Profitability assessment for self-sufficiency improvement in grid-connected non-residential buildings with on-site PV installations

In the last few years the photovoltaic market has seen a transformation from large ground-mounted field arrays towards small-scale, highly distributed roof systems connected to the low-voltage grid. Recent reductions in photovoltaic feed-in-tariffs, soaring retail electricity prices and a significant decrease in the cost of photovoltaic panels have fueled this transition to the schemes promoting local consumption with the grid connection used to compensate for any energy imbalances. Special attention has been paid to commercial and public buildings because of the requirements for their self-sufficiency and also for their potential for sizable photovoltaic generation. In this paper a simplified model of such self-sufficient system is introduced and then the sensitivity analysis applied for the principal economic factors that affect the profitability of the investment. A case study is used to demonstrate the methodology and provide the assessment results.