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PHOTOVOLTAIC - SOLAR CELL TECHNOLOGY

PV System energy output calculation

A rough indication of the annual electricity output from a PV system may be obtained by the simplified formula:

SEO = PR x P x H

Where:

  • SEO = System energy output (kWh/y)
  • PR = performance ratio (% )
  • P = rated power (kWp)
  • H = solar irradiation in plane of modules (kWh/m² y)

The performance ratio (PR) accounts for the reduction in system output caused by losses associated with battery storage, inverters, resistance of wiring and load matching.

It depends on the system design and on the application.

Typical values of PR for grid conneceted systems : 70 to 80% with the inverter accounting for much of the loss.

Example A grid connected array of 1 kWp capacity, installed at a site with an annual solar irradiation in the plane of the module of 1500 kWh/m2 (typical of southern Europe).

Assuming a performance ratio of 80%, the annual energy output will be 1200 kWh.

You can introduce your own data in the following table:
definition symbol
value
 suggested value unit
Performance ratio PR 70 - 80 %
Rated power P   kW
Solar irradiation H 1500 kWh/m²*y
     
System Energy Output SEO   kWh/y

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