Greenhouse Gas Emissions Associated with an Energy Harvesting Farm based on Stationary Bicycles

Energy harvesting from human kinetic activity, particularly through physical exercise, can simultaneously address energy sustainability and public health concerns. This study employs the Life Cycle Assessment methodology to evaluate the environmental impact of an energy harvesting system comprising 32 stationary bikes, operating in bi-hourly sessions of 20 minutes each, eight hours a day, over a 10-year period. Greenhouse gas emissions associated with the material composition of the energy system are quantified and compared to the Brazilian electricity matrix. The findings reveal that the emission factor of the electrical energy harvesting farm is 0.064 kg CO2-eq/kWh, significantly lower than that of the Brazilian national electric grid 0.152 kg CO2-eq/kWh, demonstrating its potential to reduce carbon emissions. The energy return on investment of the system, defined as the ratio between electricity generated and human metabolic energy, is approximately 0.17. Beyond environmental benefits, such systems encourage physical activity, contributing to reduced healthcare costs associated with sedentary lifestyles. This research underscores the dual impact of energy-harvesting exercise systems, presenting a scalable solution for sustainable energy generation while promoting public health and well-being. The results provide valuable insights for policymakers and urban planners in integrating such innovations into sustainable energy strategies.