Water mill of Sainte Rose offers an energy potential that may allow its own autonomy and much more.
Arrats river, 4th river of Gers area has an average rate of 2.7 m3/sec (16bbls/s). This opens a possibility to use a water fall of 2 to 2.5m (7 to 9 ft) on this site.

The matter is not to use all of the flow rate (Total potential 25Kw). In calculations, we consider very reasonable to consider 1m3/s (6bbls) for insuring a good regularity all along the seasons. These performances are very realistic without important modification of the plant.

Power reach 10kw if we consider thise preservative numbers. For personal use, a single turbine of 5kw power is more then sufficient knowing that we have no way for storage.

Choice of a turbine :

According possibilities of the owner, several types can be instaled. In any case, we have to take a turbine specific for small falls as : Dumont, Axial, bulbe, banki (Or cross flow).

You can find them brand new or used. One of these types can be manufactured by a good tecnician: Banki turbine (Or cross flow).

For a private use, I would prefer Banki solution because its cheap ,more simple to manufacture and also its quite easy to size them for Sainte Rose without big modifications of the site. (Project has been made for 2 turbines 5kw each.) But to stay far from head heaches, manufacturers can propose a big quantity of solutions sized for each case.

Sale of electric power :

In Gers region, most of production plants are on Baļse river as it offers a larger flow rate that gives more interesting comercial aspect
Price of a electricity regulation and transfer on EDF net (National energy company) is quite high is you compare to production possibility. This leads to the conclusion that Sainte Rose water mill is at the moment adapted for a private usage...also we have to know that EDF buys electricity quite sheap (more or less 6.1 cents of Euro / kw) . This increases difficulty for making a fast and good profit.
Due to the energy price evolution and a necessity to encourage substitutes to oil, a new study should be interesting, knowing that a family uses 4000 Kw/year and that 2 single 5 kw turbine produce 80000 kw/year.
At today“s date, private production is already an exelent option, but selling energy is a solution more atractive every day, and can be considered at long term.

Sainte Rose water mill, as most of the water mills has been forgotten and considered only for its historical value and a certain charm of the area. But due to its energical potential it will survive again and better , and will finaly come back to its historical activity : conversion of hydraulic energy.