Sterblue Blog


Sterblue in Hong-Kong !

Article first published on October 2nd, 2018.

Sterblue officially reached its third continent! After Europe and Africa, Sterblue inspected its first asian electrical grids in Hong-Kong. I am just returning from a 5 days trip in Hong-Kong to meet CLP (China Light and Power), the local utility company.

Hong-Kong, damaged by typhoon Mangkhut

Hong-Kong is a 7.3 million inhabitants territory with almost 16 000 km of electrical power lines. The city is subject to typhoons during the summer and, this September, Hong-Kong was hit by Mangkhut, the strongest typhoon since Typhoon Ellen in 1983!

21 000 houses were out of power in Macau, but no power shortage were reported in Hong-Kong. The damages were colossal, but CLP managed to keep its grid safe. Hong-Kong has one of the most reliable power grids in the world.

CLP, a Free Electrons encounter

Sterblue met CLP during the 2018 edition of the Free Electrons program. Seduced by the idea of automatic inspections of their electrical transport grid, they asked Sterblue to come to Hong-Kong in order to train some of their pilots.

China Light and Power team with Hugo from Sterblue in Hong Kong
The CLP team and myself

CLP wants the best solutions to keep its structures in good condition. Using drones to inspect high voltage pylons and artificial intelligence to automatically detect defects on their structures is the solution CLP needs to monitor its grid’s health and prevent damages before it’s too late.

What did Sterblue do for CLP?

Sterblue’s solution consists of two parts. First, 3D flight plans are automatically created to accomplish the inspection of the infrastructures. The operator just needs to press a button in our app and let the drone fly automatically around structures.

Once the drone has inspected the structures, the drone operator simply uploads the pictures to our Cloud, where they are automatically treated. The images are analysed by a neural network trained to detect defects such as corrosion or broken equipment. A report is then automatically created, providing a clear summary of the health of the inspected structures and details about every anomaly found.

Lidar data from CLP lines integrated to Sterblue Cloud
Lidar data from CLP lines integrated to Sterblue Cloud

As CLP wanted to try this process on their electrical transport pylons, we asked them to provide us with some data about their network (KML or Lidar). With that information, we can recreate the topology of their network and model their pylons in our database. Our software then creates 3D flight paths around their structures avoiding surrounding obstacles, in this case: vegetation.

Trees, trees and… more trees !

The difficulty of the mission in Hong-Kong was the vegetation. Unlike most pylons we inspected so far, Hong-Kong’s ones were surrounded by a lot of trees. Until now, we mainly inspected pylons situated in open fields or where the surrounding vegetation was trimmed. Here, it was quite different!

First, to get to the pylons, you needed to climb over fallen trees. The forest was really damaged by the typhoon, making it hard to navigate through.

A CLP employee stepping over a fallen tree in Hong Kong
A CLP employee stepping over a fallen tree

After searching for a few minutes, we magically saw a clearance through the leaves, giving us a direct view on the pylon to inspect.

Transmission grid landscape in Hong Kong view from leaves
A small window between leaves

It was quite a relief to put down all our equipment. Even if the drone is not heavy, progressing through the vegetation under the warm and wet conditions was exhausting. Thankfully drone operations can be done remotely. If we had to go to the base of every pylon we inspected to proceed to a visual inspection, it would have taken us hours just to go from one pylon to another.

Once in position, Sterblue’s magic operates. The pilot just presses a button and the drone inspects the pylon. He can monitor everything via our application while resting from our trip through the jungle. Philip inspected 2 pylons from this location and then we continued our way through the vegetation to inspect more pylons.

Fortunately, we got some support from the local “Good Boy”, who welcomed us with a warm woof.

Dog in Hong Kong in the nature near power lines
The local dog greeting us


  • Sterblue’s solution performed very well in a complex environment.
  • We proceeded to the inspections of several pylons but, more importantly, I trained a Hong-Kongese pilot to do it without Sterblue’s help !
  • As at Sterblue we are perfectionists, we’ve taken note of the difficulties of inspections in the jungle and we are already working on making them easier.


Here is a nice picture of a pylon with Hong-Kong in the background:

Drone picture from transmission tower inspection by Sterblue in Hong Kong
A picture taken during an inspection, with Hong-Kong in background

And an example image captured that day:

Drone picture by Sterblue from insulators in transmission grid
A detailed view of insulators