Run-of-River Hydro » How it works

Equipment

The main generating equipment comprises the following:

  • Turbine, to convert the potential of the abstracted water into a mechanical rotational energy
  • Generator, transforming the mechanical rotation to electrical energy
  • Transformer, increasing the electrical voltage to that of the National Grid
  • Control Panel, safely governing the entire generation process.

Hydro power is a global industry with much international competition. The resulting technological advancement means that reliability is now extremely high and maintenance straightforward. Most repairs are within the capability of local engineers.

There are many types of turbine with different designs of each. The speed, operating conditions and head must be taken into account when choosing the turbine that will give maximum benefit. Turbine design is now largely standardised and there is relatively little room to improve efficiencies, which often reach and sometimes exceed 90%.

The generator market has changed considerably over the past 30 years because of greatly increased demand for the type of machine suited to hydro schemes. The same type of generator may be used in many schemes - a trend that has brought costs down. Unlike the generator, the turbine must be chosen to suit the requirements of a particular project.

A major area of technological development is in power station control systems. The river flow present at any time is interpreted to determine how much water may be abstracted. The turbine inlet valves and hence the power output of the generating system are set accordingly. Schemes operate automatically and their performance can be monitored by remote telemetry.

We ensure that prudent safety measures are implemented within all projects. Equipment must be 'fail-safe', i.e. generation must cease in the event of a system malfunction. The remote telemetry link informs the maintenance services of the reason for shutdown so that early remedial action may be taken. In a well-engineered and maintained scheme, over 98% of the potential annual output should be extracted.

Depending on the location of the powerhouse and the outside air temperature, both ventilation and sound proofing may be required. Specially adapted air vents achieve this. Double doors and an insulated roof are common methods of dealing with noise pollution.