The Secret Diet of Air

Did you know that air can actually eat holes in the turbine blades of our hydro generators? It takes about 130 cubic metres of water per second to produce power at our Whitehorse hydro facility. Over time, the air bubbles in all that water can pit the metal blades. In some cases the pits can be a couple of centimetres deep!

That's one of the things we look for when we do annual or multi-year overhauls of the units. While they are shut down, we take advantage of them being off-line to test all the alarms, change filters, oil, and do other preventative maintenance.

We recently did this work on our largest hydro unit, known as the Fourth Wheel. We needed almost 73 kilograms (160 pounds) of welding material to fix the pits in the blades!  Each blade is close to four meters long.

Inside the area where the turbine is housed. Notice the pitting above the employees' heads.

Close up of some of the pitting