Hong Kong has to look for more sources of power from the mainland to help attain its emission-reduction goals, but substantial expansion of nuclear energy imports might be out of question in the short-term, according to a source close to the government.
An electricity-import option will be among proposals tabled in a public consultation process the Environment Bureau will start later this month.
Under that option, Hong Kong might in the long-term extend its connection to the Guangdong power grid or build dedicated power lines for direct electricity imports to reduce its reliance on coal burning.
Depending on the extent of reduction in coal burning in power generation and the availability of more nuclear energy, the electricity-import option could provide at least 10 per cent of the city's power needs, according to the source.
"Given the scale of the southern China grid, the import will be just be a drop in the ocean," he said, adding that the China Southern Power Grid, which included the Guangdong grid, sold some 800 billion kWh of energy a year, compared to about 40 billion consumed in Hong Kong.
The consultation exercise comes after the 2011 Fukushima nuclear crisis saw the government scrap an energy-mix proposal designed to address climate change. It had set an ambitious goal of cutting carbon emissions by 50 to 60 per cent by 2020.
That proposal would have meant more than doubling the nuclear share in the mix - currently 23 per cent - to 50 per cent, while the share of coal would have been slashed from the existing 54 to 10 per cent. The remaining 40 per cent was to have been natural gas.
The consultation document is expected to recommend several options with different combinations of gas, nuclear, coal, and renewables. The costs of these options reportedly did not vary significantly. The proposed mix will become the core of the city's energy policy, determining how far it can go in improving air quality and mitigating climate change.
But the source said Hong Kong faced a bottleneck in boosting its nuclear intake unless new reactors could be built.
The city now buys via CLP Power 70 per cent of the electricity output from two reactors in Daya Bay in Guangdong. CLP recently secured an agreement with Daya Bay to increase that to 80 per cent until 2018.
The source said Guangdong did not want to give up the remaining 20 per cent, as the province also needed the energy.
Dr Tso Che-wah, from City University's school of energy and environment, said Hong Kong should be content with the current nuclear energy level, as it was already significantly higher than the national average. "We can't be greedy and ask whatever we want from the mainland, as it also has emission targets to meet."
Tso also opposed a closer integration of power grids with Guangdong, saying this could destabilise Hong Kong's grid when there was a supply disruption across the border.
Dr Luk Bing-lam, chairman of the Hong Kong Nuclear Society, said importing power might not always be cheap if subsidies on the mainland were discontinued.
Luk also questioned how clean any imported energy would be. "How can we tell if the electricity we import is actually hydro, nuclear or coal?"
He suggested that Hong Kong could invest in new nuclear power stations of its own.