This study aims at evaluating the production costs of photovoltaic plants that includes the impacts of adding new photovoltaic installations in the existing energy system via the use of the metric “system LCOE”. In the system LCOE, the Levelized Cost of Electricity concept is enlarged to incorporate the so-called integration costs: i.e. the costs of reinforcing the grid infrastructure to accept the increase of variable renewable sources production and the effects on the operating conditions of the existing fossil fuels power plants. These costs are applied to utility-scale photovoltaic plants with and without storage to analyse how their market parity and profitability would change in the future if a more systematic approach is used to evaluate their production costs. The results of themarket parity highlight that its achievement will not be compromised when the integration costs are considered, mainly thanks to the strong decrease of the investment costs of PV and BESS components.