How to acquire voltage/current data for testing solar cell?

[mikeg123]

As part of a senior design project at my college, my group and I have been assigned the task of building a solar cell tester. Basically this entails producing a light source that does a good job of simulating the sun, then acquiring voltage and current data from the solar cell and inputting it to a computer to develop a current-voltage curve. From here we will compute the efficiency of the solar cell.

The problem is, I am not quite sure how exactly to acquire this data from the cell. The cell has two leads coming from it, which can be used to measure voltage across a resistor. How can this be implemented into a data aquisition unit, and which product may be suitable for our needs? I appreciate any help.

Thanks.

[Coq_Rouge]

A few years ago i was looking for such a system. I found this in my archive http://www.pvmeas.com/index.html. If you ask them nice maybe they can give you push in the right direction. You will also need some voltage measuring devices. I guess you do not need high samplerates, but high precision. Perhaps you could interface your computer to some existing lab instrument via RS232 or GPIB. Or maybe use a daq card if your school have such device. All this may be a simple task in Labview. I could say more, but half the fun is the search for information part

[smercurio_fc]

From what you describe it does not sound like you are trying to perform a detailed characterization of a solar cell. If you're just looking to get the basic IV curve then all you need is a source (power supply) to provide a voltage and a way to measure the current (current meter). Most power supplies can do both, but you need to look to see what the measurement accuracy is of the power supply versus using an instrument that's specific to measuring.

I would suggest first doing some research on testing of solar cells so you know the basic procedure. Some factors that you will need to take into account is being able to control the light source so it's constant, and being able to control the temperature of the solar cell. As the cell heats up its characteristics will change, so you need to take that variable out of the equation. Usually this involves mounting it on a heatsink, and sometimes even chilling the heatsink. Then you can move on to determining what equipment you need (which isn't much), and then determining what you have available to you at your college lab. 

[J-M]

What is the accuracy do you need? An accurate solar cell tester is an expensive setup mainly because the price of the light source (http://www.sciencetech-inc.com/catalog/3/fully_reflective_solar_simulators in canadian dollars)? If you want an automated setup you need:

- a light source (including the solar filter – in general AM1.5 in North America);

- a calibrated solar cell or a thermopile to adjust the intensity of the light;

- a programmable electronic load (i.e Agilent 6060B or BK Precision 8500, 8510) or a good programmable DC power supply (in general it will do the job but it is not design for) – the solar cell is connected to the DC load;

- a thermocouple;

- a shunt or a hall effect current sensor;

- three analog input (one for the solar cell current, the second for the solar cell voltage and the third one for the thermocouple)

1) Adjust the light source at 1000W/m2;

2) Measure the temperature of the solar cell;

2) Measure the voltage at zero volt (I short circuit);

3) Send the command to the electronic load to increase the voltage step by step until the current is zero (Voltage open circuit) and at each step you plot I vs V and P vs V (or P vs I).

4) the maximum efficiency, at this temperature, is the maximum power divide by the power received by solar cell (effective surface x 1000 W/m2).

Jean-Marc

[mikeg123]

Hello all,

We are progressing more into our design process and have run into a problem.

The DAQ we are using is the NI USB 6009 DAQ, which we feel is sufficient. The problem is that we are also using a newer version of Labview, and the older (legacy?) VI we planned on using apparently has a sub-VI that isn't included on this newer version of Labview. Is it possible to swap this sub-VI (it's called AI Acquire Waveforms.vi) out with a newer sub-VI, or are we going to have to start from scratch? 

[smercurio_fc]

The AI Acquire Waveforms is part of Traditional DAQ. This is what was used before it was replaced with DAQmx. Traditional DAQ is still available, but your device is not supported by Traditional DAQ. With that device you must use DAQmx. There's lots of examples that ship with LabVIEW that show you how to use DAQmx. You can also look over: Transition from Traditional NI-DAQ to NI-DAQmx in LabVIEW and Learn 10 Functions in NI-DAQmx and Handle 80 Percent of Your Data Acquisition Applications.

[patek]

Thank you for the information .

please can you send me how o connect the electronic load with solar panel .

Appreciate if there is a video .

Thanks in advance .

Patek