Solar Made Life Easy: Question & Answer : Part II

Sun Questions & Answers

 
Question:  


I have a question, we add the voltages of panel together and add the power( in watts)of each panel together you calculate the max. amount of power and voltage the solar will generate, and on other hand in one of the book its written that 4 panels, each on have 12V and power 20W and when connect in series it will be 48V, 80W array. I think in this case, we have to connect in parallel with another 4 panels with the same V and W to get 48V and 80W.
Best regard
     
Answer: 

With regards to your question, when you connect solar panels in series, both the voltage and the power increase, whilst the current remains the same. When you connect solar panels in parallel, the power and the current increase, whilst the voltage remains the same.
Let me explain another way, using the example of a 12v 12w solar panel (I'm using 12w because this equals 1 amp at 12v, which makes the maths easier).

If you take one 12v 12w panel, your solar panel provides 1 amp of current at 12 volts. If you take four
12v 12w panels and connect them in series, the power and the voltage is multiplied by four - so you have 48v at 48w, but your current remains the same - 1 amp.

If you then take four 12v 12w panels and connect them in parallel, the power and the current is multiplied by four - so you have 12v at 4 amps, but your voltage remains the same - 12v.

I hope this answers your question.