Realization mechanism to make electricity.

[Dearcham]

Hello everyone, to have seen several small hydropower plants operating in recent months, I can confirm several things to you.

Their characteristic, in terms of power is not to exceed 10MW (threshold between small and large hydraulics). Small hydroelectric power stations commonly referred to as micro power plants run on the water, that is to say without a tank, without storage. They represent around 10% of French hydroelectric production. Their impact on the aquatic environment and on other uses of water (these rights are to be seen with the town hall and local fishermen's associations, it is often this administrative point that poses the most problem, it sometimes takes several years to obtain the right to water) are compensated by specific measures such as maintaining a level of a non-turbinated flow in the river bed (reserved flow) permanently guaranteeing life, circulation and reproduction fish species and the construction of devices allowing thresholds to be crossed by migratory fish.
The effectiveness of these measures involves certain equipment (notably speed control) but also appropriate management.

The economic impact of a small power plant, for a predominantly rural municipality where these installations are generally located, is far from negligible. A PCH can represent the most important activity in terms of tax revenue



The intake channel is the diversion channel of the stream which brings water to the mill.

The water intake is designed to divert the water necessary for the operation of the installation. It is composed of a spillway threshold which creates a small reservoir of water guaranteeing the supply of the transfer structure, a fish passage and the flow reserved to maintain the level of the watercourse. It also includes a field of protective grids against floating that a screen automatically comes to clean in order to avoid blocking the water inlet, a penstock isolation valve, a reservoir release valve and a sand trap that will trap the sands in suspension in the water and thus protect the turbine.

The transfer work or penstock is generally made of steel (but the wood is damn better: acacia is the wood that holds best underwater) and dimensioned so that it ensures the correct transit of the flow required to supply the turbines


The factory contains the hydromechanical and electrical elements allowing the production of electrical energy. Its operation can be schematized as follows: the water arriving by the penstock is directed towards the turbine (for small falls it is necessary to '' use a KAPLAN turbine) which converts hydraulic energy into mechanical energy. By its rotation, the turbine drives a generator converting mechanical energy into electrical energy. The smooth running of this set is ensured by an automaton which, depending on the flow present in the river intervenes on the hydraulic group controlling the supply of the turbine in order to optimize the power thereof.
The water, once passed through the turbine is returned to the stream through the leak channel.



The installations that I could see were all provided with a device located after the turbine allowing to accelerate the flow consisting in widening the outlet pipe with an incidence of 8%
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For more info call the EAF on 01 46 30 28 28
or contact ADERA in Haute Saone: an association which rebuilds a mill with youth work sites to make it a welcome center on renewable energies (they have an impressive number of contacts)
Ask Fabrice (Doudou for friends)