The use of renewable technologies will increase with the requirement to meet carbon reduction targets. However, this must be done in a sustainable manner. This paper compares the impact of the current Lebanese electricity system with production of electricity from PV. This is the first paper to look at how the addition of PV to this system, and explores the potential impact. As many electricity networks in the region suffer from similar issues and have similar climates this research will not only inform the Lebanese system, but can be used to influence and inform impacts of other systems. It evaluates the environmental impact, and therefore the actual sustainability, of a 1.8kWp monocrystalline Photovoltaic (PV) system with and without Lead-Acid batteries (PbA) compared to the existing centralised electricity production mix and decentralised diesel neighbourhood gensets. The analysis is rigorous as it is conducted using the methodology of life cycle assessment (LCA), using the SimaPro software (Ecoinvent 2.2 database) and ReCiPe 2008 method for impact assessment. The environmental impacts of the PV technology are compared to that of the existing fossil fuel electricity generation mix. Results, using the functional unit of 1kWh, indicate that the PV system, even when equipped with PbA batteries, has a lower environmental burden per delivered output compared to the Lebanese electricity mix, and even more so when decentralised diesel neighbourhood gensets are taken into account. The results of the analysis allows to calculate a series of parameters such as Global Warming Potential (GWP) (0.0402kg CO2eq/kWh and 0.0389kg CO2eq/kWh), Cumulative Energy Demand (CED) (4.41MJ/kWh and 4.39MJ/kWh), Gross Energy Requirement (GER) (1.23 and 1.22), Energy Pay-Back Time (EPBT) (16.9years and 16.1years), Carbon Dioxide Pay-Back Time (CO2eqPBT) (3.52years and 3.21years), and Net Energy Ratio (NER) (1.48 and 1.55) for the PV system with and without PbA batteries.