The trolleybus traction grids, an effective electrification solution for urban transport, can become more sustainable and efficient through the direct integration of solar photovoltaic systems. Previous research shows different results for this application. The aim of this study is to identify a set of Key Performance Indicators (KPIs) and to study their effects on the feasibility of integrating PV in two trolleygrids, Arnhem (Nl) and Gdynia (Pl). This is done through the simulation of the yearly operation of the trolleygrids with PV systems integrated at substation level. It is demonstrated that the integration of PV in trolleybus traction grids can vary depending on the characteristics of the grid and the location. In particular, the increase in power demand, in number of sections served, in the traffic conditions and in the radiation and sunshine duration levels induces an improvement in the performance of PV. The average length of the sections supplied and the removal of the HVAC demand on the other hand, are not beneficial to the integration of PV. It is concluded that the potential of integrating PV in the Gdynia trolleygrid is higher than the one in Arnhem. It is also shown, that the introduction of storage always improves the PV potential.