Life cycle assessment of Internet of Things(IoT) solution in Södertälje municipality– A smart waste collection system

Internet of things (IoT) is expected to transform the way we live, work, and learn. Using IoT can be a game-changer for municipalities to move towards sustainability. Within the Vinnova financed project, the municipality wants to explore how IoT can enable route optimization and placement planning for increased operational efficiency. The aim of this study is to enhance the knowledge of the environmental benefits of IoT systems in the waste collection system in the city center of Södertälje. This life cycle assessment, LCA, will support the project by identifying environmental hotspots. The LCA study was performed in Jan-Sep 2021. The functional unit of the study has been set to 1 year of IoT system service for 160 litter bins in city center of Södertälje. The studied system is a cradle-to-grave system, including raw materials, sensors and gateways, use phase, and end of life the sensors and gateways, internet connection, as well as the cloud services. Inventory information have been collected mainly from Södertälje, suppliers, and the service providers. Generic data, such as electricity mix, and transports have been taken from the Ecoinvent database and literature. This study has evaluated the environmental impacts of IoT system in Södertälje for the case of smart waste collection system installed in the city center in a life cycle perspective. The objective of the study has been: 1. To estimate the environmental impact (with focus on climate change impact) of IoT system in Södertälje and find out the hotspots within the system in a life cycle perspective. The climate change impact of the IoT system solution in Södertälje is estimated about 120 kg CO2eq per year, which mainly contributes from the gateways (50%) and sensors (27%) and the use of internet (23%). 2. To estimate the environmental impact (focus on climate change impact) of the waste collection system (without IoT system) and find out the hotspots within the system. The climate change impact of the current waste collection system in the city centre of Södertälje contributes approximately 12t CO2eq per year, which mainly contributed from the use of fossil-based plastic trash bags (96%) and the HVO based transport (4%). 3. To compare the current with the future waste collection system (including IoT system for planning and service). To compare the current with the future waste collection system, we use scenarios (see Figure 20 for results). At the starting point of the study (scenario 1), we present results that are based on assumptions and have the same CO2 emissions for the transport and the trash bags. The results were based on diesel (50%) and recycled plastic trash bags (50%). The recycled plastic is made of 80% recycled LDPE and 20% virgin LDPE (Tingstad, 2021). The next step (scenario 2) of the study, we present results that are based on direct data of the current system. The results were based on HVO and fossil trash bags, which results into 11.5 t CO2 for fossil bags and 380 kg CO2eq per year for transport and 120 kg CO2eq extra for the IoT system. The last step (scenario 3) of the study, we present results that are based on future assumptions. The results were based on using no bags and no CO2 emission from bags, which results into 120 kg CO2eq for the IoT system and 380kg CO2eq for the transport and 0 kg CO2eq for the trash bags. The future waste collection system needs to be better than the current system. That means, the future waste collection system needs to reduce the CO2eq emissions by at least 120 kg CO2eq to break-even the extra IoT system. For the IoT system to have an effect, at least 32% of the transport (km) or the number of trash bags used need to be reduced (50 bins of 160 bins), in order to outweighs the extra CO2eq from the IoT system (Figure 21). - A reduction of trp km or trash bags by 32% reduce CO2eq by 120 kg. (=IoT system). - A reduction of trp km or trash bags by 64% reduce CO2eq by 240 kg. (> IoT system)