Autonomous photovoltaic system for a pen for building materials in Patras that consisted of 4 photovoltaic Qcells. Q.peak mono 305Wp-1, Victron Bluesolar 50A MPPT-1 charge regulator, Victron Multiplus 3kVA-12 inverter, Sunlight GEL opzv 2V-535Ah batteries. This autonomous photovoltaic system will supply the lights with power, the security system (cameras, recorders), a small fridge and a laptop. It will provide 1-3Kwh daily in the winter and 5-7Kwh in the summer. The energy stored in the batteries exceeds that of 13Kwh, while the momentary power is almost 5kva (4kw).