The final stage in the installation of a micro-hydro plant involves performance tests. The purpose is to check the function of the different components of the scheme and to measure the overall system performance against the figures arrived at during the design of the scheme.

Depending on the complexity of the system, it may take several months before all working conditions are experienced. Hence, although formal commissioning and hand-over may be completed in a few days, the end-user should not consider the job fully completed until satisfied that all operating conditions have been met.

Important activities during commissioning will include: 

• Ensuring sufficient flow is being drawn through the intake
• Confirming that the channel can pass the design flow without undue head loss
• Checking that surplus water passing through the intake will escape down the appropriate spillways and will never overflow the channel walls
• Confirming that the design flow will pass down the penstock without entraining air at the forebay
• Measuring the head loss in the penstock
• Checking the penstock joints for leaks
• Confirming the smooth running of the turbine and generator, including checking the bearings for noise and temperature
• Checking that belts and pulleys are correctly aligned, or that the gearbox is operating effectively without overheating
• Ensuring that the lubricating systems are working for the bearings and gearbox
• Confirming that the turbine achieves its design power at rated head and flow
• Checking all the functions of the control panel, in particular start-up and shut-down sequences plus all the switchgear which interface and protect the system from the grid