Hongkongers are being asked to pick one of two proposals for the city's future power supply.
One option is to import 50 per cent of our electricity from mainland China; the rest will be generated locally - 40 per cent using natural gas and 10 per cent from coal.
Option two is for 60 per cent of energy to be locally produced by natural gas, and 20 per cent created here by coal; only 20 per cent will come from the mainland.
The government backs the first option, but close scrutiny has raised questions about how suitable it is. Members of Hong Kong's professional mechanical engineering community held a forum to discuss the topic. Two concerns are worth sharing here.
One concern is reliability. Hong Kong's success depends on its high density of electric-powered devices functioning at very high level, such as lifts and escalators, advanced telecommunications and computer-based trading systems.
Imagine what would happen if we suddenly had no power. How would people living in tall apartment blocks cope with getting to school or work? How would businesses be able to function?
For decades, Hong Kong's power companies have provided reliable electricity across the territory. But mainland power company standards are not as high. So there may be a risk if we expose Hong Kong to the uncertainty of power coming from the mainland.
Another fear is for the environment. Electricity from the mainland may cut emissions created in Hong Kong, but emissions will still be created in the Pearl River Delta. What's more, we will not know what fuel source generated the electricity, or how clean production was.
As there are no barriers in the air, if the power were created from a less clean source, such as coal, it would pollute our city just as much as if the coal was burned here.
If generating electricity in the Delta doesn't cause substantial reductions of carbon intensity or emissions, there is no environmental advantage to option one.