Energy payback time of grid connected pv systems: comparison between tracking and fixed systems

Resumen

A review of existing studies about LCA of PV systems has been carried out. The
data from this review have been completed with our own figures in order to calculate
the Energy Payback Time of double and horizontal axis tracking and fixed systems. The
results of this metric span from 2 to 5 years for the latitude and global irradiation ranges
of the geographical area comprised between −10◦ to 10◦ of longitude, and 30◦ to 45◦ of
latitude. With the caution due to the uncertainty of the sources of information, these
results mean that a GCPVS is able to produce back the energy required for its existence
from 6 to 15 times during a life cycle of 30 years.
When comparing tracking and fixed systems, the great importance of the PV generator
makes advisable to dedicate more energy to some components of the system in order to
increase the productivity and to obtain a higher performance of the component with
the highest energy requirement. Both double axis and horizontal axis trackers follow
this way, requiring more energy in metallic structure, foundations and wiring, but this
higher contribution is widely compensated by the improved productivity of the system.