Objective
The aim of the project is to demonstrate the insertion of a small hydro installation in an irrigation system which is being renovated. A two wheel Francis turbine is being used to accommodate the variable flows.
From the technical point of view, in spite of the minor problems met with at the start of operations, the project has been a success.
- The use of a Francis turbine with two runners presented no technical problems, switching from one runner in operation to two and vice versa being carried out automatically as a function of the available discharge. In addition, the system enabled the machine to give a better output efficiency over a wide range of discharges than would have been possible with a single runner.
Regulation of the turbined discharge by means of a programmable controller worked completely satisfactorily.
The installation of a system of remote monitoring by Minitel enabled the functioning of the plant to be followed and in particular gave rapid warning of any incidents that occurred. This means of operating led to a great decrease in the time that the power station was shut down, which increased its profitability.
The financial results of the first five months were very satisfactory and lead to believe that, unless there is a technical breakdown, the scheme will be profitable in the long term for the commune has undertaken the operation.
The service life of the works and equipment associated with the small hydroelectric power station is between twenty to twenty-five years for the machinery, and fifty years for the civil engineering works.
On the other hand, the period of repayment of the loans is fixed at fifteen years.
After the fifteenth year the financial charges will therefore drop considerably and the commune will then be able to earn a substantial profit.
This type of multi-purpose agricultural hydraulic scheme presents a number of advantages, and allows :
- participation in the energy saving policies politics of a country or region, by the installation of small-scale hydroelectric power stations,
- The financing of projects for setting up or extending irrigation schemes in moderate altitude mountainous regions. Irrigation projects, even though subsidised, are rarely profitable.
If such projects are not undertaken, farmers gradually leave the profession and the mountainous areas become uncultivated and depopulated.
In France and abroad there are a number of such schemes which could be undertaken, provided that the regulations governing the diversion of water from mountain torrents do not become stricter than at present, and that the conditions under which electricity is bought do not become more unfavourable than at present.
The experience gained shows that the integration of small hydroelectric power stations into sprinkler irrigation schemes does not present any major technical problems, either in the design or running of the works.
It is therefore to be hoped that schemes such as the small power station at Benevent-Charbillac can be repeated and promoted.
The existing canal is being replaced by a 2. 4 km headwater channel which leads to a penstock supply tank, linked in turn to the 1.
7 km, 700 mm diameter penstock as well as the pressure feed irrigation network.
The hydro plant consists of a two wheel Francis turbine with a sliding gate, so that at flows of less than half of the nominal flow, only one of the wheels is used. The net head at the plant is 110 meters and the nominal flow 7 cums, giving a power output at the generator of 750 kW. The plant also has remote control using a programmable system. The sales of electricity to the grid are expected to generate revenues giving a simple payback on the initial investment of about 8 years.
Topic(s)
Data not availableCall for proposal
Data not availableFunding Scheme
DEM - Demonstration contractsCoordinator
13603 Aix-en-Provence
France