FUEL-MIX FOR ELECTRICITY GENERATION
According to the IEA World Energy Outlook 2008, electricity generation is the largest source of global CO2 emission by sector. As electricity generation accounts for 67% of Hong Kong’s total GHG emissions in 2008, fuel-mix has a pivotal role in determining ourcarbon footprint.
In 2009, Hong Kong’s electricity generation fuel-mix is made up of 54% by coal, 23% by gas and 23% by nuclear. To tackle our carbon emissions, the Government proposed in a 2010 Consultation Document to increase nuclear power to 50%, natural gas to 40% andrenewable energy (RE)to 3-4%, but reduce coal to 6-7% by 2020.
RE is an emission free energy and its most popular forms are wind power and PV solar.Hong Kong’s scarcity of land with its hilly topographymakes it not feasible to develop land base wind farm.Its surrounding deep-water sea also poses huge challengeto build wind turbine offshore. As Hong Kong is located close to the Earth’s equator where wind resource is rather weak, the capacityfactor of wind farm is around 20%.Current design of solar PV system for electricity generation requires very large footprint. Even Hong Kong has relative abundant sunshine, PV systemcan achievecapacity factor of around 15%. Technically, sizable development of emission free RE at this stageis at best confined to offshore wind farm.
As nuclear energy for electricity generation has zero-carbon emissions, it has become a popular choice as a quick fix to reduce carbon footprints. Nuclear power is controversial and there is always concern over its safety since the Chernobyl disaster in 1986 andThe Three Mile Island accident in 1979. The Tohoku earthquake and tsunami in March 2011 seriously crippled the Fukushima Nuclear Power Plant has further reinforced such fear. The release of huge hazardous radioactive materials and discharge of highly radioactive waste watercaused severe damages to the environment, ecosystems and food chains.It is prudentnot to consider additional sources of imported nuclear power from the Mainland at this stage.Technically, Daya Bay Nuclear Power Plant can allocate more of its output capacity for Hong Kong such that nuclear power in its fuel-mix can increase to 28%.
Adoption of 3-4% by RE, 28% by nuclear power, 50% by natural gas and 18% by coalin the fuel-mix by 2020can reduce CO2 emission/kWh by 38% compared with 2009 level, based on specific CO2 emission of 0.38kg/kWh for gas-fired unit and 0.82kg/kWh for coal-fired unit.It is estimated that adoption of such fuel-mix will increase the cost of electricity by about 20%.The public has to be convinced thatit is worth paying more for green and reliable electricity.
Ir Dr C W Tso