A Techno-Economic Analysis to Compare Low Voltage DC with AC Grids for LED Lighting

Modern lighting systems typically use LED lamps. State of the art is to employ AC/DC drivers, connected to the local low voltage AC (LVAC) grid. However, a local low voltage DC (LVDC) grid, using DC/DC drivers and a centralized rectifier, can be more economic. Currently, it is cumbersome to assess the LVDC alternative since simple to use methodologies are missing. In this study, the choice between LVAC or LVDC in the planning of the lighting system's local electrical grid is aided by a comparative Techno-Economic Analysis (TEA). The analysis comprises: the design of the grid components, the calculation of the losses therein and the determination of the costs. The TEA is applied to an exemplary 100-kW greenhouse using commercially available components, where it is found that the LVDC grid saves about 3% of costs compared to the LVAC solution.