Thermal Loss Factors - Uc & Uv to be considered in PVSyst for Floating PV Plants

[shamimsiddiqui]

Hi,

We are installing a 10 MWp Floating Solar PV plant in madhya Pradesh state of India.
Request you to please provide your recommendation for values of Thermal Loss Factor - constant component Uc as well as wind velocity component Uv  to be considered for Floating PV plant.
Modules will be tilted 5 degrees and the pond is open from all sides, ambient temperature is approximately 45 deg C during summer and 5 deg C during winter.
Kinldy let me know if you needd any other detail/data from my side.
Thanks,

Regards,
Shamim Siddiqui

[Lazare Fesnien]

Hi, 

In PVsyst there is no specific parameter for simulating floating PV installations. You might consider using a modified ambient temperature to account for the fact, that close to the water surface the temperature is generally lower during the day. So far I have not seen systematic studies on this, and there is no published model to account for this effect, so the best you can do, is to perform a direct measurement yourself.

In PVsyst the relative humidity is only used to estimate precipitable water, in order to perform a spectral correction. This should be the humidity in the atmosphere above the PV installation and not the local humidity close to the PV modules. Therefore it should not change whether you have a floating system or a ground-mounted one.

The albedo of water is generally lower than the one of land, so you might adapt this in the project parameters.

PVsyst has no model to simulate the waving effects of water.

[DavidCoh]

Hi 

Following the Shamim question above I would like to know if I have already some PV plants installed, on ground and on water, with some temperature records, on the panels and the ambient, how can I calculate an average of the resulted Uc along the years?

is there any equation I can use for checking during the previous years, according to the Ambient/Panel temperature ratio, what was the real Uc factor to be used?

many thanks

David.