When sizing electric cables for PV installations it is a common practice to select cabling that meets the minimum regulatory requirements. This is done to minimize upfront costs. However, choosing a larger cable cross section than legally required reduces energy losses. The purpose of this paper is to establish the optimal cable cross-section for a PV installation that will minimize its life cycle cost.
In some countries, the allocated price for electricity generated by PV systems is higher than the market price thanks to the feed-in tariff or green certificates. When this is the case, energy losses become even more costly. In other words, reducing the energy losses of a PV plant by increasing the cable cross-section leads to an even bigger financial return than in other electrical installations.
The PV installation layout is one of the determining factors for establishing the length and minimum cross-section of each cable. A careful study of all the lay-out options can significantly lower the life-cycle cost of the installation.