The Taltson Hydro Plant

Eloise McMinn Mitchell, Flyability 

Analysing a 35m dam surge tank using a drone in Canada

HYDROELECTRIC power is a highly scrutinised industry. The infrastructure is built with the best technology of the day. However, technology is constantly developing. Over time, it is necessary to go back to the hydroelectric plant and update it, and where possible, upgrade the plant output.

Taltson Hydro Plant is situated on the Taltson River, a 290m long waterway in the Northwest Territory of Canada. Currently, it has one hydroelectric power station. The station has been taken offline for six months to enable refurbishment. It will be overhauled, including installing a new turbine, a new generator and as-needed repair work.

Planning future hydroelectric plant upgrades with drone mapping

Hydroelectric power is a highly scrutinised industry. The infrastructure is built with the best technology of the day. 

Part of the expansive operations for the Taltson Hydro Plant’s refurbishment include the turbine being upgraded as well as the generator to increase the maximum capacity of the plant.

This includes inspecting all aspects of the water conveyance system with particular focus on the penstock surge tank to understand its flow capacity and condition.

This is a critical element as it is used as a damper during the normal operation of the turbine. Data collection to assess the condition of assets would also be critical to this process. The hydro plant would need to be digitised to help assess and plan these upgrades to the plant.

Of particular interest was the surge tank, which reaches 35m high. By using drones, the best means of accessing any necessary work at height could be planned.

Drones in inspection workflows

The site, which is incredibly remote with access only possible by a small plane, rather than roads, needed to have visual inspections completed as well as lidar imagery.

The Elios 3 was selected to safely collect data at height and inside the confined spaces of penstocks, tunnels, and the surge tank.

The orifice of the surge tower and a move further inside the penstock with the drone was highlighted for particular interest.

With this all planned, the drone flight, which took just seven minutes, collected all of the necessary data in the 35m high surge tank.

Afterwards, the drone was flown further into the structure, analysing the T-joint in the piping and tunnels, alongside visual imagery and lidar data collection.

Surge tank inspection

The data from the flight with the Elios 3 was used to extract a 3D scan. This was then used to perform computational fluid dynamics (CFD) analysis on the orifice and tee joint losses for the future operation of the surge tank.

Access for the rope engineers to conduct this was planned from the drone inspection. This was vital as it found that some structures in the tank that had been intended to be use to secure the ropes had rusted.

Access for the rope engineers to conduct this was planned from the drone inspection. This was vital as it found that some structures in the tank that had been intended to be used to secure the ropes had rusted. There were also missing bolts and screws.

In addition, it found that the T-joint had been built differently from the as-planned records, which was important information to confirm the maximum pressure capacity of the penstock with the new installations.

Impact of a drone inspection

The work done highlighted how rope teams can work in partnership with drone inspections to enable safer and more efficient operations.

In addition to this, more information than expected was able to be provided to help streamline the refurbishment process.

The Taltson Hydro Plant will now soon be online with the new unit, and ready to supply the local community. Steps are also being taken for a future upgrade to a 22MW site from 18MW. 

Eloise McMinn Mitchell, Flyability

www.flyability.com

All images courtesy of Flyability.