Two modifications for gas-driven plants are starting out in the region
Matthew Phan, Business Times 28 Mar 08;
ASIAN utilities and other energy users are showing keen interest in improving efficiency and recycling waste gases in their generators, says an executive of US-based GE Energy.
The power generating plant maker's regional director of strategic marketing S Ramanan said that two particular modifications for gas-driven power plants are 'just starting out' in Asia but could rapidly catch on.
The first is fuel flexibility, which allows generators to burn a blend of waste gas and natural gas. The second is operating flexibility, which raises the efficiency of gas turbines even when they are running at low, off-peak utilisation rates.
Fuel-flex technology was developed decades ago and is widespread in the US and North Asia - which have had to import natural gas - but not in South-east Asia, Mr Ramanan said.
Blends can comprise a significant portion - or even a majority - of waste gas. Given that the cost of fuel makes up 60-70 per cent of the cost of power generation, fuel flexibility is 'critical for Singapore to consider' as it is highly dependent on natural gas, he said.
Fuel-flex is used ideally where infrastructure already exists, such as on Jurong Island, Mr Ramanan said.
Elsewhere, GE has booked projects in Thailand, Malaysia and Australia.
The challenge with fuel-flex is that a lot of infrastructure is required to collect and compress the waste gas - large quantities are needed because the gas has relatively low calorie content and is released at low pressure.
Ironically, it tends to be older generation turbines, like GE's E-class turbines, that can burn different fuels, Mr Ramanan said.
With E-class turbines, when gas first contacts the turbines - which is where heat is converted to mechanical energy - its temperature is 1,100 to 1,200 degrees Celsius, versus 1,300 to 1,500 degrees for its F-class turbines.
The lower burning temperature allows E-class turbines to use different fuel mixes; though if they use natural gas alone, they run at a lower efficiency than F-class units.
Op-flex, meanwhile, is a relatively new technology, developed in response to higher energy prices, as generators turn their gas turbines on and off more often to cut waste.
Again, it is more widespread in the US and North Asia, where gas turbines are used as necessary to meet peak demand, rather than in South-east Asia, where gas is burned for base-load power.
PowerSeraya told BT that it does not use fuel-flex or op-flex technology at its plants, which it manages based on peak and off-peak needs.
Tuas Power and Senoko Power did not respond to queries by press time.
