Revamped hydro power station could fill an Olympic pool in 30 seconds

In 2017, SSE began considering the future role of the Tummel power station including the possibility of replacing it entirely.

The full internal refurbishment is expected to secure its role in the energy mix for at least another three decades.

Computer aided designs have allowed engineers to increase the generating capacity by about 17% from the same volume of water passing through it.

Project manager David Gallacher says hydro-power plays a hugely important role.

He added: “We’ve made use of the existing infrastructure, so the dam, aqueduct system and the building itself all remained. We’ve modernised and upgraded where we can but it’s all stayed the same.”

While dozens of people have been working on the project over the last two years, once operational it will be controlled entirely remotely from SSE’s headquarters in Perth.

The company is looking at upgrading other hydro schemes in Scotland, including at Sloy on Loch Lomond.