A Case Study on Carbon and Water Footprint Evaluation of 120Wp Rural Household Photovoltaic System

The energy access gap represents an extremely important challenge for developing countries like Peru and due to the geographical diversity, the remoteness of rural communities and the low purchasing power of users, bringing electricity through conventional networks is very difficult. This study uses the Life Cycle Analysis (LCA) to evaluate the magnitude of the environmental impact, in terms of global warming potential, and water footprint throughout the 20 years of useful life of a rural electrical energy concession comprised of 120Wp Households photovoltaic systems (HPS). The isolated communities of San Martin, in the Peruvian Amazon region, was chosen for this study. The quantification of the matter and energy flow in the LCA of a product is carried out in the inventory stage; it is called Life Cycle Inventory Analysis (LCI). On the other hand, due to the particular conditions of the system (installation, operation, maintenance, monthly tariff collection), it is necessary to know its real impact and sustainability; not only through the aforementioned environmental impact indicators but also by energy intensity values required by the system throughout its life cycle. Therefore, this paper used the Cumulative energy demand (CED) method to determine the amount of energy taken from natural resources for each process involved in the LCA and calculated with this, i.e., the Energy Payback Time (EPBT) of the whole system. Like- wise, the HPS has been environmentally compared to other case studies and the Peruvian Energy Mix, revealing a lower impact in the latter case and results within the range for stand-alone systems. Throughout the stages of manufacturing, transportation, installation and 20 years of Operation, maintenance, and billing, the analyzed HPS presents environmental impacts in the climate change category in the amount of 0.14616 kg CO2 eq/kWh and a 0.00053 m3/kWh of water footprint. Besides, the HPS shows a strong relation between energy production and O&M conditions. Additionally, this study allows a further promotion of the use of this type of system in isolated areas, as well as the diversification of electricity generation in Peru.