How and Where Should One Install the Weather Monitoring Station on the Solar Plant?
Location of the weather monitoring station significantly affects the data gathered and reported by it. It is observed that many times, WMS is installed at such locations that it gives incorrect data about the various parameters, killing the entire purpose of installing a weather monitoring station.
Here are some pointers, one should keep in mind while installing a WMS.
The weather sensors along with GHI pyranometer of WMS should be installed on a single mast or pole. It is recommended to install the GTI pyranometer on the nearest solar PV module itself. This will ensure that the GTI pyranometer angle is same as the modules. This eliminates the human intervention and error while manually setting the angle of the pyranometer.
In case, the GTI pyranometer cannot be installed on PV module, the same can be installed on the pole (mast) along with other sensors. In this case, the mounting base for the GTI pyranometer should preferably have angles marked on it, so that user can precisely set the angle of the GTI pyranometer with respect the seasonal tilt angle of the solar PV modules.
While selecting the location of installation of WMS, one must ensure that there are no high rising buildings or tress near the pole. The pyranometers should be free from any shadows throughout the day. The wind speed and wind direction sensors should not have any structure nearby that can obstruct the wind flow. Care should also be taken that the pole or mast does not cast a shadow over GTI pyranometer or the PV modules.
If the solar power plant is in northern hemisphere, then both the pyranometers must be installed pointing in south direction. The anemometer (wind speed and wind direction sensor) should be opposite to the pyranometer, i.e., the wind vane should point north. The top of the rain gauge should be free from any shade or obstacle. The module temperature sensor should be fixed at the back of the PV module. It is recommended to fix the module temperature sensor at the back of the PV module where the GTI pyranometer will be installed. The other sensors like air temperature and humidity sensor can be installed at any position on the pole. The cable lengths required for sensors should be minimised.
If one follows all the instructions mentioned above, the data captured by the various sensors would be free from any distortions and can be used further to draw conclusions about the plant performance.