnerable to power failures as indicated during the recent power failures; (b) what can be done to solve the problem; (c) why does it take so long, in some instances about three hours, to switch to an alternative fuel supply; (d) given the damage that it will cause to Singapore's reputation, what, if any, strategic plans his Ministry has to ensure that there is uninterrupted power supply not dissimilar to our water supply.

BG George Yong-Boon Yeo: Our power stations are not dependent on just one fuel type. In fact, the gas plants are required to have a dual-fuel design feature, and are able to quickly switch to diesel in the event of a gas disruption.

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The gas plants have the capability to switch to diesel, without turning off the turbines. This allows them to "hotswitch" seamlessly to an alternative fuel in the event of a gas disruption, without cutting electricity supply. The switching takes time to execute and has to be done before the gas in the pipelines runs out. The residual gas in the pipeline typically runs out in about 10 minutes, depending on the physical location of the shutdown and the rate at which gas is being drawn.

If the gas runs out before the plants successfully hotswitch, the gas turbines would trip and would take about one and a half hours to restart with diesel. This will lead to a temporary loss of power and cause a blackout. Power restoration takes time as supply and demand have to be kept in balance at all times. After each area is restored, the system has to be allowed to stabilise before restoration continues. For the power failure on 29th June 2004 , full system recovery was achieved in about one hour and 50 minutes.

Energy security is a prime consideration for us as having reliable and competitive electricity supply is vital. Today, we are in a strong energy supply position. The installed generation capacity comprises a good balance of fuel types, with 60% capacity in oil-fired steam plants and 40% in gas plants. Our electricity market has excess capacity. The power stations are also required to stockpile at least 90 days worth of fuel reserves in the event of supply disruption, with 45 days storage on site.

Even in the event of a prolonged disruption in gas supply, our energy security will not be compromised. However, if we switch to oil-fired steam plants, or run the gas plants on diesel, there will be a cost impact as the price of electricity from oil and diesel will be 10% to 20% higher than gas.

Further measures are being taken to improve system robustness. EMA is working with the power stations to build gas supply redundancy into their operations so that they have access to gas from at least two separate sources to reduce their vulnerability to a gas disruption from one pipeline. Senoko Power already has two pipelines feeding into its station. PowerSeraya is commissioning its second pipeline. Tuas Power plans to have its second pipeline by mid 2005. Engineering studies are being done to work out how one pipeline can seamlessly support the other if it fails. The back-up pipeline will give power stations more time to switch from gas to diesel and make the system more robust.

EMA is also studying the viability of a liquefied natural gas (LNG) facility. From the security perspective, the facility will open access to natural gas from anywhere in the world and will provide LNG stockpile. EMA is finalising the tender specifications for a feasibility study, which will be called in July 2004. If approved, the LNG facility should be operational after 2010.

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