Energy Footprint and Carbon-Emission Reduction for small Lagoon Treatment Using Off-The-Grid Solar-Powered Mixing

ABSTRACT - Mixing is the energy driver for the facultative lagoons used in wastewater treatment. We studied the comparative scenarios of an existing grid-powered mixer and a solar-powered mixer. Testing was conducted to monitor the water quality, energy consumption and carbon emission changes to evaluate the feasibility to use off-grid solar-powered mixer in lagoon treatment. In each test, water quality was tested in field to guarantee the performance of the solar-powered mixer. The energy usage was recorded with the electrical energy monitor by the wastewater treatment utility. The result shows that after the replacement, both energy usage and cost have a significant reduction, the energy usage having decreased by 70% and the cost by 47%. Additionally, carbon-equivalent emission from electricity importation dropped by 64%, with an effect on the overall carbon emissions (i.e., including all other contributions from the process) decreasing from 3.5% to 1.3%.