Hong Kong

The Nethersole Hospital in Tai Po, Hong Kong is to use methane gas from landfill in a green energy pilot scheme to be launched later this year.

The project will cost HK$13 million and entails the use of a combined heat and power system. While it produces electricity, waste heat at a temperature of 500 degrees Celsius from the generator’s exhaust will go to a boiler to produce steam. Waste heat from generator cooling will also be used in a heat exchanger for hot-water supply.
Hong Kong
Unlike a conventional generating system, which only converts 40 per cent of the power it creates to electricity, the new cogeneration system uses another 40 per cent of generated power for thermal-energy supply, and releases the remaining 20 per cent as waste energy.

The methane – which will come from the Ta Kwu Ling landfill in the northeastern New Territories – provides a cheaper alternative fuel. Each unit of methane costs about 0.1 cents, in contrast to 0.15 cents per unit of gas.

“The new system will save the hospital around HK$2 million annually on fuel, which is 7 per cent of the energy expenditure,” said Yuen Pak-leung, senior manager of engineering for the Hospital Authority. “Methane has similar ingredients and heating value to natural gas. No exhaust fumes will be emitted from the combustion.”

The more efficient use of power would reduce the carbon emitted annually by the hospital by 2,000 tonnes, or 12 per cent.