I'm designing a MPPT controller for a 1 KW PV system. I'm going to test the MPPT controller's efficiency during partial shading condition. For that i'm going to create the shading effects artificially. During that shading period i need to measure the insolation level (W/m2)of each panel. Is any other sensors or meters available other than pyranometer and lux meter ?
I disagree with Ashish: A lux meter does not measure irradiance but luminance.
Dear Bala,
There are several types of sensors available on the market. Some examples you can find here - http://www.campbellsci.com/solar-radiation. I think in your case suitable method is to determine inclined solar radiation, air temperature and energy output from each panel. Using efficiency curves you will be able to determine shaded/not-shaded area of the panel. The potential limitations - it is difficult to ensure that radiation in the shadowed area is equal to 0.
The Licor silicon sensor (LI-200) would be the typical low-cost instrument to use in this case.
I disagree with Ashish: A lux meter does not measure irradiance but luminance.
You will get more precise instant irradiance measurements (W/m2) using a pyranometer then you can integrate that in order to get in (wh/m2) if you want.
Many of them are available in the market (like kipp & Zonen, Eko...)
A pyranometer, with a shadow band stand, is the ideal instrument. One manufacturer is Epply laboratories. For a cheaper method use a thermopile. A description of such a measurement system is given in "Photovoltaic Systems - Analysis and design" by A. K. Mukerjee and Nivedita Thakur, PHI learning, 2014.
To have detailed guidelines for radiation measurements (of reference) you can look at the CIMO Guide from the World Meteorological Organization (WMO): GUIDE TO METEOROLOGICAL INSTRUMENTS AND METHODS OF OBSERVATIONS, Chapter 7 (see http-links below)
http://www.wmo.int/pages/prog/www/IMOP/CIMO-Guide.html
http://www.wmo.int/pages/prog/www/IMOP/publications/CIMO-Guide/Ed2008Up2010/Part-I/WMO8_Ed2008_PartI_Ch7_Up2010_CORR1_en.pdf
Some of the comments above are either incorrect or do not apply to the actual question, which is: "Is any other sensors or meters available other than pyranometer and lux meter ?"
There is thus no need to insist on pyranometers or luxmeters in this context.
To set the record straight, a pyranometer is a thermopile instrument. Eppley is just one manufacturer of such equipment, and not necessarily the best, as studies have shown. Eko, Kipp and Hukseflux are typically better. In any case, good pyranometers are expensive, whereas a simple Licor silicon sensor is much simpler and cheaper (but not as accurate of course).
A shadowband is only necessary to measure diffuse irradiance, which is obviously NOT what the question is about.
Simplest one for direct irradiance for me is: http://www.apogeeinstruments.com/pyranometer/
Is a silicon based sensor. They are very reliable. Voltage output (you can use labjack or NI usb DAQs very easily) and they are cheap.
I don't know why the OP needs to measure illuminance in a PV shadowing study. IMHO, basic irradiance, either with a simple Si based sensor or more sophisticated pyranometer system is enough. Iluminance would be more important for imaging (e.g. where the human eye is part of the system). Unless this is a spectrum splitting PV application I don't see the need for spectral data.
Dear contributors,
I would like to thank all of you, for taking the time to share your thoughts. I came across solar power meter which will measure the irradiance directly, the specification of the device is available in this link http://www.mecoinst.com/uploads/products/pdf/solar-power-meter.pdf. Can I use this in place of pyranometer ?. Kindly share your valuable thoughts.
If you absolutely need a portable handheld instrument, yes. It has a silicon detector, just as the Licor. The latter would be better (and cheaper?) for the more usual type of operation, in fixed/autonomous mode, i.e. permanently attached to PV arrays.
If you look for something different from a pyranometer, you can use a crystalline silicon reference solar cell. They work well to detect irradiance and if you have a technology matching your module technology you can reduce at the minimum the spectral response mismatch.
To get an idea look at this: http://www.nrel.gov/docs/fy12osti/55487.pdf
By the way, there are various wrong answers under your question. You cannot use a lux meter in this context, as well as a shaded pyranometer (used for diffuse irradiance). Moreover, direct irradiance is measured by a pyrheliometer not a pyranometer.
About the solar power meter you are referring to, it can work, but you have to answer yourself about what is the uncertainty that you want to have in your data.
The pyranometer is used in measuring solar insolation but its reading in milli-volt, Also the standard cell is used and it gives milli- mpere.
Use a pyranometer for solar irradiance. A lux meter only measures illuminance. Most people have a tendency to use a lux meter and then back calculating the lux values to get the power (W) per m2 based on the receiving pannel. This is wrong in that they assume a maximum luminous efficacy of 683 lumens/W to do their conversions. My advice to you, Use the right tool for the right job ;)
I am interested to measure the regional solar insolation not radiation directly. For this case could I use the solar power meter by Tenmars. Help me in this regard.
Finally which device do you used for measurement of solar radiation??
Am also facing the same problem hope you can help me out from this problem.
Dear respected Rajeev Kumar Chauhan,
I would prefer pyranometer in measuring solar irradiation,
Best regards
Kifilideen.
You can use PT202C phototransistor instead of pyranometer to measure the solar insolation level.
Regards
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