TGVHydro specialise in high-head systems that generate electricity by capturing the energy from a relatively small amount of water but falling over a large height (the head). No two schemes are alike but we will typically work on systems where there is at least of 20m head, from the intake to the turbine house, and enough flow to generate at least 5kW of power. (See the Guide to Microhydro to estimate the potential power in a system).
TGVHydro’s systems have four key components. An intake which diverts an approved proportion of the flow out of the stream; the pipe which transfers that water down the hillside and will normally be buried in the ground; the turbine which converts the kinetic energy of the water into electricity; and a converter which adjusts the voltage and phase for export into the grid.
A typical intake is a small steel weir with a grid capturing the flow from the stream.
One of two intakes for a domestic 7kW scheme.
The intake for a 12kW farm scheme.
The pipe is a tough, thick walled PE pipe capable of withstanding high operating pressures – sometimes up to 20 atmospheres.
The turbine and controller
The turbine and controller are typically housed in a small outbuilding or shed.
A 7kW turbine and generator in the turbine house.
The control unit is mounted on the wall of the turbine house.
Detail of a 7kW Hydrolite turbine showing the electronically controlled spear valve to control the flow of water onto the turgo runner. Special thanks to Rob Sotgiu of Hydrolite for this gorgeous photograph.