The value of module efficiency in lowering the levelized cost of energy of photovoltaic systems

One standard that is used to compare different energy generation technologies or systems is the levelized cost of energy (LCOE). The relatively high LCOE of photovoltaics (PV) is an obstacle to adopting it as a major electricity source for terrestrial applications. In a conventional PV system, the cost of the module contributes approximately half of the expense and the other costs are together summarized as balance of system (BOS). A large portion of the BOS is not related to the peak power of the system, but can be either proportional to or independent of the total installation area. Across different PV systems with the same installation area, this part of BOS ($/W) is directly dependent on the module efficiency. Therefore, the LCOE is affected by the module efficiency even if the module price ($/W) remains the same. In this paper, we compare the LCOE across PV systems with equal installation areas but with modules of different efficiencies installed with fixed tilt, 1-axis tracking or 2-axis tracking. We conclude that: (1) at a given module price in $/W, more efficient PV modules lead to lower LCOE systems; (2) when meeting an LCOE goal, the PV module efficiency has a lower limit that cannot be offset by module price; and (3) both 1-axis and 2-axis tracking installations provide lower LCOEs than fixed tilt installations.