It is known that a solar panel can convert only a fraction of the solar energy it receives into electricity. What range of efficiencies can we affect to solar panels? Is it possible to have a table of efficiencies in time (seasons) and space (regions) ?

The efficiency of a solar panel in a certain region and time will depend among other things, on what specific panel you are using. The necessary meteorological data can be found at openly accessible databases such as at https://re.jrc.ec.europa.eu/pvg_tools/en/#PVP

One you have the radiance and temperature for your location at your time of interest, you can use formulas to calculate the losses in your panel. These formulas are shown in Chapter 4 of our book, available at The Solar Hub – Solar pumping for water supply: harnessing the power of the Sun