Analysis of Grid Flexibility in 100% Electrified Urban Energy Community: A Year-Long Empirical Study

Abstract

This study presents a year-long empirical analysis of a fully electrified urban energy community, a key step towards achieving “carbon neutrality” in the building sector. Integrating residential and non-residential buildings, it explores the impact of operational dynamics and energy sharing on grid flexibility, resulting from maximizing renewable energy and complete HVAC system electrification. Achieving annual energy self-sufficiency rates of 66.1% (based on total electrical production and consumption) and 126.3% (under South Korea's zero-energy standard), the community realized a 57.7% self-consumption rate. Using machine learning clustering for pattern analysis combined with domain-based interpretation, it unraveled complex interactions between building operations and the power grid, influenced by external factors (weather, occupant behavior), system design, and controls. Managing low-probability high-impact events of severe demand or production peaks, accounting for only 0.5% of the time and 1.8% of net energy annually, was crucial for grid stability and cost reduction. The study highlighted the limitations of increasing battery energy storage capacity in certain environments, emphasizing demand-side management, particularly thermal systems. Net demand profile-based control with thermal storage-linked electric boiler and heat pumps effectively reduced grid stress and operational costs, with a 29.7% decrease in annual demand charges and an 18.3% reduction in electricity costs.

Keywords: Electrified building, Grid flexibility, Energy flexibility system, self-sufficiency, Demand-side management