Distributed Generation (DG) installation in the distribution system aimed to reduce power losses, increase the voltage profile, and increase the amount of power supplied. One DG that can be implemented is based on photovoltaic (PV). The stochastic PV characteristics will cause ups and downs of the power produced. When the power generated is greater than the load downstream, it will potentially cause the power flow to be two-way. The method for determining the placement location and optimal DG capacity is needed so that the effect of PV penetration on changes in power flow and voltage profile is still within the permissible limits.This study proposed the FPA algorithm to determine the optimal location and DG capacity to reduce power losses in the distribution system with a case study of distribution network in Semanu Substation, Gunung Kidul Yogyakarta. The findings confirmed that the FPA method can be used to determine the placement location and optimal DG capacity of 9.501 MW, with active power losses after DG having decreased by 68.75%, and reactive power losses of 61.40%.