In this paper, the performance of a direct current (DC) distribution system is modelled and compared fora single-family residential building with a conventional alternating current (AC) system to quantify the potential energy savings and gains in PV utilization. The modelling is also made for two different climates to quantify the impact of the geographical location. Results show that the system losses are reduced by 19-46% and the PV utilization increased by 3.9-7.4% when using a DC distribution system compared to an AC equivalent, resulting in system efficiency gains in the range of 1.3-8.8%. Furthermore, it is shown that the geographical location has some effect on the system's performance and PV utilization, but most importantly the grid interaction is paramount for the performance of the DC topology.