senk007

Hello, I have a complete weather station from Davis and it also includes Solar Radiation Sensor (pyranometer). (Vantage Pro2 Plus with 24-Hr Fan Aspirated Radiation Shield) And I want to measure PR (Performance Ratio) daily/weekly/Monthly. I am confused with installation of a pyranometer . How should I install Pyranometer, shall I install straight horizontal (on a pole along with rain collector) or should I install at the same angle as Solar panels (on the solar structure as PoA mounting) I guess, if I install a horizontal flat, then it would measure GHI, in that case, I need to convert GHI to PoA, which I do not know how to convert. For PR calculation, which one is better method? Horizontal or at same angle of solar panel? I saw many solar installations and they almost always install at Panel angle. Like photo shown below. But many of them are also recommending installing at horizontal and then convert it to PoA using a long and lengthy calculation. Please suggest and help. Thanks Senk

Hello, my weather station is reporting Solar Radiation every minute in W/m2. I want to calculate daily & Monthly PR. How do I use my W/m2 (resolution is in a minute) into the following formula (GlobInc) PR = E_Grid / (GlobInc * Pnom) Please help. Following what it looks from my weather station Solar Radiation sensor. (minute wise) https://i.ibb.co/sj8g98m/2020-06-27-23-39-18.jpg

Oh ok...again Thanks for your help. I have attached excel file containing my POA data for a day. Then i made it hourly average and then did sum of all those hourly average. Please see attached excel file if it is correct. kWh/m2/day coming to 4.32 Please correct me if i am wrong anywhere. Thanks PR.rar

Thanks for your support. Here are some numbers: Total (sum) kW/m2 for 24 hours = 871 (my pyranometer reports irradiance every 15 sec. I summed values all value of last 24 hrs) E_Grid = 640 kWh Pnom = is it total installed capacity? in my case solar plant it 171kWp. But i seems i am doing something wrong here with numbers. PR = E_Grid / (GlobInc * Pnom) PR = 640 / (871 * 171) I have attached screenshot of actual installation report (PVsyst)

Hello i wan to calculate how our install Solar Plant (150kw) is performing. We have weather station installed at our solar site and it reports POA value in realtime. I do have other things ready such as Total solar panel Area (m2) (which is 954 m2 as Module area and 851 m2 as Cell area) solar panel yield or efficiency(%) (which is 17.5% in our case) I do not know how to use POA value from weather station in the calculation of PR. Do i sum POA value of entire day? Do i take avg by sum and dividing it by 24 hr? As per PVsyst report in the month of October, GlobInc for my site is 191.3 kWh/m2 I was reading number from my weather station, which gives around 600 POA at noon time. Pls let me know how to calculate this. Thanks Nirav