[werk_ag]

Today I tried to measure the voltage produced by my photodiode with a 235 ohm R in parallel. I recorded a maximum of 330 mV (weather stations near me have recorded about 660 w / m 2). I believe that by calibrating a little the resistance we can get a 1.1 volt (considering that from me 1300 w / m2 have a limit more than ample))

Just be aware of this:

"There is a trade-off between the desire to increase the output voltage (by increasing the resistance) and the need to make sure that the pyranometer output remains linearly proportional to the incident sunlight. "

This is from the link you published. It's valid for my solar sensor and probably for any other that use the same principle.