Dear Musthafa,

The hydro power input to the turbine is given by

hydro Power input = Head x Flow x Gravity

where Power in Watts, head is in meters, flow of water in litres per second, gravity = 9.81.

The manufacturer should give you the efficiency of the machine, I mean combined efficiency of the turbine and the generator.

Then the electrical power output = efficiency x the hydro power input.

The other method is take a known rated electrical load and connect it to the generator with watt, volt and current meters. Increase the flow of the water until you read the rated power in the load. Find the hydro power input using the above relation. You know output and the input powers. Find the efficiency and compare with device data.

Or the simplest method. Ask the supplier a commission test and follow compare what they come out with the above methods.

You may read 'Calculating the amount of available power' at https://en.wikipedia.org/wiki/Hydropower 

You may read 'Calculating the amount of available power' at https://en.wikipedia.org/wiki/Hydropower 

Dear Kumar and Kannan,

Thanks for your answers. Now I am asking the suppliers to offer field efficiency test and model test. I should be deciding afterwards which one to apply. I think considering only the efficency, the key parameter for decision will be  the level of accuracy of the efficiency test. In fact  I submitted this question as a general question too.

@Mustafa

the questions should be:

are the tests conducted by the manufacturers reliable or not ?

how verify the reliability of their tests (measurement equipment and test protocol) ?

I support Mr. Bacetti Abdelmoumen. Being a research engineer involved in turbine design, manufacturing and laboratory testing. I would suggest you to check the used equipments there arrangements and callibration and cross measurement readings to ensure rhe reliability of test result. Also, in my view you should check laboratory test result than field test since it justifies almost all the operating conditions.

Dear Musthafa,

There are various methods for water flow measurement like by Propeller Current Meters, Acoustic Doppler Current Profiler, Ultrasonic Transit Time Flow meters....and so on.

Head may be measured by Pressure Sensors or level sensors.

For Efficiency calculation for different types of water turbines and other methods of measurement you can refer IEC 60041.

Both model test before manufacturing and running efficiency test after commissioning may be required. But generally Model test report carried out previously solve the purpose and for field efficiency test you can ask .

You may refer below link for efficiency measurement:

http://www.iitr.ac.in/departments/AH/uploads/File/Performance_testing_brochure.pdf

With Regards

Sasank Patnaik

IEC 60041 is for site testing, if we are talking about testing different kinds of turbines in one facility then it is the laboratory testing. There could be two techniques for this;

1. IEC 60193 : to be used for model testing. 

2. Proper arrangements of all the sensors as per the description by the manufacturer, updated calibration of all of them and cross reading of them. This system is usually used for Micro Hydro Turbine Testing. Usually small prototype turbines can be tested with this methodology. 

Model test and Power Output Verification both are very important actually. 

@Ravi Koirala

To be honest, I don't know if we should trust suppliers and manufacturers test results.

I don't know any manufacturer who is ready to negatively assess his product especially after the delivery.

Actually, I won't be paranoiac but the clients should ask a third party to conduct the tests and they should ask the use of test equipment/protocols made/established according to some standard.

Otherwise, I think it would be better to just believe the manufacturer and save the money we intend to spend on tests.