Wire diameter optimisation

Wire sections are determined by the maximum allowable current and the ohmic resistance.

The proposed wire diameters are automatically limited to the minimum allowable cross-section according to European standards for isolated wires installed in visible conduits.

For a given global loss target (at STC—i.e., maximum operating current), the program determines the best wire cross-section to minimize either:

• The total copper mass, or
• The total wiring cost (if you have defined the specific installation price for each wire size in Wires)

Note that ohmic losses follow a quadratic relationship with array current (\(Ploss = R · I²\)), so the loss ratio decreases linearly with output current. For example, wiring losses of 1% at STC will result in 0.5% loss at 500 W/m². Therefore, average wiring losses over the whole year are much lower (approximately half for European climates).