Principle Formula Calculator

Calculation of solar photovoltaic power and energy.


The principle of solar photovoltaic is to convert solar energy of light (photons) into electricity. When photons heat special materials they create a displacement of electrons that generate a continuous current. Solar cells are connected in series to form photovoltaic panels that are connected together to crate a PV generator. This generator can be connected to an inverter to transform continuous current in alternative current 3-phase or single phase and connected to the grid or to a storage system.

Formula to calculate PV energy

How to calculate annual output energy of a solar photovoltaic (PV) system? The simplest formula is :
formula photovoltaic energy
Where :
   E = electric energy PV production (kWh/year)
   Hi = global incident radiation (kWh/m²/year)
   Pstc = sum of peak power at STC conditions of photovoltaic solar panels (kWp)
   PR = Performance ratio of the solar PV system (without unit)

Calculator : solar PV energy and financial gain

Enter your own values in the white boxes, results are displayed in the green boxes.

Power of solar panels, Pstc : kWp
Global incident radiation, Hi :   kWh/m²/year
Performance ratio, PR :   without unit
The performance ratio include all losses of the photovoltaic solar system : temperature derating, inverter yield, losses in cables, losses due to snow and smear and dust... A typical value of PR is between 0.7 and 0.8.
Average annual energy in output of solar PV generator :     kWh/year
Cost of energy :  /kWh
Total annual amount of electricity bill : /year