Environmental impacts of small-scale hybrid energy systems: Coupling solar photovoltaics and lithium-ion batteries

Abstract

One of the benefits of hybrid solar PV-battery systems is that they can reduce grid dependency and help balance electricity supply and demand. However, their environmental impacts and benefits remain underexplored. This study considers for the first time life cycle environmental impacts of domestic-scale PV-battery systems in Turkey, integrating multi-crystalline PV and lithium-ion battery. The impacts were estimated for both individual installations and at the national level, considering different regions across the country and taking into account their insolation and other climatic differences. Electricity generation and storage were modelled on an hourly basis taking into account consumer behaviour. The results show that the system can meet between 12.5% and 18.4% of the household's annual electricity needs. On a life cycle basis, it generates 4.7-8 times more energy than it consumes. Solar PV is the major contributor to most impacts (75%-81%). An exception is human toxicity which is mainly due to the battery (66%). The hybrid system has 1.6-82.6 times lower impacts than grid electricity. Assuming a very modest uptake at the national level (2%-8%), the use of hybrid systems would save 558,000 t CO2-eq./yr compared to grid electricity. Thus, these results demonstrate clearly the environmental benefits of these hybrid systems. Together with the financial and energy security benefits for both the country and the consumer, this provides a strong impetus for their wider deployment. However, this will be difficult to achieve, as there are no incentives for battery storage. Therefore, it is recommended that relevant legislation be introduced to stimulate future uptake of hybrid PV-battery systems. (C) 2018 Elsevier B.V. All rights reserved.