Life cycle impact assessment of home energy management systems (HEMS) using dynamic emissions factors for electricity in Finland

•HEMS did not reduce the overall environmental impact of households.•Environmental impacts of HEMS are greater for single inhabitant households.•Energy efficiency of sensing devices must drastically increase to promote decarbonisation.•The highest life cycle environmental impacts of electronics are during the manufacturing phase.•Raising awareness is a critical part in decreasing the environmental impact of households.

Decarbonising the European economy is a long-term goal in which the residential sector will play a significant role. Smart buildings for energy management are one means of decarbonisation, by reducing energy consumption and related emissions. This study investigated the environmental impacts of smart house automation using life cycle impact assessment. The ReCiPe method was selected for use, in combination with dynamic emissions factors for electricity in Finland. The results indicated that a high level of technology deployment may be counter-effective, due to high electricity consumption by the sensor network, automation system and computing devices. The results also indicated that number of inhabitants per household directly affected the environmental impacts of home automation. A single-person household saw its environmental impacts increase by 15%, while those of a five-person household increased by 3% in the worst-case scenario. The manufacturing phase contributed the major share of environmental impacts, exceeding the use phase in multiple categories. These findings indicate that finding the sweet spot in which technology can promote decarbonisation will be crucial to achieving the goal of a low‑carbon economy.