Today, I've done some measurements of sun noise, using my setup for QO-100. Dish 95 cm, LNB Sat-Signal unmodified, and RSP1A, using SDR Console feature of Signal History, that creates CSV file with all the required information.
I measured at 10.600 MHz to avoid the effect of QO-100 transponder base noise on Wide USB 10 Khz BW.
After some excel work the results were +3. dB Noise increase. See picture.