[Manila-X]

When was the last time you have experienced a blackout in HK? Growing up here I rarely experienced that except there were a few areas that have a brief schedule for a temporary blackout say an hour. Even during a strong typhoon, HK didn't have a major blackout problem.

The city's electricity primarily runs underground though overhead wires can be found in some areas with The New Territories and Outlying Islands.

What do you think?

 

[superchan7]

The last Signal 8 typhoon was my last blackout, but I live out in the villages where exposed power lines are especially vulnerable.

 

[Scion]

HK rarely have blackouts, mainly due to the fact that a lot of the power lines are lay underground, and not on telegraph poles.

 

[EricIsHim]

There has been district or neighbourhood wide black-out due to blow out of the substations locally. But this only affect small area.

As everyone said, underground infrastructures helps a lot. But high voltage cross city wires are still overhead hang between towers you see up on the mountains. They are the actual backbone that feeds electricity into the underground wires. They do are designed to withstand super typhoon force prevent damaging.

The other system to prevent black out is the CLP and HK Electric systems are interconnected. If there is a big failure for either provider, the other one can kick in to supply electricity outside original service area immediately.

 

[hkskyline]

^ That can also be a weakness, as seen in the great blackout in the Northeast a few years ago. One fault rippled through to several states and across to Canada.

 

[EricIsHim]

^ That can also be a weakness, as seen in the great blackout in the Northeast a few years ago. One fault rippled through to several states and across to Canada.

Nope. The northeast (of North America, for those who don't know where we are talking about) has a different power system then HK.

The northeast has the power grid interconnected to aid the demand and supple balancing. If there is a certain areas and times require a large demand of power (like during the summer when a/c is popular), but the local power plant can't supply so much. The system will draw power from others to fill in the need. Or if there is an excess of supply in certain location, it will send the excess to somewhere it needs and reduce the power generated. In other word, the system also help to reduce the amount of waste electric energy generated which can't be recycled. The pros are it help to balance supply and demand, as well as better generation management. The cons are, as we had seen, since the all the power plants are interconnected in a grid as series, once one line fails, everyone else goes down at the same time.

The interconnection in HK are mainly for emergency purpose only, and have minimum transfer over electricity to control the supply/demand or optimize use of resources. On a day to day basis, CLP and HK Electric doesn't transfer any electricity between each other. HKI and Lamma use HK Electric generated power exclusively; all other locations uses CLP generated power. So if CLP failed, HKI and Lamma will still have electricity, but not in Kowloon, NT and other outlying islands. In such case, the interconnect will kick in and HK Electric will start transfer electricity across the harbour providing service in CLP's service area. So that the black-out situation won't happen.

In addition, HK Electric has transferred some its overhead high voltage wires over the mountains and country parks between south of HKI and north of HKI down inside the four underground tunnels instead as well.

 

[hkskyline]

Although the transfers may not happen between utilities, the fact that they share the grid means that even though no electricity is going between them, if a fault happens somewhere and ripples out, then the other utility will still be impacted.

I don't think Ohio was exporting or importing electricity from all of the states / provinces that got hit by the great blackout. It just so happens that they were all on the same network.

I liken it to a car accident on the highway. Everyone else behind the site has to slow down even though they are not involved in the crash.

Or are such ripples not possible unless there is live electricity running on those wires, meaning it is not a capacity issue (wires exist hence problems ripple through even if they are not used), but rather a demand issue (problems can only ripple through wires carrying power).

 

[EricIsHim]

I don't think an active wire will have an effect on an inactive connection if there is anything bad happens. It is just not an available passage.

I guess you can think of it as a closed roadway which will not be affected by the ripple effect on the mainline in terms of transportation.