This area chart visualizes 24 months of synthetic household electricity usage in kWh. The filled area emphasizes the magnitude of values relative to a zero baseline, with an overlaid line and interactive dots. Built as a reusable D3 component using d3.area and d3.line, it renders in SVG with animated updates. The chart includes axes, gridlines, axis labels, and a hover tooltip, all managed through D3 v7 selection joins and the public update method.